Clinical Focus


  • Diagnostic Radiology
  • Radiology

Academic Appointments


Administrative Appointments


  • Gastrointestinal Oncology Tumor Board, Stanford (1997 - Present)
  • Genito-Urinary Tumor Board, Stanford (2010 - Present)
  • Breast Cancer Disease Management Group Member, Stanford Cancer Center (2007 - Present)
  • Chief, Breast MRI Service, Stanford (2006 - Present)

Honors & Awards


  • Lauterber Award in MR, Society of Computed Body Tomography and Magnetic Resonance (2008)
  • Second Place Poster Awarded [Contributing Author], 5th Interventional MRI Symposium (2004)
  • Winner, Young Investigator Award competition, Association for Advancement of Medical Instrumentation (AAMI) (2004)
  • Elected Fellow, Society of Computed Body Tomography and Magnetic Resonance (2002)
  • Winner of best paper award (North America) [Contributing Author], ESUR-SUR (2002)
  • Cum Laude Award [Advisor to award recipient, Rebecca Fahrig, Ph.D.], SCBT/MR (2001)
  • Finalist, Young Investigator Competition [Advisor to first author Janaka Wansapura, Ph.D.], Association for Advancement of Medical Instrumentation (AAMI) (2001)
  • Fellowship Research Trainee Prize [Advisor to award recipient, Rebecca Fahrig, Ph.D.], RSNA 2000 Physics Subcommittee (2000)
  • Moncada Award for an Outstanding Scientific Paper on Cross Sectional Imaging, Society of Computed Body Tomography and Magnetic Resonance (2000)
  • Picker/AUR Faculty Development Program Recipient, - (1999)
  • Gary Becker Award for Outstanding Interventional Radiology Paper, - (1998)
  • Cum Laude Award for an Outstanding Scientific Paper on Cross Sectional Imaging, Society of Computed Body Tomography and Magnetic Resonance (1996)
  • Recipient of National Cancer Institute Cancer Imaging Training Grant Fellowship, Stanford University Department of Radiology (1995-97)
  • Outstanding Scientific Paper by a House Officer, University of Michigan Medical Center Department of Radiology (1995)
  • Outstanding Scientific Paper by a House Officer, University of Michigan Medical Center Department of Radiology (1994)
  • Highest Honors in Physics, Williams College (1985)
  • Howard Stabler prize for honors thesis in Physics, Williams College (1985)
  • Magna Cum Laude, Williams College (1985)
  • Sigma Xi, Williams College (1985)
  • Phi Beta Kappa, Williams College (1984)

Professional Education


  • Fellowship: Stanford University Radiology Fellowships (1997) CA
  • Residency: University of Michigan Radiology Residency (1995) MI
  • Board Certification: American Board of Radiology, Diagnostic Radiology (1995)
  • Internship: Mount Sinai Medical Center (1991) NY
  • Medical Education: Harvard Medical School (1990) MA
  • BA, Williams College (1985)
  • MD, Harvard Medical School, Medicine (1990)

Current Research and Scholarly Interests


1. MRI of Breast Cancer, particularly new techniques. Currently being explored are techniques including ultra high spatial resolution MRI and contrast-agent-free detection of breast tumors.

2. MRI-guided interventions, especially MRI-compatible remote manipulation and haptics

3. Medical Mixed Reality. Currently being explored are methods of fusing patients and their images to potentially improve breast conserving surgery, and other conditions.

Clinical Trials


  • Magnetic Resonance Imaging of Breast Cancer Recruiting

    To compare magnetic resonance imaging (MRI) with more well established diagnostic imaging techniques to determine which method best finds and defines breast cancer.

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  • Accelerated Partial Breast Irradiation Following Lumpectomy for Breast Cancer Not Recruiting

    To determine whether an accelerated course of radiotherapy delivered to the lumpectomy cavity plus margin using IORT as a single dose, intracavitary brachytherapy with the MammoSite device over 5 days, partial breast 3-D CRT in 5 days, or stereotactic APBI over 4 days is a feasible and safe alternative to a six and a half week course of whole breast radiotherapy. The study will measure both short and long-term complications of radiation treatment, short and long-term breast cosmesis, local rates of in-breast cancer recurrence, regional recurrences, distant metastases, and overall survival.

    Stanford is currently not accepting patients for this trial. For more information, please contact Sally Bobo, (650) 736 - 1472.

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  • High Resolution 3D Diffusion-weighted Breast MRI Not Recruiting

    The purpose of this study is to determine how well a new MRI technique called "High resolution 3D diffusion-weighted breast MRI" detects breast cancer.

    Stanford is currently not accepting patients for this trial. For more information, please contact Sumita Sood, 650-723-0618.

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  • Phase 2 Anastrozole and Vandetanib (ZD6474) in Neoadjuvant Treatment of Postmenopausal Hormone Receptor-Positive Breast Cancer Not Recruiting

    In this study we plan to study the combination of ZD6474, a dual inhibitor of EGFR and VEGFR-2 with anastrozole in the neoadjuvant setting for patients with Stage I-III breast cancer. The aim is to overcome mechanisms of resistance and simultaneously block multiple critical signaling pathways known to stimulate breast cancer.

    Stanford is currently not accepting patients for this trial. For more information, please contact Marcy Chen, (650) 723 - 8686.

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2021-22 Courses


All Publications


  • Biopsy Marker Localization with Thermo-Acoustic Ultrasound for Lumpectomy Guidance. Medical physics Dixit, N., Daniel, B. L., Hargreaves, B. A., Pauly, J. M., Scott, G. C. 2021

    Abstract

    PURPOSE: Almost one in four lumpectomies fails to fully remove cancerous tissue from the breast, requiring reoperation. This high failure rate suggests that existing lumpectomy guidance methods are inadequate for allowing surgeons to consistently identify the proper volume of tissue for excision. Current guidance techniques either provide little information about the tumor position or require surgeons to frequently switch between making incisions and manually probing for a marker placed at the lesion site. This article explores the feasibility of thermo-acoustic ultrasound (TAUS) to enable hands-free localization of metallic biopsy markers throughout surgery, which would allow for continuous visualization of the lesion site in the breast without the interruption of surgery. In a TAUS-based localization system, microwave excitations would be transmitted into the breast, and the amplification in microwave absorption around the metallic markers would generate acoustic signals from the marker sites through the thermo-acoustic effect. Detection and ranging of these signals by multiple acoustic receivers on the breast could then enable marker localization through acoustic multilateration.METHODS: Physics simulations were used to characterize the TAUS signals generated from different markers by microwave excitations. First, electromagnetic simulations determined the spatial pattern of the amplification in microwave absorption around the markers. Then, acoustic simulations characterized the acoustic fields generated from these markers at various acoustic frequencies. TAUS-based one-dimensional (1D) ranging of two metallic markers - including a biopsy marker that is FDA-approved for clinical use - immersed in saline was also performed using a bench-top setup. To perform TAUS acquisitions, a microwave applicator was driven by 2.66 GHz microwave signals that were amplitude-modulated by chirps at the desired acoustic excitation frequencies, and the resulting TAUS signal from the markers was detected by an ultrasonic transducer.RESULTS: The simulation results show that the geometry of the marker strongly impacts the quantity and spatial pattern of both the microwave absorption around the marker and the resulting TAUS signal generated from the marker. The simulated TAUS signal maps and acoustic frequency responses also make clear that the marker geometry plays an important role in determining the overall system response. Using the bench-top setup, TAUS detection and 1D localization of the markers was successfully demonstrated for multiple different combinations of microwave applicator and metallic marker. These initial results indicate that TAUS-based localization of biopsy markers is feasible.CONCLUSIONS: Through microwave excitations and acoustic detection, TAUS can be used to localize metallic biopsy markers. With further development, TAUS opens new avenues to enable a more intuitive lumpectomy guidance system that could help to achieve better lumpectomy outcomes.

    View details for DOI 10.1002/mp.15115

    View details for PubMedID 34287972

  • Multishot Diffusion-Weighted MRI of the Breast With Multiplexed Sensitivity Encoding (MUSE) and Shot Locally Low-Rank (Shot-LLR) Reconstructions. Journal of magnetic resonance imaging : JMRI Hu, Y., Ikeda, D. M., Pittman, S. M., Samarawickrama, D., Guidon, A., Rosenberg, J., Chen, S., Okamoto, S., Daniel, B. L., Hargreaves, B. A., Moran, C. J. 2020

    Abstract

    BACKGROUND: Diffusion-weighted imaging (DWI) has shown promise to screen for breast cancer without a contrast injection, but image distortion and low spatial resolution limit standard single-shot DWI. Multishot DWI methods address these limitations but introduce shot-to-shot phase variations requiring correction during reconstruction.PURPOSE: To investigate the performance of two multishot DWI reconstruction methods, multiplexed sensitivity encoding (MUSE) and shot locally low-rank (shot-LLR), compared to single-shot DWI in the breast.STUDY TYPE: Prospective.POPULATION: A total of 45 women who consented to have multishot DWI added to a clinically indicated breast MRI.FIELD STRENGTH/SEQUENCES: Single-shot DWI reconstructed by parallel imaging, multishot DWI with four or eight shots reconstructed by MUSE and shot-LLR, 3D T2 -weighted imaging, and contrast-enhanced MRI at 3T.ASSESSMENT: Three blinded observers scored images for 1) general image quality (perceived signal-to-noise ratio [SNR], ghosting, distortion), 2) lesion features (discernment and morphology), and 3) perceived resolution. Apparent diffusion coefficient (ADC) of the lesion was also measured and compared between methods.STATISTICAL TESTS: Image quality features and perceived resolution were assessed with a mixed-effects logistic regression. Agreement among observers was estimated with a Krippendorf's alpha using linear weighting. Lesion feature ratings were visualized using histograms, and correlation coefficients of lesion ADC between different methods were calculated.RESULTS: MUSE and shot-LLR images were rated to have significantly better perceived resolution (P<0.001), higher SNR (P<0.005), and a lower level of distortion (P<0.05) with respect to single-shot DWI. Shot-LLR showed reduced ghosting artifacts with respect to both MUSE (P<0.001) and single-shot DWI (P<0.001). Eight-shot DWI had improved perceived SNR and perceived resolution with respect to four-shot DWI (P<0.005).DATA CONCLUSION: Multishot DWI enables increased resolution and improved image quality with respect to single-shot DWI in the breast. Shot-LLR reconstructs multishot DWI with minimal ghosting artifacts. The improvement of multishot DWI in image quality increases with an increased number of shots.LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.

    View details for DOI 10.1002/jmri.27383

    View details for PubMedID 33067849

  • Prognostic values of quantitative and morphological parameters of dbPET in patients with luminal-type breast cancer: A pilot study Miyake, K., Nakamoto, Y., Ikeda, D., Iagaru, A., Daniel, B., Lipson, J., Pal, S., Mittra, E., Guo, H., Kanao, S., Kataoka, M., Toi, M., Togashi, K. SOC NUCLEAR MEDICINE INC. 2020
  • Pure Fibrocystic Change Diagnosed at MRI-guided Vacuum-assisted Breast Biopsy: Imaging Features and Follow-up Outcomes JOURNAL OF BREAST IMAGING Chen, S., Okamoto, S., Daniel, B. L., Covelli, J., DeMartini, W. B., Ikeda, D. M. 2020; 2 (2): 141–46

    View details for DOI 10.1093/jbi/wbz090

    View details for Web of Science ID 000604353200008

  • Clumped vs non-clumped internal enhancement patterns in linear non-mass enhancement on breast MRI Chen, S., Covelli, J., Okamoto, S., Daniel, B., DeMartini, W., Ikeda, D. AMER ASSOC CANCER RESEARCH. 2020
  • Diffusion-weighted double-echo steady-state with a three-dimensional cones trajectory for non-contrast-enhanced breast MRI. Journal of magnetic resonance imaging : JMRI Moran, C. J., Cheng, J. Y., Sandino, C. M., Carl, M. n., Alley, M. T., Rosenberg, J. n., Daniel, B. L., Pittman, S. M., Rosen, E. L., Hargreaves, B. A. 2020

    Abstract

    The image quality limitations of echo-planar diffusion-weighted imaging (DWI) are an obstacle to its widespread adoption in the breast. Steady-state DWI is an alternative DWI method with more robust image quality but its contrast for imaging breast cancer is not well-understood. The aim of this study was to develop and evaluate diffusion-weighted double-echo steady-state imaging with a three-dimensional cones trajectory (DW-DESS-Cones) as an alternative to conventional DWI for non-contrast-enhanced MRI in the breast. This prospective study included 28 women undergoing clinically indicated breast MRI and six asymptomatic volunteers. In vivo studies were performed at 3 T and included DW-DESS-Cones, DW-DESS-Cartesian, DWI, and CE-MRI acquisitions. Phantom experiments (diffusion phantom, High Precision Devices) and simulations were performed to establish framework for contrast of DW-DESS-Cones in comparison to DWI in the breast. Motion artifacts of DW-DESS-Cones were measured with artifact-to-noise ratio in volunteers and patients. Lesion-to-fibroglandular tissue signal ratios were measured, lesions were categorized as hyperintense or hypointense, and an image quality observer study was performed in DW-DESS-Cones and DWI in patients. Effect of DW-DESS-Cones method on motion artifacts was tested by mixed-effects generalized linear model. Effect of DW-DESS-Cones on signal in phantom was tested by quadratic regression. Correlation was calculated between DW-DESS-Cones and DWI lesion-to-fibroglandular tissue signal ratios. Inter-observer agreement was assessed with Gwet's AC. Simulations predicted hyperintensity of lesions with DW-DESS-Cones but at a 3% to 67% lower degree than with DWI. Motion artifacts were reduced with DW-DESS-Cones versus DW-DESS-Cartesian (p < 0.05). Lesion-to-fibroglandular tissue signal ratios were not correlated between DW-DESS-Cones and DWI (r = 0.25, p = 0.38). Concordant hyperintensity/hypointensity was observed between DW-DESS-Cones and DWI in 11/14 lesions. DW-DESS-Cones improved sharpness, distortion, and overall image quality versus DWI. DW-DESS-Cones may be able to eliminate motion artifacts in the breast allowing for investigation of higher degrees of steady-state diffusion weighting. Malignant breast lesions in DW-DESS-Cones demonstrated hyperintensity with respect to surrounding tissue without an injection of contrast. LEVEL OF EVIDENCE: 2. TECHNICAL EFFICACY STAGE: 1.

    View details for DOI 10.1002/jmri.27492

    View details for PubMedID 33382171

  • Comparison of head pose tracking methods for mixed-reality neuronavigation for transcranial magnetic stimulation SPIE Medical Imaging Sathyanarayana, S., Leuze, C., Hargreaves, B., Daniel, B. L., Wetzstein, G., Etkin, A., Bhati, M. T., McNab, J. A. 2020

    View details for DOI 10.1117/12.2547917

  • Enabling In-Bore MRI-Guided Biopsies With Force Feedback IEEE TRANSACTIONS ON HAPTICS Frishman, S., Kight, A., Pirozzi, I., Coffey, M. C., Daniel, B. L., Cutkosky, M. R. 2020; 13 (1): 159–66

    Abstract

    Limited physical access to target organs of patients inside an MRI scanner is a major obstruction to real-time MRI-guided interventions. Traditional teleoperation technologies are incompatible with the MRI environment and although several solutions have been explored, a versatile system that provides high-fidelity haptic feedback and access deep inside the bore remains a challenge. We present a passive and nearly frictionless MRI-compatible hydraulic teleoperator designed for in-bore liver biopsies. We describe the design components, characterize the system transparency, and evaluate the performance with a user study in a laboratory and a clinical setting. The results demonstrate % difference between input and output forces during realistic manipulation. A user study with participants conducting mock needle biopsy tasks indicates that a remote operator performs equally well when using the device as when holding a biopsy needle directly in hand. Additionally, MRI compatibility tests show no reduction in signal-to-noise ratio in the presence of the device.

    View details for DOI 10.1109/TOH.2020.2967375

    View details for Web of Science ID 000521334300023

    View details for PubMedID 31976906

  • A Patient-Specific Mixed-Reality Visualization Tool for Thoracic Surgical Planning. The Annals of thoracic surgery Perkins, S. L., Krajancich, B. n., Jeffrey Yang, C. F., Hargreaves, B. A., Daniel, B. L., Berry, M. F. 2020

    Abstract

    Identifying small lung lesions during minimally invasive thoracic surgery can be challenging. We describe 3D mixed-reality visualization technology that may facilitate non-invasive nodule localization.A software application and medical image processing pipeline were developed for the Microsoft HoloLens to incorporate patient-specific data and provide a mixed-reality tool to explore and manipulate chest anatomy with a custom-designed user interface featuring gesture and voice recognition.A needs assessment between engineering and clinical disciplines identified the potential utility of mixed-reality technology in facilitating safe and effective resection of small lung nodules. Through an iterative process, we developed a prototype employing a wearable headset that allows the user to: (1) view a patient's original preoperative imaging, (2) manipulate a 3D rendering of that patient's chest anatomy including the bronchial, osseus, and vascular structures, and (3) simulate lung deflation and surgical instrument placement.Mixed-reality visualization during surgical planning may facilitate accurate and rapid identification of small lung lesions during minimally invasive surgeries and reduce the need for additional invasive pre-operative localization procedures.

    View details for DOI 10.1016/j.athoracsur.2020.01.060

    View details for PubMedID 32145195

  • Clumped vs non-clumped internal enhancement patterns in linear non-mass enhancement on breast MRI. The British journal of radiology Chen, S. T., Covelli, J. n., Okamoto, S. n., Daniel, B. L., DeMartini, W. B., Ikeda, D. M. 2020: 20201166

    Abstract

    To compare positive predictive values (PPVs) of clumped vs non-clumped (homogenous and heterogeneous) internal enhancement on MRI detected linear non-mass enhancement (NME) on MRI-guided vacuum-assisted breast biopsy (MRI-VABB).With IRB (Institutional Review Board) approval, we retrospectively reviewed 598 lesions undergoing MRI-VABB from January 2015 to April 2018 that showed linear NME. We reviewed the electronic medical records for MRI-VABB pathology, any subsequent surgery and clinical follow-up. The X2 test was performed for univariate analysis.There were 120/598 (20%) linear NME MRI-VABB lesions with clumped (52/120, 43%) vs non-clumped (68/120, 57%) internal enhancement, average size 1.8 cm (range 0.6-7.6 cm). On MRI-VABB, cancer was identified in 22/120 (18%) lesions, ductal carcinoma in situ (DCIS) was found in 18/22 (82%) and invasive cancer in 4 (18%). 3/31 (10%) high-risk lesions upgraded to DCIS at surgery, for a total of 25/120 (21%) malignancies. Malignancy was found in 12/52 (23%) clumped lesions and in 13/68 (19%) of non-clumped lesions that showed heterogeneous (5/13, 38%) or homogenous (8/13, 62%) internal enhancement. The PPV of linear NME with clumped internal enhancement (23.1%) was not significantly different from the PPV of non-clumped linear NME (19.1%) (p = 0.597). The PPV of linear NME lesions <1 cm (33.3%) was not significantly different from the PPV of lesions ≥1 cm (18.6%) (p = 0.157).Linear NME showed malignancy in 21% of our series. Linear NME with clumped or non-clumped internal enhancement patterns, regardless of lesion size, might need to undergo MRI-VABB in appropriate populations.Evaluation of linear NME lesions on breast MRI focuses especially on internal enhancement pattern.

    View details for DOI 10.1259/bjr.20201166

    View details for PubMedID 33332980

  • Application of holographic augmented reality for external approaches to the frontal sinus. International forum of allergy & rhinology Neves, C. A., Vaisbuch, Y. n., Leuze, C. n., McNab, J. A., Daniel, B. n., Blevins, N. H., Hwang, P. H. 2020

    Abstract

    External approaches to the frontal sinus such as osteoplastic flaps are challenging because they require blind entry into the sinus, posing risks of injury to the brain or orbit. Intraoperative computed tomography (CT)-based navigation is the current standard for planning the approach, but still necessitates blind entry into the sinus. The aim of this work was to describe a novel technique for external approaches to the frontal sinus using a holographic augmented reality (AR) application.Our team developed an AR system to create a 3-dimensional (3D) hologram of key anatomical structures, based on CT scans images. Using Magic Leap AR goggles for visualization, the frontal sinus hologram was aligned to the surface anatomy in 6 fresh cadaveric heads' anatomic boundaries, and the boundaries of the frontal sinus were demarcated based on the margins of the fused image. Trephinations and osteoplastic flap approaches were performed. The specimens were re-scanned to assess the accuracy of the osteotomy with respect to the actual frontal sinus perimeter.Registration and surgery were completed successfully in all specimens. Registration required an average of 2 minutes. The postprocedure CT showed a mean difference of 1.4 ± 4.1 mm between the contour of the osteotomy and the contour of the frontal sinus. One surgical complication (posterior table perforation) occurred (16%).We describe proof of concept of a novel technique utilizing AR to enhance external approaches to the frontal sinus. Holographic AR-enhanced surgical navigation holds promise for enhanced visualization of target structures during surgical approaches to the sinuses.

    View details for DOI 10.1002/alr.22546

    View details for PubMedID 32362076

  • RUN-UP: Accelerated multishot diffusion-weighted MRI reconstruction using an unrolled network with U-Net as priors. Magnetic resonance in medicine Hu, Y. n., Xu, Y. n., Tian, Q. n., Chen, F. n., Shi, X. n., Moran, C. J., Daniel, B. L., Hargreaves, B. A. 2020

    Abstract

    To accelerate and improve multishot diffusion-weighted MRI reconstruction using deep learning.An unrolled pipeline containing recurrences of model-based gradient updates and neural networks was introduced for accelerating multishot DWI reconstruction with shot-to-shot phase correction. The network was trained to predict results of jointly reconstructed multidirection data using single-direction data as input. In vivo brain and breast experiments were performed for evaluation.The proposed method achieves a reconstruction time of 0.1 second per image, over 100-fold faster than a shot locally low-rank reconstruction. The resultant image quality is comparable to the target from the joint reconstruction with a peak signal-to-noise ratio of 35.3 dB, a normalized root-mean-square error of 0.0177, and a structural similarity index of 0.944. The proposed method also improves upon the locally low-rank reconstruction (2.9 dB higher peak signal-to-noise ratio, 29% lower normalized root-mean-square error, and 0.037 higher structural similarity index). With training data from the brain, this method also generalizes well to breast diffusion-weighted imaging, and fine-tuning further reduces aliasing artifacts.A proposed data-driven approach enables almost real-time reconstruction with improved image quality, which improves the feasibility of multishot DWI in a wide range of clinical and neuroscientific studies.

    View details for DOI 10.1002/mrm.28446

    View details for PubMedID 32783339

  • Multimodality Hyperpolarized C-13 MRS/PET/Multiparametric MR Imaging for Detection and Image-Guided Biopsy of Prostate Cancer: First Experience in a Canine Prostate Cancer Model MOLECULAR IMAGING AND BIOLOGY Bachawal, S. V., Park, J., Valluru, K. S., Loft, M., Felt, S. A., Vilches-Moure, J. G., Saenz, Y. F., Daniel, B., Iagaru, A., Sonn, G., Cheng, Z., Spielman, D. M., Willmann, J. K. 2019; 21 (5): 861–70
  • Prostate Magnetic Resonance Imaging Interpretation Varies Substantially Across Radiologists EUROPEAN UROLOGY FOCUS Sonn, G. A., Fan, R. E., Ghanouni, P., Wang, N. N., Brooks, J. D., Loening, A. M., Daniel, B. L., To'o, K. J., Thong, A. E., Leppert, J. T. 2019; 5 (4): 592–99
  • Multimodality Hyperpolarized C-13 MRS/PET/Multiparametric MR Imaging for Detection and Image-Guided Biopsy of Prostate Cancer: First Experience in a Canine Prostate Cancer Model. Molecular imaging and biology : MIB : the official publication of the Academy of Molecular Imaging Bachawal, S. V., Park, J. M., Valluru, K. S., Loft, M. D., Felt, S. A., Vilches-Moure, J. G., Saenz, Y. F., Daniel, B., Iagaru, A., Sonn, G., Cheng, Z., Spielman, D. M., Willmann, J. K. 2019

    Abstract

    PURPOSE: To assess whether simultaneous hyperpolarized C-13 magnetic resonance spectroscopy (MRS)/positron emission tomography (PET)/multiparametric magnetic resonance (mpMR) imaging is feasible in an orthotopic canine prostate cancer (PCa) model using a clinical PET/MR system and whether the combined imaging datasets can be fused with transrectal ultrasound (TRUS) in real time for multimodal image fusion-guided targeted biopsy of PCa.PROCEDURES: Institutional Animal Care and Use Committee approval was obtained for this study. Canine prostate adenocarcinoma (Ace-1) cells were orthotopically injected into the prostate of four dogs. Once tumor engraftment was confirmed by TRUS, simultaneous hyperpolarized C-13 MRS of [1-13C]pyruvate, PET (2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG), [68Ga]NODAGA-SCH1), and mpMR (T2W, DWI) imaging was performed using a clinical PET/MR system. Multimodality imaging data sets were then fused with TRUS and image-guided targeted biopsy was performed. Imaging results were then correlated with histological findings.RESULTS: Successful tumor engraftment was histologically confirmed in three of the four dogs (dogs 2, 3, and 4) and simultaneous C-13 MRS/PET/mpMR was feasible in all three. In dog 2, C-13 MRS showed increased lactate signal in the tumor (lactate/totalC=0.47) whereas mpMR did not show any signal changes. In dog 3, [18F]FDG-PET (SUVmean=1.90) and C-13 MRS (lactate/totalC=0.59) showed elevated metabolic activity in the tumor. In dog 4, [18F]FDG (SUVmean=2.43), [68Ga]NODAGA-SCH1 (SUVmean=0.75), and C-13 MRS (Lac/totalC=0.53) showed elevated uptake in tumor compared to control tissue and multimodal image fusion-guided biopsy of the tumor was successfully performed.CONCLUSION: Simultaneous C-13 MRS/PET/mpMR imaging and multimodal image fusion-guided biopsy is feasible in a canine PCa model.

    View details for PubMedID 30793241

  • Motion-robust reconstruction of multishot diffusion-weighted images without phase estimation through locally low-rank regularization MAGNETIC RESONANCE IN MEDICINE Hu, Y., Levine, E. G., Tian, Q., Moran, C. J., Wang, X., Taviani, V., Vasanawala, S. S., Mcnab, J. A., Daniel, B. L., Hargreaves, B. A. 2019; 81 (2): 1181–90

    View details for DOI 10.1002/mrm.27488

    View details for Web of Science ID 000462086300038

  • Breast dispersion imaging using undersampled rapid dynamic contrast-enhanced MRI Shi, L., Srinivasan, S., Hargreaves, B., Daniel, B., Mori, K., Hahn, H. K. SPIE-INT SOC OPTICAL ENGINEERING. 2019

    View details for DOI 10.1117/12.2513059

    View details for Web of Science ID 000491309500085

  • Spatial integration of radiology and pathology images to characterize breast cancer aggressiveness on pre-surgical MRI Rusu, M., Daniel, B., West, R., Angelini, E. D., Landman, B. A. SPIE-INT SOC OPTICAL ENGINEERING. 2019

    View details for DOI 10.1117/12.2512670

    View details for Web of Science ID 000483012700032

  • High-risk lesions diagnosed at MRI-guided vacuum-assisted breast biopsy: imaging characteristics, outcome of surgical excision or imaging follow-up. Breast cancer (Tokyo, Japan) Okamoto, S. n., Chen, S. T., Covelli, J. D., DeMartini, W. B., Daniel, B. L., Ikeda, D. M. 2019

    Abstract

    To evaluate imaging characteristics, outcome of surgical excision or imaging follow-up on high-risk lesions diagnosed at MRI-guided vacuum-assisted breast biopsy (MRI-VABB).We retrospectively reviewed 598 lesions undergoing 9-gauge MRI-VABB from January 2015 to April 2018 to identify high risk breast lesions. We collected patient demographics, breast MRI BI-RADS descriptors, histopathological diagnosis at MRI-VABB and surgical excision, frequency of upgrade to malignancy and imaging follow-up of high-risk lesions. The x2 test and Fisher exact tests were performed for univariate analysis.114 patients with 124/598 findings (20.7%) had high-risk lesions at MRI-VABB, including atypical ductal hyperplasia (ADH) (21/124, 16.9%), lobular neoplasia (40/124, 32.3%), radial scar/complex sclerosing lesion (RS/CSL) (13/124, 10.5%), papillary lesions (49/124, 39.5%), and flat epithelial atypia (FEA) (1/124, 0.8%). 84/124 (67.7%) high-risk lesions were excised. 19/84 (22.6%) were upgraded to malignancy (7 invasive cancer, 12 DCIS). The upgrade rate for ADH and lobular neoplasia was 7/18 (38.9%) and 9/31 (29.0%), respectively. The upgrade rate for RS/CSL was 1/10 (10%). Of the 25 papillary lesions excised, 2 (8%) demonstrated pathologic atypia and were upgraded to DCIS. The other 23 papillary lesions had no upgrade or atypia. Excised high-risk lesions showing upgrade varied from 0.4 to 6 cm in length (mean 1.6 cm). There was a non-significant trend (p = 0.054) between larger lesion and upgrade to malignancy; however, there were no other specific imaging features to predict malignancy upgrade.There were no specific MRI imaging characteristics of high-risk lesions to predict malignancy upgrade. Therefore, surgical excision is recommended for high-risk lesions, especially ADH or lobular neoplasia.

    View details for DOI 10.1007/s12282-019-01032-8

    View details for PubMedID 31838725

  • Multi-shot diffusion-weighted MRI reconstruction with magnitude-based spatial-angular locally low-rank regularization (SPA-LLR). Magnetic resonance in medicine Hu, Y. n., Wang, X. n., Tian, Q. n., Yang, G. n., Daniel, B. n., McNab, J. n., Hargreaves, B. n. 2019

    Abstract

    To resolve the motion-induced phase variations in multi-shot multi-direction diffusion-weighted imaging (DWI) by applying regularization to magnitude images.A nonlinear model was developed to estimate phase and magnitude images separately. A locally low-rank regularization (LLR) term was applied to the magnitude images from all diffusion-encoding directions to exploit the spatial and angular correlation. In vivo experiments with different resolutions and b-values were performed to validate the proposed method.The proposed method significantly reduces the noise level compared to the conventional reconstruction method and achieves submillimeter (0.8mm and 0.9mm isotropic resolutions) DWI with a b-value of 1,000  s / mm 2 and 1-mm isotropic DWI with a b-value of 2,000  s / mm 2 without modification of the sequence.A joint reconstruction method with spatial-angular LLR regularization on magnitude images substantially improves multi-direction DWI reconstruction, simultaneously removes motion-induced phase artifacts, and denoises images.

    View details for DOI 10.1002/mrm.28025

    View details for PubMedID 31593337

  • Motion-robust reconstruction of multishot diffusion-weighted images without phase estimation through locally low-rank regularization. Magnetic resonance in medicine Hu, Y., Levine, E. G., Tian, Q., Moran, C. J., Wang, X., Taviani, V., Vasanawala, S. S., McNab, J. A., Daniel, B. A., Hargreaves, B. L. 2018

    Abstract

    PURPOSE: The goal of this work is to propose a motion robust reconstruction method for diffusion-weighted MRI that resolves shot-to-shot phase mismatches without using phase estimation.METHODS: Assuming that shot-to-shot phase variations are slowly varying, spatial-shot matrices can be formed using a local group of pixels to form columns, in which each column is from a different shot (excitation). A convex model with a locally low-rank constraint on the spatial-shot matrices is proposed. In vivo brain and breast experiments were performed to evaluate the performance of the proposed method.RESULTS: The proposed method shows significant benefits when the motion is severe, such as for breast imaging. Furthermore, the resulting images can be used for reliable phase estimation in the context of phase-estimation-based methods to achieve even higher image quality.CONCLUSION: We introduced the shot-locally low-rank method, a reconstruction technique for multishot diffusion-weighted MRI without explicit phase estimation. In addition, its motion robustness can be beneficial to neuroimaging and body imaging.

    View details for PubMedID 30346058

  • HoloNeedle: Augmented Reality Guidance System for Needle Placement Investigating the Advantages of Three-Dimensional Needle Shape Reconstruction IEEE ROBOTICS AND AUTOMATION LETTERS Lin, M. A., Siu, A. F., Bae, J., Cutkosky, M. R., Daniel, B. L. 2018; 3 (4): 4156–62
  • Magnetic resonance imaging and molecular features associated with tumor-infiltrating lymphocytes in breast cancer. Breast cancer research : BCR Wu, J., Li, X., Teng, X., Rubin, D. L., Napel, S., Daniel, B. L., Li, R. 2018; 20 (1): 101

    Abstract

    BACKGROUND: We sought to investigate associations between dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) features and tumor-infiltrating lymphocytes (TILs) in breast cancer, as well as to study if MRI features are complementary to molecular markers of TILs.METHODS: In this retrospective study, we extracted 17 computational DCE-MRI features to characterize tumor and parenchyma in The Cancer Genome Atlas cohort (n=126). The percentage of stromal TILs was evaluated on H&E-stained histological whole-tumor sections. We first evaluated associations between individual imaging features and TILs. Multiple-hypothesis testing was corrected by the Benjamini-Hochberg method using false discovery rate (FDR). Second, we implemented LASSO (least absolute shrinkage and selection operator) and linear regression nested with tenfold cross-validation to develop an imaging signature for TILs. Next, we built a composite prediction model for TILs by combining imaging signature with molecular features. Finally, we tested the prognostic significance of the TIL model in an independent cohort (I-SPY 1; n=106).RESULTS: Four imaging features were significantly associated with TILs (P<0.05 and FDR<0.2), including tumor volume, cluster shade of signal enhancement ratio (SER), mean SER of tumor-surrounding background parenchymal enhancement (BPE), and proportion of BPE. Among molecular and clinicopathological factors, only cytolytic score was correlated with TILs (rho=0.51; 95% CI, 0.36-0.63; P=1.6E-9). An imaging signature that linearly combines five features showed correlation with TILs (rho=0.40; 95% CI, 0.24-0.54; P=4.2E-6). A composite model combining the imaging signature and cytolytic score improved correlation with TILs (rho=0.62; 95% CI, 0.50-0.72; P=9.7E-15). The composite model successfully distinguished low vs high, intermediate vs high, and low vs intermediate TIL groups, with AUCs of 0.94, 0.76, and 0.79, respectively. During validation (I-SPY 1), the predicted TILs from the imaging signature separated patients into two groups with distinct recurrence-free survival (RFS), with log-rank P=0.042 among triple-negative breast cancer (TNBC). The composite model further improved stratification of patients with distinct RFS (log-rank P=0.0008), where TNBC with no/minimal TILs had a worse prognosis.CONCLUSIONS: Specific MRI features of tumor and parenchyma are associated with TILs in breast cancer, and imaging may play an important role in the evaluation of TILs by providing key complementary information in equivocal cases or situations that are prone to sampling bias.

    View details for PubMedID 30176944

  • Gallium 68 PSMA-11 PET/MR Imaging in Patients with Intermediate- or High-Risk Prostate Cancer. Radiology Park, S. Y., Zacharias, C., Harrison, C., Fan, R. E., Kunder, C., Hatami, N., Giesel, F., Ghanouni, P., Daniel, B., Loening, A. M., Sonn, G. A., Iagaru, A. 2018: 172232

    Abstract

    Purpose To report the results of dual-time-point gallium 68 (68Ga) prostate-specific membrane antigen (PSMA)-11 positron emission tomography (PET)/magnetic resonance (MR) imaging prior to prostatectomy in patients with intermediate- or high-risk cancer. Materials and Methods Thirty-three men who underwent conventional imaging as clinically indicated and who were scheduled for radical prostatectomy with pelvic lymph node dissection were recruited for this study. A mean dose of 4.1 mCi ± 0.7 (151.7 MBq ± 25.9) of 68Ga-PSMA-11 was administered. Whole-body images were acquired starting 41-61 minutes after injection by using a GE SIGNA PET/MR imaging unit, followed by an additional pelvic PET/MR imaging acquisition at 87-125 minutes after injection. PET/MR imaging findings were compared with findings at multiparametric MR imaging (including diffusion-weighted imaging, T2-weighted imaging, and dynamic contrast material-enhanced imaging) and were correlated with results of final whole-mount pathologic examination and pelvic nodal dissection to yield sensitivity and specificity. Dual-time-point metabolic parameters (eg, maximum standardized uptake value [SUVmax]) were compared by using a paired t test and were correlated with clinical and histopathologic variables including prostate-specific antigen level, Gleason score, and tumor volume. Results Prostate cancer was seen at 68Ga-PSMA-11 PET in all 33 patients, whereas multiparametric MR imaging depicted Prostate Imaging Reporting and Data System (PI-RADS) 4 or 5 lesions in 26 patients and PI-RADS 3 lesions in four patients. Focal uptake was seen in the pelvic lymph nodes in five patients. Pathologic examination confirmed prostate cancer in all patients, as well as nodal metastasis in three. All patients with normal pelvic nodes in PET/MR imaging had no metastases at pathologic examination. The accumulation of 68Ga-PSMA-11 increased at later acquisition times, with higher mean SUVmax (15.3 vs 12.3, P < .001). One additional prostate cancer was identified only at delayed imaging. Conclusion This study found that 68Ga-PSMA-11 PET can be used to identify prostate cancer, while MR imaging provides detailed anatomic guidance. Hence, 68Ga-PSMA-11 PET/MR imaging provides valuable diagnostic information and may inform the need for and extent of pelvic node dissection.

    View details for PubMedID 29786490

  • Intratumoral Spatial Heterogeneity at Perfusion MR Imaging Predicts Recurrence-free Survival in Locally Advanced Breast Cancer Treated with Neoadjuvant Chemotherapy. Radiology Wu, J. n., Cao, G. n., Sun, X. n., Lee, J. n., Rubin, D. L., Napel, S. n., Kurian, A. W., Daniel, B. L., Li, R. n. 2018: 172462

    Abstract

    Purpose To characterize intratumoral spatial heterogeneity at perfusion magnetic resonance (MR) imaging and investigate intratumoral heterogeneity as a predictor of recurrence-free survival (RFS) in breast cancer. Materials and Methods In this retrospective study, a discovery cohort (n = 60) and a multicenter validation cohort (n = 186) were analyzed. Each tumor was divided into multiple spatially segregated, phenotypically consistent subregions on the basis of perfusion MR imaging parameters. The authors first defined a multiregional spatial interaction (MSI) matrix and then, based on this matrix, calculated 22 image features. A network strategy was used to integrate all image features and classify patients into different risk groups. The prognostic value of imaging-based stratification was evaluated in relation to clinical-pathologic factors with multivariable Cox regression. Results Three intratumoral subregions with high, intermediate, and low MR perfusion were identified and showed high consistency between the two cohorts. Patients in both cohorts were stratified according to network analysis of multiregional image features regarding RFS (log-rank test, P = .002 for both). Aggressive tumors were associated with a larger volume of the poorly perfused subregion as well as interaction between poorly and moderately perfused subregions and surrounding parenchyma. At multivariable analysis, the proposed MSI-based marker was independently associated with RFS (hazard ratio: 3.42; 95% confidence interval: 1.55, 7.57; P = .002) adjusting for age, estrogen receptor (ER) status, progesterone receptor status, human epidermal growth factor receptor type 2 (HER2) status, tumor volume, and pathologic complete response (pCR). Furthermore, imaging helped stratify patients for RFS within the ER-positive and HER2-positive subgroups (log-rank test, P = .007 and .004) and among patients without pCR after neoadjuvant chemotherapy (log-rank test, P = .003). Conclusion Breast cancer consists of multiple spatially distinct subregions. Imaging heterogeneity is an independent prognostic factor beyond traditional risk predictors.

    View details for PubMedID 29714680

  • Imaging of magnetic ink patterns via off-resonance sensitivity. Magnetic resonance in medicine Perkins, S. L., Daniel, B. L., Hargreaves, B. A. 2018

    Abstract

    Printed magnetic ink creates predictable B0 field perturbations based on printed shape and magnetic susceptibility. This can be exploited for contrast in MR imaging techniques that are sensitized to off-resonance. The purpose of this work was to characterize the susceptibility variations of magnetic ink and demonstrate its application for creating MR-visible skin markings.The magnetic susceptibility of the ink was estimated by comparing acquired and simulated B0 field maps of a custom-built phantom. The phantom was also imaged using a 3D gradient echo sequence with a presaturation pulse tuned to different frequencies, which adjusts the range of suppressed frequencies. Healthy volunteers with a magnetic ink pattern pressed to the skin or magnetic ink temporary flexible adhesives applied to the skin were similarly imaged.The volume-average magnetic susceptibility of the ink was estimated to be 131 ± 3 parts per million across a 1-mm isotropic voxel (13,100 parts per million assuming a 10-μm thickness of printed ink). Adjusting the saturation frequency highlights different off-resonant regions created by the ink patterns; for example, if tuned to suppress fat, fat suppression will fail near the ink due to the off-resonance. This causes magnetic ink skin markings placed over a region with underlying subcutaneous fat to be visible on MR images.Patterns printed with magnetic ink can be imaged and identified with MRI. Temporary flexible skin adhesives printed with magnetic ink have the potential to be used as skin markings that are visible both by eye and on MR images.

    View details for PubMedID 29603366

  • Mixed-reality guidance for brain stimulation treatment of depression Leuze, C., Yang, G., Hargreaves, B., Daniel, B., Mcnab, J. A., IEEE IEEE. 2018: 377–80
  • MR-Compatible Haptic Display of Membrane Puncture in Robot-Assisted Needle Procedures. IEEE transactions on haptics Han, A. K., Bae, J. H., Gregoriou, K. C., Ploch, C. J., Goldman, R. E., Glover, G. H., Daniel, B. L., Cutkosky, M. R. 2018

    Abstract

    Multilayer electroactive polymer films actuate a small hand-held device that can display tool tip forces during MR-guided interventions. The display produces localized skin stretch at the thumb and index fingertips. Tests confirm that the device does not significantly affect MR imaging and produces detectable stimuli in response to forces measured by a biopsy needle instrumented with optical fibers. Tests with human subjects explored robotic and teleoperated paradigms to detect when the needle contacted a membrane embedded at variable depth in a tissue phantom that approximated the properties of porcine liver. In the first case, naive users detected membranes with a 98.9% success rate as the needle was driven at fixed speed. In the second case, users with experience in needle-based procedures controlled the needle insertion and detected membranes embedded in tissue phantoms with a 98% success rate. In the second experiment, some users detected membranes with very light contact forces, but there was greater subject-to-subject variation.

    View details for DOI 10.1109/TOH.2018.2816074

    View details for PubMedID 29993819

  • The impact of computed high b-value images on the diagnostic accuracy of DWI for prostate cancer: A receiver operating characteristics analysis. Scientific reports Ning, P. n., Shi, D. n., Sonn, G. A., Vasanawala, S. S., Loening, A. M., Ghanouni, P. n., Obara, P. n., Shin, L. K., Fan, R. E., Hargreaves, B. A., Daniel, B. L. 2018; 8 (1): 3409

    Abstract

    To evaluate the performance of computed high b value diffusion-weighted images (DWI) in prostate cancer detection. 97 consecutive patients who had undergone multiparametric MRI of the prostate followed by biopsy were reviewed. Five radiologists independently scored 138 lesions on native high b-value images (b = 1200 s/mm2), apparent diffusion coefficient (ADC) maps, and computed high b-value images (contrast equivalent to b = 2000 s/mm2) to compare their diagnostic accuracy. Receiver operating characteristic (ROC) analysis and McNemar's test were performed to assess the relative performance of computed high b value DWI, native high b-value DWI and ADC maps. No significant difference existed in the area under the curve (AUC) for ROCs comparing B1200 (b = 1200 s/mm2) to computed B2000 (c-B2000) in 5 readers. In 4 of 5 readers c-B2000 had significantly increased sensitivity and/or decreased specificity compared to B1200 (McNemar's p < 0.05), at selected thresholds of interpretation. ADC maps were less accurate than B1200 or c-B2000 for 2 of 5 readers (P < 0.05). This study detected no consistent improvement in overall diagnostic accuracy using c-B2000, compared with B1200 images. Readers detected more cancer with c-B2000 images (increased sensitivity) but also more false positive findings (decreased specificity).

    View details for PubMedID 29467370

  • Artifact-reduced imaging of biopsy needles with 2D multispectral imaging. Magnetic resonance in medicine Weber, H. n., Hargreaves, B. A., Daniel, B. L. 2018; 80 (2): 655–61

    Abstract

    Magnetic resonance (MR) guidance for biopsy procedures requires high intrinsic soft-tissue contrast. However, artifacts induced by the metallic needle can reduce its localization and require low-susceptibility needle materials with poorer cutting performance. In a proof of concept, we demonstrate the feasibility of 2D multispectral imaging (2DMSI) for both needle tracking and for needle artifact reduction for more precise needle localization and to enable the usage of needle materials with higher susceptibility.We applied 2DMSI for imaging of MR-compatible biopsy needles, conventional stainless-steel needles, and mixed-material needles and compared it to conventional techniques. In addition, we exploited intrinsic off-resonance information for passive needle tracking.2DMSI achieved a stronger reduction of the needle artifact compared to conventional techniques. For the mixed-material needles, the artifact was reduced to a level below that for MR-compatible needles with conventional imaging. The passive tracking also improved the ability to pinpoint the needle.2DMSI is promising for both needle tracking and artifact-reduced imaging of biopsy needles for a more precise needle localization. 2DMSI may be particularly promising for needles inducing large distortions or for targeting of small lesions. In addition, it may enable the use of needle materials with higher susceptibility and potentially better sampling performance. Magn Reson Med 80:655-661, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

    View details for PubMedID 29285787

    View details for PubMedCentralID PMC5910245

  • Fat-based registration of breast dynamic contrast enhanced water images. Magnetic resonance in medicine Srinivasan, S. n., Hargreaves, B. A., Daniel, B. L. 2018; 79 (4): 2408–14

    Abstract

    In this study, a 3D fat-based deformable registration algorithm was developed for registering dynamic contrast-enhanced breast images.The mutual information similarity measure with free-form deformation motion correction in rapidly enhancing lesions can introduce motion. However, in Dixon-based fat-water separated acquisitions, the nonenhancing fat signal can directly be used to estimate deformable motion, which can be later used to deform the water images. Qualitative comparison of the fat-based registration method to a water-based registration method, and to the unregistered images, was performed by two experienced readers. Quantitative analysis of the registration was evaluated by estimating the mean-squared signal difference on the fat images.Using a scale of 0 (no motion) to 2 ( > 4 voxels of motion), the average image quality score of the fat-based registered images was 0.5 ± 0.6, water-based registration was 0.8 ± 0.8, and the unregistered dataset was 1.6 ± 0.6. The mean-squared-signal-difference metric on the fat images was significantly lower for fat-based registered images compared with both water-based registered and unregistered images.Fat-based registration of breast dynamic contrast-enhanced images is a promising technique for performing deformable motion correction of breast without introducing new motion. Magn Reson Med 79:2408-2414, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

    View details for PubMedID 28745402

  • 3D Cartesian MRI with compressed sensing and variable view sharing using complementary poisson-disc sampling MAGNETIC RESONANCE IN MEDICINE Levine, E., Daniel, B., Vasanawala, S., Hargreaves, B., Saranathan, M. 2017; 77 (5): 1774-1785

    Abstract

    To enable robust, high spatio-temporal-resolution three-dimensional Cartesian MRI using a scheme incorporating a novel variable density random k-space sampling trajectory allowing flexible and retrospective selection of the temporal footprint with compressed sensing (CS).A complementary Poisson-disc k-space sampling trajectory was designed to allow view sharing and varying combinations of reduced view sharing with CS from the same prospective acquisition. These schemes were used for two-point Dixon-based dynamic contrast-enhanced MRI (DCE-MRI) of the breast and abdomen. Results were validated in vivo with a novel approach using variable-flip-angle data, which was retrospectively accelerated using the same methods but offered a ground truth.In breast DCE-MRI, the temporal footprint could be reduced 2.3-fold retrospectively without introducing noticeable artifacts, improving depiction of rapidly enhancing lesions. Further, experiments with variable-flip-angle data showed that reducing view sharing improved accuracy in reconstruction and T1 mapping. In abdominal MRI, 2.3-fold and 3.6-fold reductions in temporal footprint allowed reduced motion artifacts.The complementary-Poisson-disc k-space sampling trajectory allowed a retrospective spatiotemporal resolution tradeoff using CS and view sharing, imparting robustness to motion and contrast enhancement. The technique was also validated using a novel approach of fully acquired variable-flip-angle acquisition. Magn Reson Med, 2016. © 2016 Wiley Periodicals, Inc.

    View details for DOI 10.1002/mrm.26254

    View details for Web of Science ID 000399666400005

    View details for PubMedCentralID PMC5074926

  • Association of morphological and quantitative parameters on dedicated breast PET with the expression status of hormone receptors, HER2 and Ki-67 in breast cancers Miyake, K., Ikeda, D., Lagaru, A., Quon, A., Daniel, B., Lipson, J., Pal, S., Mittra, E., Guo, H., Nakamoto, Y., Nishimatsu, K., Kanao, S., Kataoka, M., Togashi, K. SOC NUCLEAR MEDICINE INC. 2017
  • High-resolution diffusion-weighted imaging of the breast with multiband 2D radiofrequency pulses and a generalized parallel imaging reconstruction MAGNETIC RESONANCE IN MEDICINE Taviani, V., Alley, M. T., Banerjee, S., Nishimura, D. G., Daniel, B. L., Vasanawala, S. S., Hargreaves, B. A. 2017; 77 (1): 209-220

    Abstract

    To develop a technique for high-resolution diffusion-weighted imaging (DWI) and to compare it with standard DWI methods.Multiple in-plane bands of magnetization were simultaneously excited by identically phase modulating each subpulse of a two-dimensional (2D) RF pulse. Several excitations with the same multiband pattern progressively shifted in the phase-encode direction were used to cover the prescribed field of view (FOV). The phase-encoded FOV was limited to the width of a single band to reduce off-resonance-induced distortion and blurring. Parallel imaging (PI) techniques were used to resolve aliasing from the other bands and to combine the different excitations. Following validation in phantoms and healthy volunteers, a preliminary study in breast cancer patients (N=14) was performed to compare the proposed method to conventional DWI with PI and to reduced-FOV DWI.The proposed method gave high-resolution diffusion-weighted images with minimal artifacts at the band intersections. Compared to PI alone, higher phase-encoded FOV-reduction factors and reduced noise amplification were obtained, which translated to higher resolution images than conventional (non-multiband) DWI. The same resolution and image quality achievable over targeted regions using existing reduced-FOV methods was obtained, but the proposed method also enables complete bilateral coverage.We developed an in-plane multiband technique for high-resolution DWI and compared its performance with other standard DWI methods. Magn Reson Med 77:209-220, 2017. © 2016 Wiley Periodicals, Inc.

    View details for DOI 10.1002/mrm.26110

    View details for Web of Science ID 000391038800022

  • Prostate Magnetic Resonance Imaging Interpretation Varies Substantially Across Radiologists. European urology focus Sonn, G. A., Fan, R. E., Ghanouni, P. n., Wang, N. N., Brooks, J. D., Loening, A. M., Daniel, B. L., To'o, K. J., Thong, A. E., Leppert, J. T. 2017

    Abstract

    Multiparametric magnetic resonance imaging (mpMRI) interpreted by experts is a powerful tool for diagnosing prostate cancer. However, the generalizability of published results across radiologists of varying expertise has not been verified.To assess variability in mpMRI reporting and diagnostic accuracy across radiologists of varying experience in routine clinical care.Men who underwent mpMRI and MR-fusion biopsy between 2014-2016. Each MRI scan was read by one of nine radiologists using the Prostate Imaging Reporting and Data System (PIRADS) and was not re-read before biopsy. Biopsy histopathology was the reference standard.Outcomes were the PIRADS score distribution and diagnostic accuracy across nine radiologists. We evaluated the association between age, prostate-specific antigen, PIRADS score, and radiologist in predicting clinically significant cancer (Gleason ≥7) using multivariable logistic regression. We conducted sensitivity analyses for case volume and changes in accuracy over time.We analyzed data for 409 subjects with 503 MRI lesions. While the number of lesions (mean 1.2 lesions/patient) did not differ across radiologists, substantial variation existed in PIRADS distribution and cancer yield. The significant cancer detection rate was 3-27% for PIRADS 3 lesions, 23-65% for PIRADS 4, and 40-80% for PIRADS 5 across radiologists. Some 13-60% of men with a PIRADS score of <3 on MRI harbored clinically significant cancer. The area under the receiver operating characteristic curve varied from 0.69 to 0.81 for detection of clinically significant cancer. PIRADS score (p<0.0001) and radiologist (p=0.042) were independently associated with cancer in multivariable analysis. Neither individual radiologist volume nor study period impacted the results. MRI scans were not retrospectively re-read by all radiologists, precluding measurement of inter-observer agreement.We observed considerable variability in PIRADS score assignment and significant cancer yield across radiologists. We advise internal evaluation of mpMRI accuracy before widespread adoption.We evaluated the interpretation of multiparametric magnetic resonance imaging of the prostate in routine clinical care. Diagnostic accuracy depends on the Prostate Imaging Reporting and Data System score and the radiologist.

    View details for PubMedID 29226826

  • Haptic Feedback of Membrane Puncture with an MR-Compatible Instrumented Needle and Electroactive Polymer Display Bae, J., Han, A., Ploch, C. J., Daniel, B. L., Cutkosky, M. R., Gerling, G., Otaduy, M. A., Ryu, J. H. IEEE. 2017: 54–59
  • A Mixed-Reality System for Breast Surgical Planning Perkins, S. L., Lin, M. A., Srinivasan, S., Wheeler, A. J., Hargreaves, B. A., Daniel, B. L., Broll, W., Regenbrecht, H., Swan, J. E., Bruder, G., Servieres, M., Sugimoto, M. IEEE. 2017: 269–74
  • Impact of Breast Density Legislation on Breast Cancer Risk Assessment and Supplemental Screening: A Survey of 110 Radiology Facilities. breast journal Nayak, L., Miyake, K. K., Leung, J. W., Price, E. R., Liu, Y. I., Joe, B. N., Sickles, E. A., Thomas, W. R., Lipson, J. A., Daniel, B. L., Hargreaves, J., Brenner, R. J., Bassett, L. W., Ojeda-Fournier, H., Lindfors, K. K., Feig, S. A., Ikeda, D. M. 2016; 22 (5): 493-500

    Abstract

    Breast density notification laws, passed in 19 states as of October 2014, mandate that patients be informed of their breast density. The purpose of this study is to assess the impact of this legislation on radiology practices, including performance of breast cancer risk assessment and supplemental screening studies. A 20-question anonymous web-based survey was emailed to radiologists in the Society of Breast Imaging between August 2013 and March 2014. Statistical analysis was performed using Fisher's exact test. Around 121 radiologists from 110 facilities in 34 USA states and 1 Canadian site responded. About 50% (55/110) of facilities had breast density legislation, 36% of facilities (39/109) performed breast cancer risk assessment (one facility did not respond). Risk assessment was performed as a new task in response to density legislation in 40% (6/15) of facilities in states with notification laws. However, there was no significant difference in performing risk assessment between facilities in states with a law and those without (p < 0.831). In anticipation of breast density legislation, 33% (16/48), 6% (3/48), and 6% (3/48) of facilities in states with laws implemented handheld whole breast ultrasound (WBUS), automated WBUS, and tomosynthesis, respectively. The ratio of facilities offering handheld WBUS was significantly higher in states with a law than in states without (p < 0.001). In response to breast density legislation, more than 33% of facilities are offering supplemental screening with WBUS and tomosynthesis, and many are performing formal risk assessment for determining patient management.

    View details for DOI 10.1111/tbj.12624

    View details for PubMedID 27296462

  • Five-year results of a prospective clinical trial investigating accelerated partial breast irradiation using 3D conformal radiotherapy after lumpectomy for early stage breast cancer BREAST Horst, K. C., Fasola, C., Ikeda, D., Daniel, B., Ognibene, G., Goffinet, D. R., Dirbas, F. M. 2016; 28: 178-183

    Abstract

    Accelerated partial breast irradiation (APBI) is emerging as an alternative to whole-breast irradiation. This study presents the results of a prospective trial evaluating 3-dimensional conformal radiotherapy (3D-CRT) to deliver APBI for early-stage breast cancer.Patients with unifocal stage 0-II breast cancer measuring ≤2.5 cm without lymph node involvement were eligible. After lumpectomy, 3D-CRT APBI was delivered to the lumpectomy cavity + margin (34-38.5 Gy in 10 fractions over 5 days).141 patients with 143 breast cancers (2 bilateral) were treated with 3D-CRT APBI. Median age was 60. Median tumor size was 1.1 cm. At a median follow up of 60 months (range, 5-113), the 5-year and 8-year cumulative incidence rate of a true recurrence is 0.9%. The 5-year and 8-year cumulative incidence rates of an elsewhere failure are 2.4% and 4.4%, respectively. The 5-year and 8-year overall survival is 100% and 94%, respectively. Among the 62 patients with follow up >5 years, 95% had excellent/good cosmetic results.Our experience with 3D-CRT APBI demonstrates excellent cosmesis and local control. Longer follow up will be necessary to evaluate long-term efficacy and toxicity of 3D-CRT APBI. CLINICALTRIALS.NCT00185744.

    View details for DOI 10.1016/j.breast.2016.06.001

    View details for Web of Science ID 000379683300027

    View details for PubMedID 27322859

  • 3D Cartesian MRI with compressed sensing and variable view sharing using complementary poisson-disc sampling. Magnetic resonance in medicine Levine, E., Daniel, B., Vasanawala, S., Hargreaves, B., Saranathan, M. 2016: -?

    Abstract

    To enable robust, high spatio-temporal-resolution three-dimensional Cartesian MRI using a scheme incorporating a novel variable density random k-space sampling trajectory allowing flexible and retrospective selection of the temporal footprint with compressed sensing (CS).A complementary Poisson-disc k-space sampling trajectory was designed to allow view sharing and varying combinations of reduced view sharing with CS from the same prospective acquisition. These schemes were used for two-point Dixon-based dynamic contrast-enhanced MRI (DCE-MRI) of the breast and abdomen. Results were validated in vivo with a novel approach using variable-flip-angle data, which was retrospectively accelerated using the same methods but offered a ground truth.In breast DCE-MRI, the temporal footprint could be reduced 2.3-fold retrospectively without introducing noticeable artifacts, improving depiction of rapidly enhancing lesions. Further, experiments with variable-flip-angle data showed that reducing view sharing improved accuracy in reconstruction and T1 mapping. In abdominal MRI, 2.3-fold and 3.6-fold reductions in temporal footprint allowed reduced motion artifacts.The complementary-Poisson-disc k-space sampling trajectory allowed a retrospective spatiotemporal resolution tradeoff using CS and view sharing, imparting robustness to motion and contrast enhancement. The technique was also validated using a novel approach of fully acquired variable-flip-angle acquisition. Magn Reson Med, 2016. © 2016 Wiley Periodicals, Inc.

    View details for DOI 10.1002/mrm.26254

    View details for PubMedID 27097596

    View details for PubMedCentralID PMC5074926

  • Breast Imaging in Women Previously Irradiated for Hodgkin Lymphoma. American journal of clinical oncology Horst, K. C., Fero, K. E., Hancock, S. L., Advani, R. H., Ikeda, D. M., Daniel, B., Rosenberg, S. A., Donaldson, S. S., Hoppe, R. T. 2016; 39 (2): 114-119

    Abstract

    Women treated with mantle irradiation for Hodgkin lymphoma (HL) are at an increased risk of developing breast cancer (BC). Current guidelines recommend screening breast magnetic resonance imaging (MRI) as an adjunct to mammography (M) in these patients. There are limited data, however, as to the impact of breast MRI on cancer detection rates. The aim of the current study is to evaluate the use of breast MRI in survivors of HL treated and followed at a single institution.We retrospectively reviewed 980 female patients treated with mantle irradiation for HL between 1961 and 2008. Records were reviewed to determine age at radiotherapy treatment, radiotherapy dose, breast imaging (including M and breast MRI), biopsy results if applicable, and incidence of BC.A total of 118 patients had breast imaging performed at our institution. Median age at HL diagnosis was 28 years (range, 10 to 69 y). Median radiotherapy dose was 36 Gy (range, 20 to 45 Gy). Seventy-nine patients (67%) underwent M screening only, 1 (1%) breast MRI only, and 38 (32%) both M and breast MRI. Of these 38, 19 (50%) underwent 54 screening MRI studies (range per patient=1 to 8), 13 (34%) underwent preoperative MRI for workup of BC, and 6 (16%) initiated screening MRI of the contralateral breast only after diagnosed with BC. Fifty-nine biopsies were performed: 47 were prompted by suspicious M findings only, 10 by palpable findings on physical examination (PE), and 2 by suspicious breast MRI findings. Of the 47 biopsies prompted by M, 24 revealed malignant disease, whereas 23 proved to be benign. All 10 biopsies performed by palpation were malignant. Both biopsies prompted by MRI findings were benign. With M, there were 34 true-positive findings in 32 patients, 23 false-positive findings, and 1 false-negative finding. With screening MRI, there were 2 false-positive findings, 1 false-negative finding, and no true-positive findings.The role of screening breast MRI in women previously irradiated for HL is evolving. Further education of patients and physicians is important to increase awareness of more sensitive BC screening modalities in this high-risk population. Future studies are necessary to determine the appropriate integration of screening breast MRI into the ongoing follow-up of these women.

    View details for DOI 10.1097/COC.0000000000000025

    View details for PubMedID 24390271

  • PROSTATE CANCER YIELD IN MRI LESIONS VARIES ACROSS RADIOLOGISTS Sonn, G., Fan, R., Li, S., Ghanouni, P., Loening, A., Daniel, B., To'o, K., Gill, H., Chung, B., Brooks, J. ELSEVIER SCIENCE INC. 2016: E42
  • High-resolution diffusion-weighted imaging of the breast with multiband 2D radiofrequency pulses and a generalized parallel imaging reconstruction. Magnetic resonance in medicine Taviani, V., Alley, M. T., Banerjee, S., Nishimura, D. G., Daniel, B. L., Vasanawala, S. S., Hargreaves, B. A. 2016

    Abstract

    To develop a technique for high-resolution diffusion-weighted imaging (DWI) and to compare it with standard DWI methods.Multiple in-plane bands of magnetization were simultaneously excited by identically phase modulating each subpulse of a two-dimensional (2D) RF pulse. Several excitations with the same multiband pattern progressively shifted in the phase-encode direction were used to cover the prescribed field of view (FOV). The phase-encoded FOV was limited to the width of a single band to reduce off-resonance-induced distortion and blurring. Parallel imaging (PI) techniques were used to resolve aliasing from the other bands and to combine the different excitations. Following validation in phantoms and healthy volunteers, a preliminary study in breast cancer patients (N=14) was performed to compare the proposed method to conventional DWI with PI and to reduced-FOV DWI.The proposed method gave high-resolution diffusion-weighted images with minimal artifacts at the band intersections. Compared to PI alone, higher phase-encoded FOV-reduction factors and reduced noise amplification were obtained, which translated to higher resolution images than conventional (non-multiband) DWI. The same resolution and image quality achievable over targeted regions using existing reduced-FOV methods was obtained, but the proposed method also enables complete bilateral coverage.We developed an in-plane multiband technique for high-resolution DWI and compared its performance with other standard DWI methods. Magn Reson Med 77:209-220, 2017. © 2016 Wiley Periodicals, Inc.

    View details for DOI 10.1002/mrm.26110

    View details for PubMedID 26778549

  • Display of Needle Tip Contact Forces for Steering Guidance Bae, J., Ploch, C. J., Lin, M. A., Daniel, B. L., Cutkosky, M. R., Choi, S. M., Kuchenbecker, K. J., Gerling, G. IEEE. 2016: 332–37
  • Assessment of Tumor Morphology on Diffusion- Weighted (DWI) Breast MRI: Diagnostic Value of Reduced Field of View DWI JOURNAL OF MAGNETIC RESONANCE IMAGING Barentsz, M. W., Taviani, V., Chang, J. M., Ikeda, D. M., Miyake, K. K., Banerjee, S., Van den Bosch, M. A., Hargreaves, B. A., Daniel, B. L. 2015; 42 (6): 1656-1665

    Abstract

    To compare the diagnostic value of conventional, bilateral diffusion-weighted imaging (DWI) and high-resolution targeted DWI of known breast lesions.Twenty-one consecutive patients with known breast cancer or suspicious breast lesions were scanned with the conventional bilateral DWI technique, a high-resolution, reduced field of view (rFOV) DWI technique, and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) (3.0 T). We compared bilateral DWI and rFOV DWI quantitatively by measuring the lesions' apparent diffusion coefficient (ADC) values. For qualitative comparison, three dedicated breast radiologists scored image quality and performed lesion interpretation.In a phantom, ADC values were in good agreement with the reference values. Twenty-one patients (30 lesions: 14 invasive carcinomas, 10 benign lesions [of which 5 cysts], 3 high-risk, and 3 in situ carcinomas) were included. Cysts and high-risk lesions were excluded from the quantitative analysis. Quantitatively, both bilateral and rFOV DWI measured lower ADC values in invasive tumors than other lesions. In vivo, rFOV DWI gave lower ADC values than bilateral DWI (1.11 × 10(-3) mm(2) /s vs. 1.24 × 10(-3) mm(2) /s, P = 0.002). Regions of interest (ROIs) were comparable in size between the two techniques (2.90 vs. 2.13 cm(2) , P = 0.721). Qualitatively, all three radiologists scored sharpness of rFOV DWI images as significantly higher than bilateral DWI (P ≤ 0.002). Receiver operating characteristic (ROC) curve analysis showed a higher area under the curve (AUC) in BI-RADS classification for rFOV DWI compared to bilateral DWI (0.71 to 0.93 vs. 0.61 to 0.76, respectively).Tumor morphology can be assessed in more detail with high-resolution DWI (rFOV) than with standard bilateral DWI by providing significantly sharper images. J. MAGN. RESON. IMAGING 2015.

    View details for DOI 10.1002/jmri.24929

    View details for Web of Science ID 000368258100022

  • Assessment of tumor morphology on diffusion-weighted (DWI) breast MRI: Diagnostic value of reduced field of view DWI. Journal of magnetic resonance imaging Barentsz, M. W., Taviani, V., Chang, J. M., Ikeda, D. M., Miyake, K. K., Banerjee, S., Van den Bosch, M. A., Hargreaves, B. A., Daniel, B. L. 2015; 42 (6): 1656-1665

    Abstract

    To compare the diagnostic value of conventional, bilateral diffusion-weighted imaging (DWI) and high-resolution targeted DWI of known breast lesions.Twenty-one consecutive patients with known breast cancer or suspicious breast lesions were scanned with the conventional bilateral DWI technique, a high-resolution, reduced field of view (rFOV) DWI technique, and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) (3.0 T). We compared bilateral DWI and rFOV DWI quantitatively by measuring the lesions' apparent diffusion coefficient (ADC) values. For qualitative comparison, three dedicated breast radiologists scored image quality and performed lesion interpretation.In a phantom, ADC values were in good agreement with the reference values. Twenty-one patients (30 lesions: 14 invasive carcinomas, 10 benign lesions [of which 5 cysts], 3 high-risk, and 3 in situ carcinomas) were included. Cysts and high-risk lesions were excluded from the quantitative analysis. Quantitatively, both bilateral and rFOV DWI measured lower ADC values in invasive tumors than other lesions. In vivo, rFOV DWI gave lower ADC values than bilateral DWI (1.11 × 10(-3) mm(2) /s vs. 1.24 × 10(-3) mm(2) /s, P = 0.002). Regions of interest (ROIs) were comparable in size between the two techniques (2.90 vs. 2.13 cm(2) , P = 0.721). Qualitatively, all three radiologists scored sharpness of rFOV DWI images as significantly higher than bilateral DWI (P ≤ 0.002). Receiver operating characteristic (ROC) curve analysis showed a higher area under the curve (AUC) in BI-RADS classification for rFOV DWI compared to bilateral DWI (0.71 to 0.93 vs. 0.61 to 0.76, respectively).Tumor morphology can be assessed in more detail with high-resolution DWI (rFOV) than with standard bilateral DWI by providing significantly sharper images. J. MAGN. RESON. IMAGING 2015.

    View details for DOI 10.1002/jmri.24929

    View details for PubMedID 25914178

  • Balanced SSFP Dixon imaging with banding-artifact reduction at 3 Tesla MAGNETIC RESONANCE IN MEDICINE Quist, B., Hargreaves, B. A., Daniel, B. L., Saranathan, M. 2015; 74 (3): 706-715

    Abstract

    To develop a three-dimensional (3D) balanced steady-state free-precession (bSSFP) two-point Dixon method with banding-artifact suppression to offer robust high-resolution 3D bright-fluid imaging.A complex sum reconstruction that combines phase-cycled bSSFP images acquired at specific echo times for robust fat/water separation without banding was investigated and compared with a magnitude-based method. Bloch simulations using both single-peak and multiple-peak fat models were performed to predict the performance of these methods for a wide range of echo times and repetition times. The quality and degree of fat/water separation was evaluated in both simulations and using in vivo imaging.Simulations predicted that both effective banding-artifact suppression and substantial improvements in fat/water separation are possible at echo times that are different from conventional echo times, enabling improved spatial resolution. Comparisons between various echo times and repetition times in vivo validated the improved fat/water separation and effective banding-artifact removal predicted by the simulations.The proposed complex sum Dixon 3D bSSFP method is able to effectively separate fat and water at different sets of echo times, while removing banding-artifacts, providing a fast, high-resolution, T2 -like sequence without blurring. Magn Reson Med, 2014. © 2014 Wiley Periodicals, Inc.

    View details for DOI 10.1002/mrm.25449

    View details for Web of Science ID 000360222900012

  • Impact of breast density notification laws on radiology practices: A survey of 110 radiology facilities Nayak, L., Miyake, K. K., Liu, Y., Thomas, W. R., Sickles, E. A., Joe, B. N., Lindfors, K., Brenner, R. J., Feig, S., Bassett, L. W., Leung, J. W., Ojeda-Fournier, H., Hargreaves, J., Price, E., Lipson, J. A., Kurian, A. W., Love, E., Walgenbach, D. D., Ryan, L., Durbin, M., Daniel, B. L., Garcia, L., Ikeda, D. M. AMER ASSOC CANCER RESEARCH. 2015
  • Rim Sign in Breast Lesions on Diffusion-Weighted Magnetic Resonance Imaging: Diagnostic Accuracy and Clinical Usefulness JOURNAL OF MAGNETIC RESONANCE IMAGING Kang, B. J., Lipson, J. A., Planey, K. R., Zackrisson, S., Ikeda, D. M., Kao, J., Pal, S., Moran, C. J., Daniel, B. L. 2015; 41 (3): 616-623

    Abstract

    To investigate the diagnostic accuracy and clinical usefulness of the rim sign in breast lesions observed in diffusion-weighted magnetic resonance imaging (DWI).The magnetic resonance imaging (MRI) findings of 98 pathologically confirmed lesions (62 malignant and 36 benign) in 84 patients were included. Five breast radiologists were asked to independently review the breast MRI results, to grade the degree of high peripheral signal, the "rim sign," in the DWI, and to confirm the mean apparent diffusion coefficient (ADCmean ) values. We analyzed the diagnostic accuracy and compared the consensus (when ≥4 of 5 independent reviewers agreed) results of the rim sign with the ADCmean values. Additionally, we evaluated the correlation between the dynamic contrast-enhanced (DCE)-MRI morphologic appearance and DWI rim sign.According to the consensus results, the rim sign in DWI was observed on 59.7% of malignant lesions and 19.4% of benign lesions. The sensitivity, specificity, and area under the curve (AUC) value for the rim sign in DWI were 59.7%, 80.6%, and 0.701, respectively. The sensitivity, specificity, and AUC value for the ADCmean value (criteria ≤1.46 × 10(-3) mm(2) /sec) were 82.3%, 63.9%, and 0.731, respectively. Based on consensus, no correlation was observed between the DCE-MRI and DWI rim signs.In DWI, a high-signal rim is a valuable morphological feature for improving specificity in DWI.J. Magn. Reson. Imaging 2014. © 2014 Wiley Periodicals, Inc.

    View details for DOI 10.1002/jmri.24617

    View details for Web of Science ID 000349967700006

    View details for PubMedID 24585455

  • A Passive Parallel Master-Slave Mechanism for Magnetic Resonance Imaging-Guided Interventions. Journal of medical devices Elayaperumal, S., Cutkosky, M. R., Renaud, P., Daniel, B. L. 2015; 9 (1): 0110081–1100811

    Abstract

    A passive, parallel master-slave mechanism is presented for magnetic resonance imaging (MRI)-guided interventions in the pelvis. The mechanism allows a physician to stand outside the MRI scanner while manipulating a needle inside the bore and, unlike a powered robot, does not place actuators in proximity to the patient. The manipulator combines two parallel mechanisms based on the Delta robot architecture. The mechanism also includes a two-axis gimbal to allow for tool angulation, giving a total of five degrees of freedom so that the physician can insert and steer a needle using continuous natural arm and wrist movements, unlike simple needle guides. The need for access between the patient's legs and within the MRI scanner leads to an unusual asymmetric design in which the sliding prismatic joints form the vertices of an isosceles triangle. Kinematic analysis shows that the dexterity index of this design is improved over the desired workspace, as compared to an equilateral design. The analysis is extended to estimate the effect of friction and model the input:output force transmission. Prototypes, with final dimensions selected for transperineal prostate interventions, showed force transmission behavior as predicted by simulation, and easily withstood maximum forces required for tool insertion.

    View details for PubMedID 25729467

  • A Passive Parallel Master-Slave Mechanism for Magnetic Resonance Imaging-Guided Interventions JOURNAL OF MEDICAL DEVICES-TRANSACTIONS OF THE ASME Elayaperumal, S., Cutkosky, M. R., Renaud, P., Daniel, B. L. 2015; 9 (1)

    View details for DOI 10.1115/1.4028944

    View details for Web of Science ID 000351642500009

  • Design of an Optically Controlled MR-Compatible Active Needle IEEE TRANSACTIONS ON ROBOTICS Ryu, S. C., Quek, Z. F., Koh, J., Renaud, P., Black, R. J., Moslehi, B., Daniel, B. L., Cho, K., Cutkosky, M. R. 2015; 31 (1): 1-11

    Abstract

    An active needle is proposed for the development of magnetic resonance imaging (MRI)-guided percutaneous procedures. The needle uses a low-transition-temperature shape memory alloy (LT SMA) wire actuator to produce bending in the distal section of the needle. Actuation is achieved with internal optical heating using laser light transported via optical fibers and side coupled to the LT SMA. A prototype, with a size equivalent to a standard 16-gauge biopsy needle, exhibits significant bending, with a tip deflection of more than 14° in air and 5° in hard tissue. A single-ended optical sensor with a gold-coated tip is developed to measure the curvature independently of temperature. The experimental results in tissue phantoms show that human tissue causes fast heat dissipation from the wire actuator; however, the active needle can compensate for typical targeting errors during prostate biopsy.

    View details for DOI 10.1109/TRO.2014.2367351

    View details for Web of Science ID 000352057900001

    View details for PubMedCentralID PMC4620588

  • Design of an Optically Controlled MR-Compatible Active Needle. IEEE transactions on robotics : a publication of the IEEE Robotics and Automation Society Ryu, S. C., Quek, Z. F., Koh, J. S., Renaud, P. n., Black, R. J., Moslehi, B. n., Daniel, B. L., Cho, K. J., Cutkosky, M. R. 2015; 31 (1): 1–11

    Abstract

    An active needle is proposed for the development of magnetic resonance imaging (MRI)-guided percutaneous procedures. The needle uses a low-transition-temperature shape memory alloy (LT SMA) wire actuator to produce bending in the distal section of the needle. Actuation is achieved with internal optical heating using laser light transported via optical fibers and side coupled to the LT SMA. A prototype, with a size equivalent to a standard 16-gauge biopsy needle, exhibits significant bending, with a tip deflection of more than 14° in air and 5° in hard tissue. A single-ended optical sensor with a gold-coated tip is developed to measure the curvature independently of temperature. The experimental results in tissue phantoms show that human tissue causes fast heat dissipation from the wire actuator; however, the active needle can compensate for typical targeting errors during prostate biopsy.

    View details for PubMedID 26512231

  • Variable Spatiotemporal Resolution Three-Dimensional Dixon Sequence for Rapid Dynamic Contrast-Enhanced Breast MRI JOURNAL OF MAGNETIC RESONANCE IMAGING Saranathan, M., Rettmann, D. W., Hargreaves, B. A., Lipson, J. A., Daniel, B. L. 2014; 40 (6): 1392-?

    Abstract

    To investigate a new variable spatiotemporal resolution dynamic contrast-enhanced (DCE) MRI method termed DIfferential Subsampling with Cartesian Ordering (DISCO), for imaging of breast cancer.DISCO combines variable density, pseudorandom k-space segmentation and two-point Dixon fat-water separation for high spatiotemporal resolution breast DCE MRI. During the contrast wash-in phase, view sharing is used to achieve high temporal resolution. Forty patients referred for breast MRI were imaged, 26 using the proposed DISCO sequence and 14 using a conventional low-spatial-resolution dynamic sequence (VIBRANT-FLEX) on a 3 Tesla scanner. DISCO dynamic images from 14 patients were compared with VIBRANT-FLEX images from 14 other patients. The image quality assessed by radiologist image ranking in a blinded manner, and the temporal characteristics of the two sequences were compared.A spatial resolution of 1.1 × 1.1 × 1.2 mm(3) (160 slices, 28 cm field of view) was achieved with axial bilateral coverage in 120 s. Dynamic images with ∼ 9 s effective temporal resolution were generated during the 2-min contrast wash-in phase. The image quality of DISCO dynamic images ranked significantly higher than low spatial resolution VIBRANT-FLEX images (19.5 versus 9.5, Mann-Whitney U-test P = 0.00914), with no significant differences in the maximum slope of aortic enhancement.DISCO is a promising variable-spatiotemporal-resolution imaging sequence for capturing the dynamics of rapidly enhancing tumors as well as structural features postcontrast. A near 1-mm isotropic spatial resolution was achieved with postcontrast static phase images in 120 s and dynamic phase images acquired in 9 s per phase.

    View details for DOI 10.1002/jmri.24490

    View details for Web of Science ID 000344786200001

    View details for PubMedCentralID PMC4019731

  • Autonomous Real-Time Interventional Scan Plane Control With a 3-D Shape-Sensing Needle IEEE TRANSACTIONS ON MEDICAL IMAGING Elayaperumal, S., Plata, J. C., Holbrook, A. B., Park, Y., Pauly, K. B., Daniel, B. L., Cutkosky, M. R. 2014; 33 (11): 2128-2139

    Abstract

    This study demonstrates real-time scan plane control dependent on three-dimensional needle bending, as measured from magnetic resonance imaging (MRI)-compatible optical strain sensors. A biopsy needle with embedded fiber Bragg grating (FBG) sensors to measure surface strains is used to estimate its full 3-D shape and control the imaging plane of an MR scanner in real-time, based on the needle's estimated profile. The needle and scanner coordinate frames are registered to each other via miniature radio-frequency (RF) tracking coils, and the scan planes autonomously track the needle as it is deflected, keeping its tip in view. A 3-D needle annotation is superimposed over MR-images presented in a 3-D environment with the scanner's frame of reference. Scan planes calculated based on the FBG sensors successfully follow the tip of the needle. Experiments using the FBG sensors and RF coils to track the needle shape and location in real-time had an average root mean square error of 4.2 mm when comparing the estimated shape to the needle profile as seen in high resolution MR images. This positional variance is less than the image artifact caused by the needle in high resolution SPGR (spoiled gradient recalled) images. Optical fiber strain sensors can estimate a needle's profile in real-time and be used for MRI scan plane control to potentially enable faster and more accurate physician response.

    View details for DOI 10.1109/TMI.2014.2332354

    View details for Web of Science ID 000344589200006

    View details for PubMedID 24968093

  • Detection of Membrane Puncture with Haptic Feedback using a Tip-Force Sensing Needle. Proceedings of the ... IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE/RSJ International Conference on Intelligent Robots and Systems Elayaperumal, S., Bae, J. H., Daniel, B. L., Cutkosky, M. R. 2014; 2014: 3975–81

    Abstract

    This paper presents calibration and user test results of a 3-D tip-force sensing needle with haptic feedback. The needle is a modified MRI-compatible biopsy needle with embedded fiber Bragg grating (FBG) sensors for strain detection. After calibration, the needle is interrogated at 2 kHz, and dynamic forces are displayed remotely with a voice coil actuator. The needle is tested in a single-axis master/slave system, with the voice coil haptic display at the master, and the needle at the slave end. Tissue phantoms with embedded membranes were used to determine the ability of the tip-force sensors to provide real-time haptic feedback as compared to external sensors at the needle base during needle insertion via the master/slave system. Subjects were able to determine the position of the embedded membranes with significantly better accuracy using FBG tip feedback than with base feedback using a commercial force/torque sensor (p = 0.045) or with no added haptic feedback (p = 0.0024).

    View details for PubMedID 26509101

  • Breast magnetic resonance imaging alters patient selection for accelerated partial breast irradiation. American journal of clinical oncology Horst, K. C., Ikeda, D. M., Fero, K. E., Daniel, B. L., Goffinet, D. R., Dirbas, F. M. 2014; 37 (3): 248-254

    Abstract

    OBJECTIVES:: To determine whether pretreatment contrast-enhanced breast magnetic resonance imaging (MRI) alters patient selection for accelerated partial breast irradiation (APBI). MATERIALS AND METHODS:: Women aged 40 years or older with unifocal invasive or intraductal carcinoma ≤2.5 cm on physical examination, mammography, and ultrasound (US) were evaluated with breast MRI before enrollment on an APBI trial using single-fraction intraoperative radiotherapy (IORT) or fractionated 3-dimensional conformal radiotherapy. Abnormal MRI findings were evaluated with US-guided or MRI-guided biopsy. RESULTS:: Between December 2002 and March 2005, 51 women (median age=61 y; range, 40 to 83 y) who met inclusion criteria underwent breast MRI before APBI. MRI demonstrated limited disease in 41 patients (80.4%): 34 received APBI using IORT (22) or 3DCRT (12), whereas 7 elected standard whole-breast radiotherapy. Ten of the 51 patients (19.6%) had indeterminate or suspicious enhancement patterns on MRI. Five of these 10 (9.8% of MRI cohort) underwent US-guided or MRI-guided biopsy revealing normal breast tissue without atypia: 3 were treated with APBI using IORT (5.9% of MRI cohort) and 2 underwent standard breast conservation therapy (3.9% of MRI cohort). The remaining 5 patients (9.8% of MRI cohort) had MRI findings revealing previously unsuspected pectoral fascia involvement (1), multifocal disease (3), or multicentric disease (1): 2 were treated with standard breast conservation therapy, whereas 3 underwent mastectomy without adjuvant radiotherapy. CONCLUSIONS:: Pretreatment breast MRI altered patient selection for APBI by identifying additional disease in 9.8% of the candidates, all of whom fit into the "cautionary" or "unsuitable" categories as defined by the American Society for Radiation Oncology APBI consensus guidelines. The clinical significance of these findings will be clarified with the results of ongoing randomized trials of APBI that do not incorporate breast MRI as part of the selection criteria.

    View details for DOI 10.1097/COC.0b013e318277d7c8

    View details for PubMedID 23275271

  • Breast Magnetic Resonance Imaging Alters Patient Selection for Accelerated Partial Breast Irradiation AMERICAN JOURNAL OF CLINICAL ONCOLOGY-CANCER CLINICAL TRIALS Horst, K. C., Ikeda, D. M., Fero, K. E., Daniel, B. L., Goffinet, D. R., Dirbas, F. M. 2014; 37 (3): 248-254

    Abstract

    OBJECTIVES:: To determine whether pretreatment contrast-enhanced breast magnetic resonance imaging (MRI) alters patient selection for accelerated partial breast irradiation (APBI). MATERIALS AND METHODS:: Women aged 40 years or older with unifocal invasive or intraductal carcinoma ≤2.5 cm on physical examination, mammography, and ultrasound (US) were evaluated with breast MRI before enrollment on an APBI trial using single-fraction intraoperative radiotherapy (IORT) or fractionated 3-dimensional conformal radiotherapy. Abnormal MRI findings were evaluated with US-guided or MRI-guided biopsy. RESULTS:: Between December 2002 and March 2005, 51 women (median age=61 y; range, 40 to 83 y) who met inclusion criteria underwent breast MRI before APBI. MRI demonstrated limited disease in 41 patients (80.4%): 34 received APBI using IORT (22) or 3DCRT (12), whereas 7 elected standard whole-breast radiotherapy. Ten of the 51 patients (19.6%) had indeterminate or suspicious enhancement patterns on MRI. Five of these 10 (9.8% of MRI cohort) underwent US-guided or MRI-guided biopsy revealing normal breast tissue without atypia: 3 were treated with APBI using IORT (5.9% of MRI cohort) and 2 underwent standard breast conservation therapy (3.9% of MRI cohort). The remaining 5 patients (9.8% of MRI cohort) had MRI findings revealing previously unsuspected pectoral fascia involvement (1), multifocal disease (3), or multicentric disease (1): 2 were treated with standard breast conservation therapy, whereas 3 underwent mastectomy without adjuvant radiotherapy. CONCLUSIONS:: Pretreatment breast MRI altered patient selection for APBI by identifying additional disease in 9.8% of the candidates, all of whom fit into the "cautionary" or "unsuitable" categories as defined by the American Society for Radiation Oncology APBI consensus guidelines. The clinical significance of these findings will be clarified with the results of ongoing randomized trials of APBI that do not incorporate breast MRI as part of the selection criteria.

    View details for DOI 10.1097/COC.0b013e318277d7c8

    View details for Web of Science ID 000336958200006

  • High-resolution, three-dimensional diffusion-weighted breast imaging using DESS. Magnetic resonance imaging Granlund, K. L., Staroswiecki, E., Alley, M. T., Daniel, B. L., Hargreaves, B. A. 2014; 32 (4): 330-341

    Abstract

    To evaluate the use of the double-echo steady-state (DESS) sequence for acquiring high-resolution breast images with diffusion and T2 weighting.Phantom scans were used to verify the T2 and diffusion weighting of the DESS sequence. Image distortion was evaluated in volunteers by comparing DESS images and conventional diffusion-weighted images (DWI) to spoiled gradient-echo images. The DESS sequence was added to a standard clinical protocol, and the resulting patient images were used to evaluate overall image quality and image contrast in lesions.The diffusion weighting of the DESS sequence can be easily modulated by changing the spoiler gradient area and flip angle. Radiologists rated DESS images as having higher resolution and less distortion than conventional DWI. Lesion-to-tissue contrast ratios are strongly correlated between DWI and DESS images (R=0.83) and between T2-weighted fast spin-echo and DESS images (R=0.80).The DESS sequence is able to acquire high-resolution 3D diffusion- and T2-weighted images in short scan times, with image quality that facilitates morphological assessment of lesions.

    View details for DOI 10.1016/j.mri.2013.12.014

    View details for PubMedID 24512800

  • Homogenous Fat Suppression for Bilateral Breast Imaging Using Independent Shims MAGNETIC RESONANCE IN MEDICINE Han, M., Cunningham, C. H., Pauly, J. M., Daniel, B. L., Hargreaves, B. A. 2014; 71 (4): 1511-1517

    Abstract

    To demonstrate the capability of incorporating independent shims into a dual-band spectral-spatial excitation and to compare fat suppression between standard global shims and independent shims for in vivo bilateral breast imaging at 1.5T.A dual-band spectral-spatial excitation pulse was designed by interleaving two flyback spectral-spatial pulses, playing one during positive gradient lobes and the other during negative gradient lobes. Each slab was enabled to have an independent spatial offset, spectral offset, and slab-phase modulation by modulating radiofrequency phase, and independent linear shims were incorporated by playing extra shim gradients. Phantom experiments were performed to demonstrate the functionality of the pulse, and in vivo experiments were performed for 10 healthy volunteers to compare fat suppression between standard shims and independent shims.The phantom experiments confirmed that the dual-band pulse can provide independent spectral and spatial offsets and linear shims to the two slabs. Independent shims provided qualitatively more homogeneous fat suppression than standard shims in seven out of 10 subjects, with equivalent fat suppression in two of the other three subjects.Incorporating independent shims into the dual-band spectral-spatial excitation can provide homogeneous fat suppression in bilateral breast imaging.

    View details for DOI 10.1002/mrm.24803

    View details for Web of Science ID 000333040500017

    View details for PubMedID 23821305

    View details for PubMedCentralID PMC4085331

  • 3D T2-Weighted Spin Echo Imaging in the Breast JOURNAL OF MAGNETIC RESONANCE IMAGING Moran, C. J., Hargreaves, B. A., Saranathan, M., Lipson, J. A., Kao, J., Ikeda, D. M., Daniel, B. L. 2014; 39 (2): 332-338

    Abstract

    PURPOSE: To evaluate the performance of 2D versus 3D T2-weighted spin echo imaging in the breast. MATERIALS AND METHODS: 2D and 3D T2-weighted images were acquired in 25 patients as part of a clinically indicated breast magnetic resonance imaging (MRI) exam. Lesion-to-fibroglandular tissue signal ratio was measured in 16 identified lesions. Clarity of lesion morphology was assessed through a blinded review by three radiologists. Instances demonstrating the potential diagnostic contribution of 3D versus 2D T2-weighted imaging in the breast were noted through unblinded review by a fourth radiologist. RESULTS: The lesion-to-fibroglandular tissue signal ratio was well correlated between 2D and 3D T2-weighted images (R(2)  = 0.93). Clarity of lesion morphology was significantly better with 3D T2-weighted imaging for all observers based on a McNemar test (P ≤ 0.02, P ≤ 0.01, P ≤ 0.03). Instances indicating the potential diagnostic contribution of 3D T2-weighted imaging included improved depiction of signal intensity and improved alignment between DCE and T2-weighted findings. CONCLUSION: In this pilot study, 3D T2-weighted imaging provided comparable contrast and improved depiction of lesion morphology in the breast in comparison to 2D T2-weighted imaging. Based on these results further investigation to determine the diagnostic impact of 3D T2-weighted imaging in breast MRI is warranted.J. Magn. Reson. Imaging 2013;00:000-000. © 2013 Wiley Periodicals, Inc.

    View details for DOI 10.1002/jmri.24151

    View details for Web of Science ID 000329753400011

    View details for PubMedID 23596017

  • Detection of Membrane Puncture with Haptic Feedback using a Tip-Force Sensing Needle IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) Elayaperumal, S., Bae, J. H., Daniel, B. L., Cutkosky, M. R. IEEE. 2014: 3975–3981
  • Balanced SSFP Dixon imaging with banding-artifact reduction at 3 Tesla. Magnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine Quist, B. n., Hargreaves, B. A., Daniel, B. L., Saranathan, M. n. 2014

    Abstract

    To develop a three-dimensional (3D) balanced steady-state free-precession (bSSFP) two-point Dixon method with banding-artifact suppression to offer robust high-resolution 3D bright-fluid imaging.A complex sum reconstruction that combines phase-cycled bSSFP images acquired at specific echo times for robust fat/water separation without banding was investigated and compared with a magnitude-based method. Bloch simulations using both single-peak and multiple-peak fat models were performed to predict the performance of these methods for a wide range of echo times and repetition times. The quality and degree of fat/water separation was evaluated in both simulations and using in vivo imaging.Simulations predicted that both effective banding-artifact suppression and substantial improvements in fat/water separation are possible at echo times that are different from conventional echo times, enabling improved spatial resolution. Comparisons between various echo times and repetition times in vivo validated the improved fat/water separation and effective banding-artifact removal predicted by the simulations.The proposed complex sum Dixon 3D bSSFP method is able to effectively separate fat and water at different sets of echo times, while removing banding-artifacts, providing a fast, high-resolution, T2 -like sequence without blurring. Magn Reson Med, 2014. © 2014 Wiley Periodicals, Inc.

    View details for PubMedID 25227766

  • Why Are Patients Noncompliant With Follow-Up Recommendations After MRI-Guided Core Needle Biopsy of Suspicious Breast Lesions? AJR. American journal of roentgenology Thompson, M. O., Lipson, J., Daniel, B., Harrigal, C., Mullarkey, P., Pal, S., Thompson, A. C., Ikeda, D. 2013; 201 (6): 1391-1400

    Abstract

    The objective of this study was to investigate patient and breast MRI characteristics associated with noncompliance with recommended follow-up after MRI-guided core needle biopsy of suspicious breast lesions.A retrospective review was performed of 576 breast lesions biopsied under MRI guidance between 2007 and 2010. Patient follow-up was obtained from the medical record and from contact with referring physicians.Of 415 women who underwent 576 MRI-guided core needle biopsies for suspicious breast lesions, 123 (29.6%) patients representing 154 of 576 (26.7%) lesions were noncompliant with recommended excision or 6-month MRI follow-up. Referring physicians provided information for 63% (97/154) of lesions in noncompliant patients, of which 49.5% (48/97) were followed by mammography instead of excision or MRI. Noncompliance with MRI follow-up was significantly associated with referral for biopsy by outside hospital physicians (odds ratio [OR], 2.40; p = 0.0001) and with referral for screening MRI (1.46; p = 0.093) and biopsy of a focus or foci lesion (1.63; p = 0.088). Among 178 lesions in patients compliant with follow-up MRI after MRI-guided core needle biopsy, 7.9% (14/178) had abnormal follow-up MRI results, half of which (3.9%, 7/178) were found on repeat biopsy to be high-risk or malignant.Institutions performing MRI-guided core biopsies should be aware that patients referred from outside institutions are more likely to be noncompliant with recommended follow-up. Strategies to improve follow-up should include educating patients on the difference between mammography and MRI follow-up.

    View details for DOI 10.2214/AJR.12.10282

    View details for PubMedID 24261382

  • The california breast density information group: a collaborative response to the issues of breast density, breast cancer risk, and breast density notification legislation. Radiology Price, E. R., Hargreaves, J., Lipson, J. A., Sickles, E. A., Brenner, R. J., Lindfors, K. K., Joe, B. N., Leung, J. W., Feig, S. A., Bassett, L. W., Ojeda-Fournier, H., Daniel, B. L., Kurian, A. W., Love, E., Ryan, L., Walgenbach, D. D., Ikeda, D. M. 2013; 269 (3): 887-892

    Abstract

    In anticipation of breast density notification legislation in the state of California, which would require notification of women with heterogeneously and extremely dense breast tissue, a working group of breast imagers and breast cancer risk specialists was formed to provide a common response framework. The California Breast Density Information Group identified key elements and implications of the law, researching scientific evidence needed to develop a robust response. In particular, issues of risk associated with dense breast tissue, masking of cancers by dense tissue on mammograms, and the efficacy, benefits, and harms of supplementary screening tests were studied and consensus reached. National guidelines and peer-reviewed published literature were used to recommend that women with dense breast tissue at screening mammography follow supplemental screening guidelines based on breast cancer risk assessment. The goal of developing educational materials for referring clinicians and patients was reached with the construction of an easily accessible Web site that contains information about breast density, breast cancer risk assessment, and supplementary imaging. This multi-institutional, multidisciplinary approach may be useful for organizations to frame responses as similar legislation is passed across the United States. © RSNA, 2013 Online supplemental material is available for this article.

    View details for DOI 10.1148/radiol.13131217

    View details for PubMedID 24023072

  • Image quality and diagnostic performance of silicone-specific breast MRI. Magnetic resonance imaging Kim, S. H., Lipson, J. A., Moran, C. J., Shimakawa, A., Kuo, J., Ikeda, D. M., Daniel, B. L. 2013; 31 (9): 1472-1478

    Abstract

    To compare the image quality of three techniques and diagnostic performance in detecting implant rupture.The study included 161 implants for the evaluation of image quality, composed of water-saturated short TI inversion recovery (herein called "water-sat STIR"), three-point Dixon techniques (herein called "Dixon"), and short TI inversion recovery fast spin-echo with iterative decomposition of silicone and water using least-squares approximation (herein called "STIR IDEAL") and included 41 implants for the evaluation of diagnostic performance in detecting rupture, composed of water-sat STIR and STIR IDEAL. Six image quality categories were evaluated and three classifications were used: normal implant, possible rupture, and definite rupture.Statistically significant differences were noted for the image quality categories (p<0.001). STIR IDEAL was superior or equal to water-sat STIR in all image quality categories except artifact effects and superior to Dixon in all categories. Water-sat STIR performed the poorest for water suppression uniformity. The sensitivity and specificity in detecting implant rupture of STIR-IDEAL were 81.8 % and 77.8 % and the difference between two techniques was not statistically significant.STIR-IDEAL is a useful silicone-specific imaging technique demonstrating more robust water suppression and equivalent diagnostic accuracy for detecting implant rupture, than water-sat STIR, at the cost of longer scan time and an increase in minor motion artifacts.

    View details for DOI 10.1016/j.mri.2013.05.011

    View details for PubMedID 23895871

  • Simultaneous T-1 and B-1(+) Mapping Using Reference Region Variable Flip Angle Imaging MAGNETIC RESONANCE IN MEDICINE Sung, K., Saranathan, M., Daniel, B. L., Hargreaves, B. A. 2013; 70 (4): 954-961

    Abstract

    To present a new method that can simultaneously and efficiently measure T1 and B1 (+) maps using reference region variable flip angle (RR-VFA) imaging.Assuming T1 relaxation time in a reference region such as fat is well characterized, and the reference region sufficiently covers smoothly varying B1 (+) field inhomogeneity, B1 (+) maps can be measured from VFA images, conventionally used for T1 measurements. Fat-only images from two-point Dixon acquisitions were used to compute B1 (+) maps, and the B1 (+) maps were compared with ones using the double-angle method (DAM) in 22 breast MRI patients at 3T. Additionally, high spatial resolution VFA images were acquired to show T1 measurements with and without the RR-VFA B1 (+) correction in six patients.RR-VFA is able to generate reliable B1 (+) maps, similar to those using the conventional DAM. This simultaneous T1 and B1 (+) mapping can also be used to reduce T1 estimation errors, where T1 maps have more uniform fibroglandular tissue T1 and better depiction of heterogeneous T1 of breast masses.A new method that can measure both T1 and B1 (+) maps based on Dixon VFA images is described, offering improved T1 quantification with no scan time penalty.

    View details for DOI 10.1002/mrm.24904

    View details for Web of Science ID 000325136300007

    View details for PubMedCentralID PMC3923865

  • Defining an optimal role for breast magnetic resonance imaging when evaluating patients otherwise eligible for accelerated partial breast irradiation. Radiotherapy and oncology Horst, K. C., Fero, K. E., Ikeda, D. M., Daniel, B. L., Dirbas, F. M. 2013; 108 (2): 220-225

    Abstract

    BACKGROUND AND PURPOSE: Pre-treatment breast magnetic resonance imaging (MRI) findings in a cohort of women prospectively evaluated for accelerated partial breast irradiation (APBI) are reviewed and characterized to determine the optimal use of MRI in these patients. MATERIALS AND METHODS: Candidates initially deemed eligible for a prospective APBI trial based on physical examination, mammography, and ultrasound (US) were further evaluated with breast MRI before treatment. All abnormal MRI findings were biopsied. RESULTS: Between 2002 and 2011, 180 women who met inclusion criteria for APBI underwent breast MRI prior to treatment (median age=59; range 38-86). 126 tumors (70%) were invasive carcinomas with or without associated DCIS, while 54 (30%) were pure DCIS. Breast MRI confirmed unifocal disease in 109 patients with 111 cancers (60.5% of MRI cohort). Multifocal disease was identified in 19 patients (10.5% of MRI cohort), while multicentric disease was present in 3 patients (1.6% of MRI cohort). Five patients (4%) had an MRI-detected contralateral cancer. False positive MRI findings were seen in 45 patients (25% of MRI cohort). Pre-menopausal patients and patients with tumors >2cm were more likely to have MRI-detected multifocal/multicentric disease. While there was no statistically significant correlation between multifocal/multicentric disease and breast density, tumor histology, grade, ER status, or Her2/Neu expression, numbers in each category were small, suggesting a lack of statistical power to detect differences that may be clinically meaningful. One hundred and fifty-two of the 180 patients (84.4%) successfully completed lumpectomy and APBI, while 6.7% of the cohort underwent mastectomy. CONCLUSIONS: Breast MRI identified additional disease in 12% of APBI candidates. Premenopausal women and patients with tumors >2cm were more likely to have MRI-detected multifocal/multicentric disease.

    View details for DOI 10.1016/j.radonc.2013.01.019

    View details for PubMedID 23597699

  • Location constrained approximate message passing for compressed sensing MRI MAGNETIC RESONANCE IN MEDICINE Sung, K., Daniel, B. L., Hargreaves, B. A. 2013; 70 (2): 370-381

    Abstract

    Iterative thresholding methods have been extensively studied as faster alternatives to convex optimization methods for solving large-sized problems in compressed sensing. A novel iterative thresholding method called LCAMP (Location Constrained Approximate Message Passing) is presented for reducing computational complexity and improving reconstruction accuracy when a nonzero location (or sparse support) constraint can be obtained from view shared images. LCAMP modifies the existing approximate message passing algorithm by replacing the thresholding stage with a location constraint, which avoids adjusting regularization parameters or thresholding levels. This work is first compared with other conventional reconstruction methods using random one-dimention signals and then applied to dynamic contrast-enhanced breast magnetic resonance imaging to demonstrate the excellent reconstruction accuracy (less than 2% absolute difference) and low computation time (5-10 s using Matlab) with highly undersampled three-dimentional data (244 × 128 × 48; overall reduction factor = 10). Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.

    View details for DOI 10.1002/mrm.24468

    View details for Web of Science ID 000322128300010

    View details for PubMedID 23042658

  • Transmit B-1(+) Field Inhomogeneity and T-1 Estimation Errors in Breast DCE-MRI at 3 Tesla JOURNAL OF MAGNETIC RESONANCE IMAGING Sung, K., Daniel, B. L., Hargreaves, B. A. 2013; 38 (2): 454-459

    Abstract

    PURPOSE: To quantify B 1+ variation across the breasts and to evaluate the accuracy of precontrast T(1) estimation with and without B 1+ variation in breast MRI patients at 3 Tesla (T). MATERIALS AND METHODS: B 1+ and variable flip angle (VFA) T(1) mapping were included in our dynamic contrast-enhanced (DCE) breast imaging protocol to study a total of 25 patients on a 3.0T GE MR 750 system. We computed precontrast T(1) relaxation in fat, which we assumed to be consistent across a cohort of breast imaging subjects, with and without compensation for B 1+ variation. The mean and standard deviation of B 1+ and T(1) values were calculated for statistical data analysis. RESULTS: Our measurements showed a consistent B 1+ field difference between the left and right breasts. The left breast has an average 15.4% higher flip angle than the prescribed flip angle, and the right breast has an average 17.6% lower flip angle than the prescribed flip angle. This average 33% flip angle difference, which can be vendor and model specific, creates a 52% T(1) estimation bias in fat between breasts using the VFA T(1) mapping technique. The T(1) variation is reduced to 7% by including B 1+ correction. CONCLUSION: We have shown that severe B 1+ variation over the breasts can cause a substantial error in T(1) estimation between the breasts, in VFA T(1) maps at 3T, but that compensating for these variations can considerably improve accuracy of T(1) measurements, which can directly benefit quantitative breast DCE-MRI at 3T. J. Magn. Reson. Imaging 2012;. © 2012 Wiley Periodicals, Inc.

    View details for DOI 10.1002/jmri.23996

    View details for Web of Science ID 000323205300024

    View details for PubMedID 23292822

    View details for PubMedCentralID PMC3620726

  • Applicators for magnetic resonance-guided ultrasonic ablation of benign prostatic hyperplasia. Investigative radiology Sommer, G., Pauly, K. B., Holbrook, A., Plata, J., Daniel, B., Bouley, D., Gill, H., Prakash, P., Salgaonkar, V., Jones, P., Diederich, C. 2013; 48 (6): 387-394

    Abstract

    The aims of this study were to evaluate in a canine model applicators designed for ablation of human benign prostatic hyperplasia (BPH) in vivo under magnetic resonance imaging (MRI) guidance, including magnetic resonance thermal imaging (MRTI), determine the ability of MRI techniques to visualize ablative changes in prostate, and evaluate the acute and longer term histologic appearances of prostate tissue ablated during these studies.An MRI-compatible transurethral device incorporating a tubular transducer array with dual 120° sectors was used to ablate canine prostate tissue in vivo, in zones similar to regions of human BPH (enlarged transition zones). Magnetic resonance thermal imaging was used for monitoring of ablation in a 3-T environment, and postablation MRIs were performed to determine the visibility of ablated regions. Three canine prostates were ablated in acute studies, and 2 animals were rescanned before killing at 31 days postablation. Acute and chronic appearances of ablated prostate tissue were evaluated histologically and were correlated with the MRTI and postablation MRI scans.It was possible to ablate regions similar in size to enlarged transition zone in human BPH in 6 to 18 minutes. Regions of acute ablation showed a central "heat-fixed" region surrounded by a region of more obvious necrosis with complete disruption of tissue architecture. After 31 days, ablated regions demonstrated complete apparent resorption of ablated tissue with formation of cystic regions containing fluid. The inherent cooling of the urethra using the technique resulted in complete urethral preservation in all cases.Prostatic ablation of zones of size and shape corresponding to human BPH is possible using appropriate transurethral applicators using MRTI, and ablated tissue may be depicted clearly in contrast-enhanced magnetic resonance images. The ability accurately to monitor prostate tissue heating, the apparent resorption of ablated regions over 1 month, and the inherent urethral preservation suggest that the magnetic resonance-guided techniques described are highly promising for the in vivo ablation of symptomatic human BPH.

    View details for DOI 10.1097/RLI.0b013e31827fe91e

    View details for PubMedID 23462673

  • Focal ablation of prostate cancer: four roles for magnetic resonance imaging guidance CANADIAN JOURNAL OF UROLOGY Sommer, G., Bouley, D., Gill, H., Daniel, B., Pauly, K. B., Diederich, C. 2013; 20 (2): 6672-6681

    Abstract

    There is currently a great deal of interest in the possible use of focal therapies for prostate cancer, since such treatments offer the prospect for control or cure of the primary disease with minimal side effects. Many forms of thermal therapy have been proposed for focal ablation of prostate cancer, including laser, high intensity ultrasound and cryotherapy. This review will demonstrate the important roles that magnetic resonance imaging (MRI) guidance can offer to such focal ablation, focusing on the use of high intensity ultrasonic applicators as an example of one promising technique.Transurethral and interstitial high intensity ultrasonic applicators, designed specifically for ablation of prostate tissue were tested extensively in vivo in a canine model. The roles of MRI in positioning the devices, monitoring prostate ablation, and depicting ablated tissue were assessed using appropriate MRI sequences.MRI guidance provides a very effective tool for the positioning of ablative devices in the prostate, and thermal monitoring successfully predicted ablation of prostate tissue when a threshold of 52 ºC was achieved. Contrast enhanced MRI accurately depicted the distribution of ablated prostate tissue, which is resorbed at 30 days.Guidance of thermal therapies for focal ablation of prostate cancer will likely prove critically dependent on MRI functioning in four separate roles. Our studies indicate that in three roles: device positioning; thermal monitoring of prostate ablation; and depiction of ablated prostate tissue, MR techniques are highly accurate and likely to be of great benefit in focal prostate cancer ablation. A fourth critical role, identification of cancer within the gland for targeting of thermal therapy, is more problematic at present, but will likely become practical with further technological advances.

    View details for PubMedID 23587506

  • MR-compatible biopsy needle with enhanced tip force sensing. Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems : World Haptics Conference. World Haptics Conference Elayaperumal, S., Bae, J. H., Christensen, D., Cutkosky, M. R., Daniel, B. L., Costa, J. M., Black, R. J., Faridian, F., Moslehi, B. 2013; 2013: 109–14

    Abstract

    We describe an instrumented biopsy needle that provides physicians the capability to sense interaction forces directly at the tip of the needle's inner stylet. The sensors consist of optical fiber Bragg gratings (FBGs), and are unaffected by electromagnetic fields; hence the needle is suitable for MR-guided procedures. In comparison to previous instrumented needles that measure bending strains, the new design has additional sensors and a series of micro-machined holes at the tip. The holes increase strain sensitivity, especially to axial forces, without significantly reducing the stiffness or strength. A comparison of the dynamic forces measured with the new needle and those obtained using a force/torque sensor at the needle base shows that the enhanced tip sensitivity is particularly noticeable when there is significant friction along the needle sleeve.

    View details for PubMedID 26509189

  • Subject-specific models of susceptibility-induced B0 field variations in breast MRI JOURNAL OF MAGNETIC RESONANCE IMAGING Jordan, C. D., Daniel, B. L., Koch, K. M., Yu, H., Conolly, S., Hargreaves, B. A. 2013; 37 (1): 227-232

    Abstract

    To rapidly calculate and validate subject-specific field maps based on the three-dimensional shape of the bilateral breast volume.Ten healthy female volunteers were scanned at 3 Tesla using a multi-echo sequence that provides water, fat, in-phase, out-of-phase, and field map images. A shape-specific binary mask was automatically generated to calculate a computed field map using a dipole field model. The measured and computed field maps were compared by visualizing the spatial distribution of the difference field map, the mean absolute error, and the 80% distribution widths of frequency histograms.The 10 computed field maps had a mean absolute error of 38 Hz (0.29 ppm) compared with the measured field maps. The average 80% distribution widths for the histograms of all of the computed, measured, and difference field maps are 205 Hz, 233 Hz, and 120 Hz, respectively.The computed field maps had substantial overall agreement with the measured field maps, indicating that breast MRI field maps can be computed based on the air-tissue interfaces. These estimates may provide a predictive model for field variations and thus have the potential to improve applications in breast MRI.

    View details for DOI 10.1002/jmri.23762

    View details for Web of Science ID 000312720000025

    View details for PubMedID 22865658

    View details for PubMedCentralID PMC3492544

  • The California Breast Density Information Group: A Collaborative Response to the Issues of Breast Density, Breast Cancer Risk, and Breast Density Notification Legislation RADIOLOGY Price, E. R., Hargreaves, J., Lipson, J. A., Sickles, E. A., Brenner, R. J., Lindfors, K. K., Joe, B. N., Leung, J. W., Feig, S. A., Bassett, L. W., Daniel, B. L., Kurian, A. W., Love, E., Ryan, L., Walgenbach, D. D., Ikeda, D. M. 2013: 887–92

    Abstract

    In anticipation of breast density notification legislation in the state of California, which would require notification of women with heterogeneously and extremely dense breast tissue, a working group of breast imagers and breast cancer risk specialists was formed to provide a common response framework. The California Breast Density Information Group identified key elements and implications of the law, researching scientific evidence needed to develop a robust response. In particular, issues of risk associated with dense breast tissue, masking of cancers by dense tissue on mammograms, and the efficacy, benefits, and harms of supplementary screening tests were studied and consensus reached. National guidelines and peer-reviewed published literature were used to recommend that women with dense breast tissue at screening mammography follow supplemental screening guidelines based on breast cancer risk assessment. The goal of developing educational materials for referring clinicians and patients was reached with the construction of an easily accessible Web site that contains information about breast density, breast cancer risk assessment, and supplementary imaging. This multi-institutional, multidisciplinary approach may be useful for organizations to frame responses as similar legislation is passed across the United States. © RSNA, 2013 Online supplemental material is available for this article.

  • MR-compatible biopsy needle with enhanced tip force sensing IEEE World Haptics Conference (WHC) Elayaperumal, S., Bae, J. H., Christensen, D., Cutkosky, M. R., Daniel, B. L., Black, R. J., Costa, J. M., Faridian, F., Moslehi, B. IEEE. 2013: 109–114
  • Metals in MR-mammography: how to deal with it? European journal of radiology Hargreaves, B. A., Daniel, B. L. 2012; 81: S56-8

    View details for DOI 10.1016/S0720-048X(12)70021-9

    View details for PubMedID 23083602

  • Accelerated breast MRI with compressed sensing. European journal of radiology Hargreaves, B. A., Saranathan, M., Sung, K., Daniel, B. L. 2012; 81: S54-5

    View details for DOI 10.1016/S0720-048X(12)70020-7

    View details for PubMedID 23083601

  • Breast MRI without gadolinium: utility of 3D DESS, a new 3D diffusion weighted gradient-echo sequence. European journal of radiology Daniel, B. L., Granlund, K. L., Moran, C. J., Alley, M. T., Lipson, J., Ikeda, D. M., Kao, J., Hargreaves, B. A. 2012; 81: S24-6

    View details for DOI 10.1016/S0720-048X(12)70010-4

    View details for PubMedID 23083590

  • High resolution images of the breast. European journal of radiology Moran, C. J., Saranathan, M., Nnewihe, A. N., Granlund, K. L., Alley, M. T., Daniel, B. L., Hargreaves, B. A. 2012; 81: S101-3

    View details for DOI 10.1016/S0720-048X(12)70041-4

    View details for PubMedID 23083546

  • MRI Enhancement Correlates With High Grade Desmoid Tumor of Breast BREAST JOURNAL Kim, M. J., Wapnir, I. L., Ikeda, D. M., Chisholm, K. M., Do, Y., Daniel, B. L. 2012; 18 (4): 374-376

    View details for DOI 10.1111/j.1524-4741.2012.01255.x

    View details for PubMedID 22716922

  • Multiple renal arteries and non-contrast magnetic resonance angiography in transplant renal artery stenosis. Clinical kidney journal Munoz Mendoza, J., Melcher, M. L., Daniel, B., Tan, J. C. 2012; 5 (3): 272-275

    View details for DOI 10.1093/ckj/sfs027

    View details for PubMedID 26069784

  • Toward MR-guided high intensity focused ultrasound for presurgical localization: Focused ultrasound lesions in cadaveric breast tissue JOURNAL OF MAGNETIC RESONANCE IMAGING Bitton, R. R., Kaye, E., Dirbas, F. M., Daniel, B. L., Pauly, K. B. 2012; 35 (5): 1089-1097

    Abstract

    To investigate magnetic resonance image-guided high intensity focused ultrasound (MR-HIFU) as a surgical guide for nonpalpable breast tumors by assessing the palpability of MR-HIFU-created lesions in ex vivo cadaveric breast tissue.MR-HIFU ablations spaced 5 mm apart were made in 18 locations using the ExAblate2000 system. Ablations formed a square perimeter in mixed adipose and fibroglandular tissue. Ablation was monitored using T1-weighted fast spin echo images. MR-acoustic radiation force impulse (MR-ARFI) was used to remotely palpate each ablation location, measuring tissue displacement before and after thermal sonications. Displacement profiles centered at each ablation spot were plotted for comparison. The cadaveric breast was manually palpated to assess stiffness of ablated lesions and dissected for gross examination. This study was repeated on three cadaveric breasts.MR-ARFI showed a collective postablation reduction in peak displacement of 54.8% ([4.41 ± 1.48] μm pre, [1.99 ± 0.82] μm post), and shear wave velocity increase of 65.5% ([10.69 ± 1.60] mm pre, [16.33 ± 3.10] mm post), suggesting tissue became stiffer after the ablation. Manual palpation and dissection of the breast showed increased palpability, a darkening of ablation perimeter, and individual ablations were visible in mixed adipose/fibroglandular tissue.The results of this preliminary study show MR-HIFU has the ability to create palpable lesions in ex vivo cadaveric breast tissue, and may potentially be used to preoperatively localize nonpalpable breast tumors.

    View details for DOI 10.1002/jmri.23529

    View details for PubMedID 22170814

  • An Optical Actuation System and Curvature Sensor for a MR-compatible Active Needle. IEEE International Conference on Robotics and Automation : ICRA : [proceedings]. IEEE International Conference on Robotics and Automation Ryu, S. C., Quek, Z. F., Renaud, P., Black, R. J., Daniel, B. L., Cutkosky, M. R. 2012; 2012: 1589–94

    Abstract

    A side optical actuation method is presented for a slender MR-compatible active needle. The needle includes an active region with a shape memory alloy (SMA) wire actuator, where the wire generates a contraction force when optically heated by a laser delivered though optical fibers, producing needle tip bending. A prototype, with multiple side heating spots, demonstrates twice as fast an initial response compared to fiber tip heating when 0.8 W of optical power is applied. A single-ended optical sensor with a gold reflector is also presented to measure the curvature as a function of optical transmission loss. Preliminary tests with the sensor prototype demonstrate approximately linear response and a repeatable signal, independent of the bending history.

    View details for PubMedID 26509099

  • Intravaginal Gel for Staging of Female Pelvic Cancers-Preliminary Report of Safety, Distention, and Gel-Mucosal Contrast During Magnetic Resonance Examination JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Young, P., Daniel, B., Sommer, G., Kim, B., Herfkens, R. 2012; 36 (2): 253-256

    Abstract

    To more fully outline cervical and vaginal contours and distend the vagina, we have filled the vagina with sterile water-based gel before the magnetic resonance (MR) examination. The technique is similar to that used for defecating MR proctography and other MR examinations, but has not been well described for MR imaging of female pelvic cancer. We present our preliminary clinical experience, including a review of safety imaging characteristics and maintenance of the distention during the examination.

    View details for DOI 10.1097/RCT.0b013e3182483c05

    View details for Web of Science ID 000302141800018

    View details for PubMedID 22446369

  • An Optical Actuation System and Curvature Sensor for a MR-compatible Active Needle IEEE International Conference on Robotics and Automation (ICRA) Ryu, S. C., Quek, Z. F., Renaud, P., Black, R. J., Daniel, B. L., Cutkosky, M. R. IEEE. 2012: 1589–1594
  • High Spatio-Temporal Resolution Dynamic Contrast-Enhnaced MRI using Compressed Sensing Annual Summit and Conference of the Asia-Pacific-Signal-and-Information-Processing-Association (APSIPA) Sung, K., Saranathan, M., Daniel, B. L., Hargreaves, B. A. IEEE. 2012
  • MRI of Frozen Tissue Demonstrates a Phase Shift MAGNETIC RESONANCE IN MEDICINE Lu, A., Daniel, B. L., Kaye, E., Pauly, K. B. 2011; 66 (6): 1582-1589

    Abstract

    While temperature mapping is desired during cryosurgery for prostate cancer treatment, an effective approach for this purpose is still needed. We have demonstrated a phase shift with temperature in our in vivo canine experiments and ex vivo tissue sample experiments within the frozen tissue. The phase shift is much larger (~0.7 °/°C with an echo time of 0.1 ms at 0.5 T) in magnitude than that predicted by conventional proton resonant frequency shift (0.008 °/°C). It shows little dependence on the echo times used and thus is not due to a frequency change, although frequency-dependent phase shift has been observed near the frozen tissue. This phase shift varies monotonically with temperature within the frozen tissue and therefore may be potentially used as a novel temperature mapping approach in cryoablation applications.

    View details for DOI 10.1002/mrm.22953

    View details for Web of Science ID 000297285000012

    View details for PubMedID 21630347

    View details for PubMedCentralID PMC3166360

  • Spontaneous Suburothelial Hemorrhage in Coagulopathic Patients: CT Diagnosis AMERICAN JOURNAL OF ROENTGENOLOGY Gayer, G., Desser, T. S., Hertz, M., Osadchy, A., Daniel, B. L., Zissin, R. 2011; 197 (5): W887-W890

    Abstract

    The objective of our study was to identify and describe the spectrum of CT findings in patients with coagulopathy-induced suburothelial hemorrhage involving the renal collecting system.CT findings of suburothelial hemorrhage are often subtle and are best appreciated on unenhanced CT scans because of the high density of the hemorrhage. After contrast injection, uniformly thickened soft tissue enveloping the collecting system is suggestive of this condition. Clinical information regarding the presence of coagulopathy is essential for the radiologist to entertain this relatively rare diagnosis.

    View details for DOI 10.2214/AJR.11.6474

    View details for Web of Science ID 000296512800013

    View details for PubMedID 22021537

  • MR Imaging-guided Cryoablation for the Treatment of Benign Prostatic Hyperplasia JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Ghanouni, P., Gill, H., Kaye, E., Pauly, K. B., Daniel, B. 2011; 22 (10): 1427-1430

    Abstract

    A patient with benign prostatic hyperplasia presented with chronic lower urinary tract symptoms despite prior surgery and continued medical therapy. Using a magnetic resonance imaging-guided transperineal approach, two cryoprobes were placed into the transition zone of the prostate gland, and two cryoablation freeze-thaw cycles were performed. At 10 weeks after treatment, the frequency of nocturia had decreased from once every 1.5 hours to once per night, urinary peak flow rates had increased from 5.1 mL/s to 10.3 mL/s, and postvoid residual urinary bladder volume had decreased from 187 mL to 58 mL. Improved flow rates and symptoms remained stable 16 weeks after treatment.

    View details for DOI 10.1016/j.jvir.2011.08.010

    View details for PubMedID 21961982

  • Feasibility Study of an Optically Actuated MR-compatible Active Needle. Proceedings of the ... IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE/RSJ International Conference on Intelligent Robots and Systems Ryu, S. C., Renaud, P., Black, R. J., Daniel, B. L., Cutkosky, M. R. 2011; 2011: 2564–69

    Abstract

    An active needle is proposed for the development of MRI guided percutaneous procedures. The needle uses internal laser heating, conducted via optical fibers, of a shape memory alloy (SMA) actuator to produce bending in the distal section of the needle. Active bending of the needle as it is inserted allows it to reach small targets while overcoming the effects of interactions with surrounding tissue, which can otherwise deflect the needle away from its ideal path. The active section is designed to bend preferentially in one direction under actuation, and is also made from SMA for its combination of MR and bio-compatibility and its superelastic bending properties. A prototype, with a size equivalent to standard 16G biopsy needle, exhibits significant bending with a tip rotation of more than 10°. A numerical analysis and experiments provide information concerning the required amount of heating and guidance for design of efficient optical heating systems.

    View details for PubMedID 26509100

  • MRI-Guided Ablation of Breast Cancer: Where Do We Stand Today? JOURNAL OF MAGNETIC RESONANCE IMAGING Postma, E. L., van Hillegersberg, R., Daniel, B. L., Merckel, L. G., Verkooijen, H. M., van den Bosch, M. A. 2011; 34 (2): 254-261

    Abstract

    The treatment of patients with localized breast cancer has changed considerably over the past few decades. The next challenge is to use image-guided minimally invasive tumor ablation techniques. The fact that MRI is the most accurate imaging modality for visualization and delineation of breast tumor margins in three dimensions and provides MRI-based temperature mapping, makes it particularly applicable for monitoring during minimally invasive ablation techniques. The overall result of the studies performed on MRI-guided minimally invasive tumor ablation studies are varying, with reported total tumor ablation rates ranging between 20% and 100%. Strict selection of patients, consensus on the treatment zone margin and optimization of MR-imaging, should make MRI-guided breast cancer tumor ablation a useful tool in clinical practice.

    View details for DOI 10.1002/jmri.22599

    View details for Web of Science ID 000293361300001

    View details for PubMedID 21780220

  • Custom-Fitted 16-Channel Bilateral Breast Coil for Bidirectional Parallel Imaging MAGNETIC RESONANCE IN MEDICINE Nnewihe, A. N., Grafendorfer, T., Daniel, B. L., Calderon, P., Alley, M. T., Robb, F., Hargreaves, B. A. 2011; 66 (1): 281-289

    Abstract

    A 16-channel receive-only, closely fitted array coil is described and tested in vivo for bilateral breast imaging at 3 T. The primary purpose of this coil is to provide high signal-to-noise ratio and parallel imaging acceleration in two directions for breast MRI. Circular coil elements (7.5-cm diameter) were placed on a closed "cup-shaped" platform, and nearest neighbor coils were decoupled through geometric overlap. Comparisons were made between the 16-channel custom coil and a commercially available 8-channel coil. SENSitivity Encoding (SENSE) parallel imaging noise amplification (g-factor) was evaluated in phantom scans. In healthy volunteers, we compared signal-to-noise ratio, parallel imaging in one and two directions, Autocalibrating Reconstruction for Cartesian sampling (ARC) g-factor, and high spatial resolution imaging. When compared with a commercially available 8-channel coil, the 16-channel custom coil shows 3.6× higher mean signal-to-noise ratio in the breast and higher quality accelerated images. In patients, the 16-channel custom coil has facilitated high-quality, high-resolution images with bidirectional acceleration of R = 6.3.

    View details for DOI 10.1002/mrm.22771

    View details for Web of Science ID 000292425100034

    View details for PubMedID 21287593

    View details for PubMedCentralID PMC3128917

  • MR Water Quantitative Priors Improves the Accuracy of Optical Breast Imaging IEEE TRANSACTIONS ON MEDICAL IMAGING Carpenter, C. M., Pogue, B. W., Jiang, S., Wang, J., Hargreaves, B. A., Rakow-Penner, R., Daniel, B. L., Paulsen, K. D. 2011; 30 (1): 159-168

    Abstract

    Magnetic resonance (MR) guided optical breast imaging is a promising modality to improve the specificity of breast imaging, because it provides high-resolution quantitative maps of total hemoglobin, oxygen saturation, water content, and optical scattering. These properties have been shown to distinguish malignant from benign lesions. However, the optical detection hardware required for deep tissue imaging has poor spectral sensitivity which limits accurate water quantification; this reduces the accuracy of hemoglobin quantification. We present a methodology to improve optical quantification by utilizing the ability of Dixon MR imaging to quantitatively estimate water and fat; this technique effectively reduces optical crosstalk between water and oxyhemoglobin. The techniques described in this paper reduce hemoglobin quantification error by as much as 38%, as shown in a numerical phantom, and an experimental phantom. Error is reduced by as much 20% when imperfect MR water quantification is given. These techniques may also increase contrast between diseased and normal tissue, as shown in breast tissue in vivo. It is also shown that using these techniques may permit fewer wavelengths to be used with similar quantitative accuracy, enabling higher temporal resolution. In addition, it is shown that these techniques can improve the ability of MRI to quantify water in the presence of bias in the Dixon water/fat separation.

    View details for DOI 10.1109/TMI.2010.2071394

    View details for Web of Science ID 000285844900014

    View details for PubMedID 20813635

    View details for PubMedCentralID PMC3774063

  • Feasibility Study of an Optically Actuated MR-compatible Active Needle IEEE/RSJ International Conference on Intelligent Robots and Systems Ryu, S. C., Renaud, P., Black, R. J., Daniel, B. L., Cutkosky, M. R. IEEE. 2011
  • Real-Time Estimation of 3-D Needle Shape and Deflection for MRI-Guided Interventions IEEE-ASME TRANSACTIONS ON MECHATRONICS Park, Y., Elayaperumal, S., Daniel, B., Ryu, S. C., Shin, M., Savall, J., Black, R. J., Moslehi, B., Cutkosky, M. R. 2010; 15 (6): 906-915

    Abstract

    We describe a MRI-compatible biopsy needle instrumented with optical fiber Bragg gratings for measuring bending deflections of the needle as it is inserted into tissues. During procedures, such as diagnostic biopsies and localized treatments, it is useful to track any tool deviation from the planned trajectory to minimize positioning errors and procedural complications. The goal is to display tool deflections in real time, with greater bandwidth and accuracy than when viewing the tool in MR images. A standard 18 ga × 15 cm inner needle is prepared using a fixture, and 350-μm-deep grooves are created along its length. Optical fibers are embedded in the grooves. Two sets of sensors, located at different points along the needle, provide an estimate of the bent profile, as well as temperature compensation. Tests of the needle in a water bath showed that it produced no adverse imaging artifacts when used with the MR scanner.

    View details for DOI 10.1109/TMECH.2010.2080360

    View details for Web of Science ID 000285361700010

    View details for PubMedCentralID PMC4577522

  • Respiratory Navigated Free Breathing 3D Spoiled Gradient-Recalled Echo Sequence for Contrast-Enhanced Examination of the Liver: Diagnostic Utility and Comparison With Free Breathing and Breath-Hold Conventional Examinations AMERICAN JOURNAL OF ROENTGENOLOGY Young, P. M., Brau, A. C., Iwadate, Y., Vasanawala, S., Daniel, B. L., Tamrazi, A., Herfkens, R. J. 2010; 195 (3): 687-691

    Abstract

    The purpose of our study was to evaluate image quality in a 3D spoiled gradient-recalled echo (SPGR) sequence that was modified to incorporate respiratory navigation to limit the deleterious effects of respiratory motion and to compare it with conventional scanning during breath-holding and free breathing.Respiratory navigation of 3D SPGR sequences is technically feasible, and image quality is modestly improved over free breathing acquisitions using conventional 3D SPGR sequences. This may represent a promising imaging alternative for patients who cannot hold their breath.

    View details for DOI 10.2214/AJR.09.3892

    View details for Web of Science ID 000281180500022

    View details for PubMedID 20729447

  • Detecting Blood Oxygen Level-Dependent (BOLD) Contrast in the Breast JOURNAL OF MAGNETIC RESONANCE IMAGING Rakow-Penner, R., Daniel, B., Glover, G. H. 2010; 32 (1): 120-129

    Abstract

    To develop a robust technique for detecting blood oxygenation level-dependent (BOLD) contrast in the human breast and to evaluate the signal in healthy and malignant breast.The design of this study focused on determining the optimal pulse sequence and stimulus for detecting BOLD contrast in the breast. For this study a single-shot fast spin echo (SSFSE) sequence was compared to a gradient echo (GRE) pulse sequence. Also, several hyperoxic stimuli were tested on 15 healthy volunteers to determine the best stimulus for inducing BOLD contrast in the breast: air interleaved with carbogen (95% O(2), 5% CO(2)), air interleaved with oxygen, and oxygen interleaved with carbogen. The stimulus with the most consistent results among the healthy population was tested on three breast cancer patients.An SSFSE pulse sequence produced improved BOLD contrast results in the breast compared to a GRE pulse sequence. Oxygen interleaved with carbogen yielded the most consistent results in the healthy population. BOLD contrast in healthy glandular breast tissue positively correlates with carbogen and malignant tissue mostly negatively correlates to carbogen.BOLD contrast can consistently be detected in the breast using a robust protocol. This methodology may be used in the future as a noninvasive method for evaluating tumor oxygenation.

    View details for DOI 10.1002/jmri.22227

    View details for Web of Science ID 000279439600015

    View details for PubMedID 20578018

  • Freehand MRI-Guided Preoperative Needle Localization of Breast Lesions After MRI-Guided Vacuum-Assisted Core Needle Biopsy Without Marker Placement JOURNAL OF MAGNETIC RESONANCE IMAGING van de Ven, S. M., Lin, M. C., Daniel, B. L., Sareen, P., Lipson, J. A., Pal, S., Dirbas, F. M., Ikeda, D. M. 2010; 32 (1): 101-109

    Abstract

    To evaluate the feasibility of magnetic resonance imaging (MRI)-guided preoperative needle localization (PNL) of breast lesions previously sampled by MRI-guided vacuum-assisted core needle biopsy (VACNB) without marker placement.We reviewed 15 women with 16 breast lesions undergoing MRI-guided VACNB without marker placement who subsequently underwent MRI-guided PNL, both on an open 0.5T magnet using freehand techniques. Mammograms and specimen radiographs were rated for lesion visibility; MRI images were rated for lesion visibility and hematoma formation. Imaging findings were correlated with pathology.The average prebiopsy lesion size was 16 mm (range 4-50 mm) with 13/16 lesions located in mammographically dense breasts. Eight hematomas formed during VACNB (average size 13 mm, range 8-19 mm). PNL was performed for VACNB pathologies of cancer (5), high-risk lesions (5), or benign but discordant findings (6) at 2-78 days following VACNB. PNL targeted the lesion (2), hematoma (4), or surrounding breast architecture (10). Wire placement was successful in all 16 lesions. Final pathology showed six cancers, five high-risk lesions, and five benign findings.MRI-guided PNL is successful in removing lesions that have previously undergone VACNB without marker placement by targeting the residual lesion, hematoma, or surrounding breast architecture, even in mammographically dense breasts.

    View details for DOI 10.1002/jmri.22148

    View details for Web of Science ID 000279439600013

    View details for PubMedID 20575077

  • Inspired gas-induced vascular change in tumors with magnetic-resonance-guided near-infrared imaging: human breast pilot study JOURNAL OF BIOMEDICAL OPTICS Carpenter, C. M., Rakow-Penner, R., Jiang, S., Daniel, B. L., Pogue, B. W., Glover, G. H., Paulsen, K. D. 2010; 15 (3)

    Abstract

    This study investigates differences in the response of breast tumor tissue versus healthy fibroglandular tissue to inspired gases. Cycles of carbogen and oxygen gas are administered while measuring the changes with magnetic-resonance-guided near-infrared imaging in a pilot study of breast cancers. For two patients, analyses are performed with cross-correlation techniques, which measure the strength of hemodynamic modulation. The results show that the overall vasoresponse, indicated by total hemoglobin, of healthy tissue has approximately a 72% and 41% greater correlation to the gas stimulus than the tumor region, in two patients respectively, when background physiological changes are controlled. These data support the hypothesis that tumor vasculature has a poorly functioning vasodilatory mechanism, most likely caused by dysfunctional smooth muscle cells lining the vasculature. This study presents a methodology to quantitatively analyze inspired gas changes in human breast tumors, and demonstrates this technique in a pilot patient population.

    View details for DOI 10.1117/1.3430729

    View details for Web of Science ID 000280642900041

    View details for PubMedID 20615028

    View details for PubMedCentralID PMC2887914

  • Consistency of Signal Intensity and T2*in Frozen Ex Vivo Heart Muscle, Kidney, and Liver Tissue JOURNAL OF MAGNETIC RESONANCE IMAGING Kaye, E. A., Josan, S., Lu, A., Rosenberg, J., Daniel, B. L., Pauly, K. B. 2010; 31 (3): 719-724

    Abstract

    To investigate tissue dependence of the MRI-based thermometry in frozen tissue by quantification and comparison of signal intensity and T2* of ex vivo frozen tissue of three different types: heart muscle, kidney, and liver.Tissue samples were frozen and imaged on a 0.5 Tesla MRI scanner with ultrashort echo time (UTE) sequence. Signal intensity and T2* were determined as the temperature of the tissue samples was decreased from room temperature to approximately -40 degrees C. Statistical analysis was performed for (-20 degrees C, -5 degrees C) temperature interval.The findings of this study demonstrate that signal intensity and T2* are consistent across three types of tissue for (-20 degrees C, -5 degrees C) temperature interval.Both parameters can be used to calculate a single temperature calibration curve for all three types of tissue and potentially in the future serve as a foundation for tissue-independent MRI-based thermometry.

    View details for DOI 10.1002/jmri.22029

    View details for PubMedID 20187218

  • Real-Time Estimation of 3-D Needle Shape and Deflection for MRI-Guided Interventions. IEEE/ASME transactions on mechatronics : a joint publication of the IEEE Industrial Electronics Society and the ASME Dynamic Systems and Control Division Park, Y. L., Elayaperumal, S. n., Daniel, B. n., Ryu, S. C., Shin, M. n., Savall, J. n., Black, R. J., Moslehi, B. n., Cutkosky, M. R. 2010; 15 (6): 906–15

    Abstract

    We describe a MRI-compatible biopsy needle instrumented with optical fiber Bragg gratings for measuring bending deflections of the needle as it is inserted into tissues. During procedures, such as diagnostic biopsies and localized treatments, it is useful to track any tool deviation from the planned trajectory to minimize positioning errors and procedural complications. The goal is to display tool deflections in real time, with greater bandwidth and accuracy than when viewing the tool in MR images. A standard 18 ga × 15 cm inner needle is prepared using a fixture, and 350-μm-deep grooves are created along its length. Optical fibers are embedded in the grooves. Two sets of sensors, located at different points along the needle, provide an estimate of the bent profile, as well as temperature compensation. Tests of the needle in a water bath showed that it produced no adverse imaging artifacts when used with the MR scanner.

    View details for PubMedID 26405428

  • Independent Slab-Phase Modulation Combined With Parallel Imaging in Bilateral Breast MRI MAGNETIC RESONANCE IN MEDICINE Han, M., Beatty, P. J., Daniel, B. L., Hargreaves, B. A. 2009; 62 (5): 1221-1231

    Abstract

    Independent slab-phase modulation allows three-dimensional imaging of multiple volumes without encoding the space between volumes, thus reducing scan time. Parallel imaging further accelerates data acquisition by exploiting coil sensitivity differences between volumes. This work compared bilateral breast image quality from self-calibrated parallel imaging reconstruction methods such as modified sensitivity encoding, generalized autocalibrating partially parallel acquisitions and autocalibrated reconstruction for Cartesian sampling (ARC) for data with and without slab-phase modulation. A study showed an improvement of image quality by incorporating slab-phase modulation. Geometry factors measured from phantom images were more homogenous and lower on average when slab-phase modulation was used for both mSENSE and GRAPPA reconstructions. The resulting improved signal-to-noise ratio (SNR) was validated for in vivo images as well using ARC instead of GRAPPA, illustrating average SNR efficiency increases in mSENSE by 5% and ARC by 8% based on region of interest analysis. Furthermore, aliasing artifacts from mSENSE reconstruction were reduced when slab-phase modulation was used. Overall, slab-phase modulation with parallel imaging improved image quality and efficiency for 3D bilateral breast imaging.

    View details for DOI 10.1002/mrm.22115

    View details for Web of Science ID 000271431200016

    View details for PubMedID 19780156

  • 3.0-T MR-Guided Focused Ultrasound for Preoperative Localization of Nonpalpable Breast Lesions: An Initial Experimental Ex Vivo Study JOURNAL OF MAGNETIC RESONANCE IMAGING Schmitz, A. C., Van den Bosch, M. A., Rieke, V., Dirbas, F. M., Pauly, K. B., Mali, W. P., Daniel, B. L. 2009; 30 (4): 884-889

    Abstract

    To compare the accuracy of magnetic resonance-guided focused ultrasound (MRgFUS) with MR-guided needle-wire placement (MRgNW) for the preoperative localization of nonpalpable breast lesions.In this experimental ex vivo study, 15 turkey breasts were used. In each breast phantom an artificial nonpalpable "tumor" was created by injecting an aqueous gel containing gadolinium. MRgFUS (n = 7) was performed with the ExAblate 2000 system (InSightec). With MRgFUS the ablated tissue changes in color and increases in stiffness. A rim of palpable and visible ablations was created around the tumor to localize the tumor and facilitate excision. MRgNW (n = 8) was performed by MR-guided placement of an MR-compatible needle-wire centrally in the tumor. After surgical excision of the tumor, MR images were used to evaluate tumor-free margins (negative/positive), minimum tumor-free margin (mm), and excised tissue volume (cm(3)).With MRgFUS localization no positive margins were found after excision (0%). With MRgNW two excision specimens (25%) had positive margins (P = 0.48). Mean minimum tumor-free margin (+/-SD) with MRgFUS was significantly larger (5.5 +/- 2.4 mm) than with MRgNW (0.9 +/- 1.4 mm) (P < 0.001). Mean volume +/- SD of excised tissue did not differ between MRgFUS and MRgNW localization, ie, 44.0 +/- 9.4 cm(3) and 39.5 +/- 10.7 cm(3) (P = 0.3).The results of this experimental ex vivo study indicate that MRgFUS can potentially be used to localize nonpalpable breast lesions in vivo.

    View details for DOI 10.1002/jmri.21896

    View details for PubMedID 19787736

  • MRI GUIDANCE FOR ACCELERATED PARTIAL BREAST IRRADIATION IN PRONE POSITION: IMAGING PROTOCOL DESIGN AND EVALUATION 50th Annual Meeting of the American-Society-for-Therapeutic-Radiology-and-Oncology (ASTRO) Ahn, K., Hargreaves, B. A., Alley, M. T., Horst, K. C., Luxton, G., Daniel, B. L., Hristov, D. ELSEVIER SCIENCE INC. 2009: 285–93

    Abstract

    To design and evaluate a magnetic resonance imaging (MRI) protocol to be incorporated in the simulation process for external beam accelerated partial breast irradiation.An imaging protocol was developed based on an existing breast MRI technique with the patient in the prone position on a dedicated coil. Pulse sequences were customized to exploit T1 and T2 contrast mechanisms characteristic of lumpectomy cavities. A three-dimensional image warping algorithm was included to correct for geometric distortions related to nonlinearity of spatially encoding gradients. Respiratory motion, image distortions, and susceptibility artifacts of 3.5-mm titanium surgical clips were examined. Magnetic resonance images of volunteers were acquired repeatedly to analyze residual setup deviations resulting from breast tissue deformation.The customized sequences generated high-resolution magnetic resonance images emphasizing lumpectomy cavity morphology. Respiratory motion was negligible with the subject in the prone position. The gradient-induced nonlinearity was reduced to less than 1 mm in a region 15 cm away from the isocenter of the magnet. Signal-void regions of surgical clips were 4 mm and 8 mm for spin echo and gradient echo images, respectively. Typical residual repositioning errors resulting from breast deformation were estimated to be 3 mm or less.MRI guidance for accelerated partial breast irradiation with the patient in the prone position with adequate contrast, spatial fidelity, and resolution is possible.

    View details for DOI 10.1016/j.ijrobp.2009.03.063

    View details for Web of Science ID 000269328700045

    View details for PubMedID 19632067

  • MRI-Guided Cryoablation: In Vivo Assessment of Focal Canine Prostate Cryolesions JOURNAL OF MAGNETIC RESONANCE IMAGING Josan, S., Bouley, D. M., van den Bosch, M., Daniel, B. L., Pauly, K. B. 2009; 30 (1): 169-176

    Abstract

    To analyze the appearance of acute and chronic canine prostate cryolesions on T1-weighted (T1w) and T2-weighted (T2w) magnetic resonance imaging (MRI) and compare them with contrast-enhanced (CE) MRI and histology for a variety of freezing protocols.Three different freezing protocols were used in canine prostate cryoablation experiments. Six acute and seven chronic (survival times ranging between 4-53 days) experiments were performed. The change in T2w signal intensity was correlated with freezing protocol parameters. The lesion area on T2w MRI was compared to CE-MRI. Histopathologic evaluation of the cryolesions was performed and visually compared to the appearance on MRI.The T2w signal increased from pre- to postfreeze at the site of the cryolesion, and the enhancement was higher for smaller freeze area and duration. The T2w lesion area was between the CE nonperfused area and the hyperenhancing CE rim. The appearance of the lesion on T1w and T2w imaging over time correlated with outcome on pathology.T1w and T2w MRI can potentially be used to assess cryolesions and to monitor tissue response over time following cryoablation.

    View details for DOI 10.1002/jmri.21827

    View details for PubMedID 19557805

  • MR Voiding Cystography for Evaluation of Vesicoureteral Reflux AMERICAN JOURNAL OF ROENTGENOLOGY Vasanawala, S. S., Kennedy, W. A., Ganguly, A., Fahrig, R., Rieke, V., Daniel, B., Barth, R. A. 2009; 192 (5): W206-W211

    Abstract

    The purpose of our study is to present a real-time interactive continuous fluoroscopy MRI technique for vesicoureteral reflux (VUR) diagnosis.MR voiding cystography with a real-time interactive MR fluoroscopic technique on an open MRI magnet is feasible for the evaluation of VUR in children.

    View details for DOI 10.2214/AJR.08.1251

    View details for Web of Science ID 000265387300045

    View details for PubMedID 19380524

  • Improved Half RF Slice Selectivity in the Presence of Eddy Currents with Out-of-Slice Saturation MAGNETIC RESONANCE IN MEDICINE Josan, S., Kaye, E., Pauly, J. M., Daniel, B. L., Pauly, K. B. 2009; 61 (5): 1090-1095

    Abstract

    Ultrashort echo time imaging with half RF pulse excitation is sensitive to eddy currents induced by the slice-select gradient that distorts the half pulse slice profile. This work demonstrates improvements in the half pulse profile by using spatial saturation on both sides of the imaged slice to suppress the out-of-slice magnetization. This effectively improves the selectivity of the half pulse excitation profile. A quadratic phase RF pulse with high bandwidth and selectivity was used to achieve a wide saturation band with sharp edges. Experimental results demonstrate substantially improved slice selectivity and R(2)* quantitation accuracy obtained with the out-of-slice saturation. This approach is effective in making short T(2) imaging and quantitation with half pulses less sensitive to eddy currents.

    View details for DOI 10.1002/mrm.21914

    View details for PubMedID 19319972

  • Double Half RF Pulses for Reduced Sensitivity to Eddy Currents in UTE Imaging MAGNETIC RESONANCE IN MEDICINE Josan, S., Pauly, J. M., Daniel, B. L., Pauly, K. B. 2009; 61 (5): 1083-1089

    Abstract

    Ultrashort echo time imaging with half RF pulse excitation is challenging as eddy currents induced by the slice-select gradient distort the half pulse slice profile. This work presents two pulses with T(2)-dependent slice profiles that are less sensitive to eddy currents. The double half pulse improves the slice selectivity for long T(2) components, while the inverted double half pulse suppresses the unwanted long T(2) signal. Thus, both approaches prevent imperfect cancellation of out-of-slice signal from contaminating the desired slice. Experimental results demonstrate substantially improved slice selectivity and R(2)* quantitation accuracy with these pulses. These pulses are effective in making short T(2) imaging and quantitation less sensitive to eddy currents and provide an alternative to time-consuming gradient characterization.

    View details for DOI 10.1002/mrm.21879

    View details for PubMedID 19235919

  • MR Imaging-guided Percutaneous Cryoablation of the Prostate in an Animal Model: In Vivo Imaging of Cryoablation-induced Tissue Necrosis with Immediate Histopathologic Correlation 32nd Annual Meeting of the Society-of-Interventional-Radiology (SIR) van den Bosch, M. A., Josan, S., Bouley, D. M., Chen, J., Gill, H., Rieke, V., Butts-Pauly, K., Daniel, B. L. ELSEVIER SCIENCE INC. 2009: 252–58

    Abstract

    To evaluate the feasibility of magnetic resonance (MR) imaging-guided percutaneous cryoablation of normal canine prostates and to identify MR imaging features that accurately predict the area of tissue damage at a microscopic level.Six adult male mixed-breed dogs were anesthetized, intubated, and placed in a 0.5-T open MR imaging system. A receive-only endorectal coil was placed, and prostate location and depth were determined on T1-weighted fast spin-echo (FSE) MR imaging. After placement of cryoprobes and temperature sensors, three freezing protocols were used to ablate prostate tissue. Ice ball formation was monitored with T1-weighted FSE imaging. Tissue necrosis area was assessed with contrast-enhanced weighted MR imaging and compared with histopathologic findings.A total of 12 cryolesions (mean size, 1.2 cm) were bilaterally created in six prostates. Ice ball formation was oval and signal-free on T1-weighted FSE sequences in all cases. Postprocedural contrast-enhanced MR imaging typically showed a nonenhancing area of low signal intensity centrally located within the frozen area, surrounded by a bright enhancing rim in all cases. On histopathologic examination, two distinct zones were identified within cryolesions. Centrally, a necrotic zone with complete cellular destruction and hemorrhage was found. Between this necrotic zone and normal glandular tissue, a zone of fragmented and intact glands, interstitial edema, and rare acute inflammatory cells was seen. Correlation between nonenhancement on contrast-enhanced weighted MR images and tissue necrosis on pathologic examination was consistent within all six dogs.MR imaging-guided cryoablation of the prostate is technically feasible. The nonenhancing area on postablation contrast-enhanced weighted MR imaging accurately predicts the area of cryoablation-induced tissue necrosis on pathologic analysis.

    View details for DOI 10.1016/j.jvir.2008.10.030

    View details for PubMedID 19091600

  • Accelerated Bilateral Dynamic Contrast-Enhanced 3D Spiral Breast MRI Using TSENSE JOURNAL OF MAGNETIC RESONANCE IMAGING Han, M., Daniel, B. L., Hargreaves, B. A. 2008; 28 (6): 1425-1434

    Abstract

    To assess the ability of adaptive sensitivity encoding incorporating temporal filtering (TSENSE) to accelerate bilateral dynamic contrast-enhanced (DCE) 3D breast MRI.Bilateral DCE breast magnetic resonance imaging (MRI) exams were performed using a dual-band water-only excitation and a "stack-of-spirals" imaging trajectory. TSENSE was applied in the slab direction with an acceleration factor of 2. Four different techniques for sensitivity map calculation were compared by analyzing resultant contrast uptake curves qualitatively and quantitatively for 10 patient datasets. In addition, image quality and temporal resolution were compared between unaccelerated and TSENSE images.TSENSE can increase temporal resolution by a factor of 2 in DCE imaging, providing better depiction of contrast uptake curves and good image quality. Of the different methods tested, calculation of static sensitivity maps by averaging late postcontrast frames yields the lowest aliasing artifact level based on ROI analysis.TSENSE acceleration combined with 3D spiral imaging is very time-efficient, providing 11-second temporal resolution and 1.1 x 1.1 x 3 mm(3) spatial resolution over a 20 x 20 x 10 cm(3) field of view for each breast.

    View details for DOI 10.1002/jmri.21427

    View details for Web of Science ID 000261270500014

    View details for PubMedID 19025951

  • Improved slice selection for R2*mapping during cryoablation with eddy current compensation JOURNAL OF MAGNETIC RESONANCE IMAGING Lu, A., Daniel, B. L., Pauly, J. M., Pauly, K. B. 2008; 28 (1): 190-198

    Abstract

    To improve the slice profile and image quality of R2* mapping in the iceball during cryoablation with ultrashort echo time (UTE) imaging by compensating for eddy currents induced by the selective gradient when half-pulse radiofrequency (RF) excitation is employed to achieve UTEs.A method to measure both B0 and linear eddy currents simultaneously is first presented. This is done with a least-square fitting process on calibration data collected on a phantom. Eddy currents during excitation are compensated by redesigning the RF pulse and the selective gradient accordingly, while that resultant from the readout gradient are compensated for during image reconstruction. In vivo data were obtained continuously during the cryoablation experiments to calculate the R2* values in the iceball and to correlate them with the freezing process.Image quality degradation due to eddy currents is significantly reduced with the proposed approaches. R2* maps of iceball throughout the cryoablation experiments were achieved with improved quality.The proposed approaches are effective for compensating eddy currents during half-pulse RF excitation as well as readout. TEs as short as 100 microsec were obtained, allowing R2* maps to be obtained from frozen tissues with improved quality.

    View details for DOI 10.1002/jmri.21396

    View details for PubMedID 18581340

  • Image-guided focused ultrasound ablation of breast cancer: current status, challenges, and future directions EUROPEAN RADIOLOGY Schmitz, A. C., Gianfelice, D., Daniel, B. L., Mali, W. P., van den Bosch, M. A. 2008; 18 (7): 1431-1441

    Abstract

    Image-guided focussed ultrasound (FUS) ablation is a non-invasive procedure that has been used for treatment of benign or malignant breast tumours. Image-guidance during ablation is achieved either by using real-time ultrasound (US) or magnetic resonance imaging (MRI). The past decade phase I studies have proven MRI-guided and US-guided FUS ablation of breast cancer to be technically feasible and safe. We provide an overview of studies assessing the efficacy of FUS for breast tumour ablation as measured by percentages of complete tumour necrosis. Successful ablation ranged from 20% to 100%, depending on FUS system type, imaging technique, ablation protocol, and patient selection. Specific issues related to FUS ablation of breast cancer, such as increased treatment time for larger tumours, size of ablation margins, methods used for margin assessment and residual tumour detection after FUS ablation, and impact of FUS ablation on sentinel node procedure are presented. Finally, potential future applications of FUS for breast cancer treatment such as FUS-induced anti-tumour immune response, FUS-mediated gene transfer, and enhanced drug delivery are discussed. Currently, breast-conserving surgery remains the gold standard for breast cancer treatment.

    View details for DOI 10.1007/s00330-008-0906-0

    View details for Web of Science ID 000256823300015

    View details for PubMedID 18351348

    View details for PubMedCentralID PMC2441491

  • Monitoring prostate thermal therapy with diffusion-weighted MRI MAGNETIC RESONANCE IN MEDICINE Chen, J., Daniel, B. L., Diederich, C. J., Bouley, D. M., Van den Bosch, M. A., Kinsey, A. M., Sommer, G., Pauly, K. B. 2008; 59 (6): 1365-1372

    Abstract

    For MR-guided minimally invasive therapies, it is important to have a repeatable and reliable tissue viability evaluation method. The use of diffusion-weighted MRI (DWI) to evaluate tissue damage was assessed in 19 canine prostates with cryoablation or high-intensity ultrasound (HIU) ablation. The apparent diffusion coefficient (ADC) trace value was measured in the treated tissue immediately upon the procedure and on the posttreatment follow-up. For the acute lesions, the ADC value decreased to (1.05+/-0.25)x10(-3) mm2/s, as compared to (1.64+/-0.24)x10(-3) mm2/s before the treatment. There was no statistical difference between previously frozen or previously ultrasound-heated lesions in terms of the 36% ADC reduction (P=0.66). The ADC decrease occurred early during the course of the treatment, which appears to complicate DWI-based thermometry. Over time, the ADC value increased as the tissue recovered and regenerated. This study shows that DWI could be a promising method to monitor prostate thermal therapies and to provide insight on tissue damage and tissue remodeling after injury.

    View details for DOI 10.1002/mrm.21589

    View details for PubMedID 18506801

  • Reduction of truncation artifacts in rapid 3D articular cartilage imaging JOURNAL OF MAGNETIC RESONANCE IMAGING Rakow-Penner, R., Gold, G., Daniel, B., Stevens, K., Rosenberg, J., Mazin, S. 2008; 27 (4): 860-865

    Abstract

    To reduce Gibbs ringing artifact in three-dimensional (3D) articular knee cartilage imaging with linear prediction (LP).A reconstruction method using LP in 3D was applied to truncated data sets of six healthy knees. The technique first linearizes the data before applying the prediction algorithm. Three radiologists blindly reviewed and ranked images of the full, truncated, and predicted data sets. Statistical analysis of the radiologists' reviews was performed for image quality, clinical acceptability of the images, and equivalence with the gold standard.LP applied to 3D knee cartilage imaging allows for 40% decreased scan time while providing image quality with statistical equivalence to a full data set.3D spoiled gradient echo imaging (SPGR) knee cartilage imaging requires significant scan time. This 40% reduction in scan time will allow such scans to be more feasible without sacrificing clinical acceptability.

    View details for DOI 10.1002/jmri.21312

    View details for PubMedID 18383247

  • Magnetic resonance galactography: A feasibility study in women with prior atypical breast duct cytology BREAST JOURNAL Kurian, A. W., Hartman, A., Mills, M. A., Logan, L. J., Sawyer, A. M., Ford, J. M., Daniel, B. L. 2008; 14 (2): 211-214

    View details for Web of Science ID 000253712200022

    View details for PubMedID 18248552

  • Design, performance, and applications of a hybrid X-Ray/MR system for interventional guidance PROCEEDINGS OF THE IEEE Fahrig, R., Ganguly, A., Lillaney, P., Bracken, J., Rowlands, J. A., Wen, Z., Yu, H., Rieke, V., Santos, J. M., Pauly, K. B., Sze, D. Y., Frisoli, J. K., Daniel, B. L., Pelc, N. J. 2008; 96 (3): 468-480
  • A hybrid radiography/MRI system for combining hysterosalpingography and MRI in infertility patients: Initial experience AMERICAN JOURNAL OF ROENTGENOLOGY Freeman-Walsh, C. B., Fahrig, R., Ganguly, A., Rieke, V., Daniel, B. L. 2008; 190 (2): W157-W160

    Abstract

    We evaluated the feasibility of a prototype hybrid radiography/MRI system in evaluating infertility patients. Pelvic MRI was followed by hysterosalpingography (HSG) without moving the patient. This system allowed evaluation of tubal patency and cross-sectional imaging with one examination.Our hybrid radiography/MRI system provided good-quality HSG and MR images. We were able to assess tubal anatomy and patency and uterine anatomy and to detect pelvic abnormalities, including fibroids and adenomyosis. Furthermore, MR images and radiographs were superimposed to clarify HSG findings.

    View details for DOI 10.2214/AJR.07.2282

    View details for Web of Science ID 000252932100049

    View details for PubMedID 18212200

  • MRI-guided radiofrequency ablation of breast cancer: Preliminary clinical experience JOURNAL OF MAGNETIC RESONANCE IMAGING van den Bosch, M., Daniel, B., Rieke, V., Butts-Pauly, K., Kermit, E., Jeffrey, S. 2008; 27 (1): 204-208

    Abstract

    This study was designed to demonstrate the feasibility of MRI-guided radiofrequency ablation (RFA) of breast cancer. A total of three women diagnosed with invasive ductal breast cancer were treated with percutaneous MRI-guided RFA, according to a treat and resect protocol, in our hospital. RFA procedures were performed in an open 0.5T Signa-SP imager allowing direct patient access and real-time monitoring of the procedure. In all patients ablation was performed with a 15-gauge insulated MRI-compatible multiple needle probe. MRI thermometry and contrast-enhanced postablation MRI were used to evaluate the ablation process. Patients underwent lumpectomy within a week of the RFA procedure. Histopathology confirmed successful (100%) tumor ablation in one patient, and partial tumor destruction (33% and 50%, respectively) in two patients. Challenges of MRI-guided breast RFA that need to be solved to facilitate progress of the technique toward clinical practice are discussed.

    View details for DOI 10.1002/jmri.21190

    View details for PubMedID 18050333

  • Design of magnetic resonance imaging protocol for accelerated partial breast irradiation in prone position and estimation of treatment margin 50th Annual Meeting of the American-Society-for-Therapeutic-Radiology-and-Oncology (ASTRO) Ahn, K., Hargreaves, B. A., Alley, M. T., Horst, K. C., Daniel, B. L., Hristov, D. ELSEVIER SCIENCE INC. 2008: S510–S510
  • Does size matter? Likelihood of cancer in MRI-detected lesions less than 5 mm AMERICAN JOURNAL OF ROENTGENOLOGY Van den Bosch, M. A., Ikeda, D. M., Daniel, B. L. 2007; 188 (6): W571-W571

    View details for DOI 10.2214/AJR.06.1206

    View details for Web of Science ID 000246665800058

    View details for PubMedID 17515352

  • Breast image registration using SIFT and TPS hybrid method 49th Annual Meeting of the American-Association-of-Physicists-in-Medicine Xie, Y., Faranesh, T., Daniel, B., Xing, L. AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS. 2007: 2352–53
  • Ductal pattern enhancement on magnetic resonance imaging of the breast due to ductal lavage BREAST JOURNAL Ghanouni, P., Kurian, A. W., Margolis, D., Hartman, A., Mills, M. A., Plevritis, S. K., Ford, J. M., Daniel, B. L. 2007; 13 (3): 281-286

    Abstract

    Our purpose is to describe the appearance of breast ductal enhancement found on magnetic resonance imaging (MRI) after breast ductal lavage (DL). We describe a novel etiology of enhancement in a ductal pattern on postcontrast MRI of the breast. Knowledge of the potential for breast MRI enhancement subsequent to DL, which can mimic the appearance of a pathologic lesion, is critical to the care of patients who undergo breast MRI and DL or other intraductal cannulation procedures.

    View details for PubMedID 17461903

  • Independent phase modulation for efficient dual-band 3D imaging MAGNETIC RESONANCE IN MEDICINE Hargreaves, B. A., Cunningham, C. H., Pauly, J. M., Daniel, B. L. 2007; 57 (4): 798-802

    Abstract

    Certain applications of MRI, such as bilateral breast imaging, require simultaneous imaging of multiple volumes. Although image data can be acquired sequentially, the SNR is often improved if both slabs are excited and imaged together, typically with phase encoding across a volume including both slabs and the space between them. The use of independent phase modulation of multiple slabs eliminates the need to encode empty space between slabs, which can result in a significant time reduction. Each slab is excited with a phase proportional to phase-encode number such that the slab positions in the acquired data are shifted to reduce empty space. With careful consideration this technique is compatible with different pulse sequences (e.g., spin-echo, gradient-echo, RF spoiling, and balanced SSFP (bSSFP)) and acceleration strategies (e.g., partial k-space and parallel imaging). This technique was demonstrated in phantoms and applied to bilateral breast imaging, where scan times were reduced by 20-30%.

    View details for DOI 10.1002/mrm.21180

    View details for Web of Science ID 000245474600019

    View details for PubMedID 17390355

  • Correlation of contrast-enhanced MR images with the histopathology of minimally invasive thermal and cryoablation cancer treatments in normal dog prostates. Proceedings of SPIE--the International Society for Optical Engineering Bouley, D. M., Daniel, B., Pauly, K. B., Liu, E., Kinsey, A., NAU, W., Diederich, C. J., Sommer, G. 2007; 6440: 644006-?

    Abstract

    Magnetic Resonance Imaging (MRI) is a promising tool for visualizing the delivery of minimally invasive cancer treatments such as high intensity ultrasound (HUS) and cryoablation. We use an acute dog prostate model to correlate lesion histopathology with contrast-enhanced (CE) T1 weighted MR images, to aid the radiologists in real time interpretation of in vivo lesion boundaries and pre-existing lesions. Following thermal or cryo treatments, prostate glands are removed, sliced, stained with the vital dye triphenyl tetrazolium chloride, photographed, fixed and processed in oversized blocks for routine microscopy. Slides are scanned by Trestle Corporation at .32 microns/pixel resolution, the various lesions traced using annotation software, and digital images compared to CE MR images. Histologically, HUS results in discrete lesions characterized by a "heat-fixed" zone, in which glands subjected to the highest temperatures are minimally altered, surrounded by a rim or "transition zone" composed of severely fragmented, necrotic glands, interstitial edema and vascular congestion. The "heat-fixed" zone is non-enhancing on CE MRI while the "transition zone" appears as a bright, enhancing rim. Likewise, the CE MR images for cryo lesions appear similar to thermally induced lesions, yet the histopathology is significantly different. Glands subjected to prolonged freezing appear totally disrupted, coagulated and hemorrhagic, while less intensely frozen glands along the lesion edge are partially fragmented and contain apoptotic cells. In conclusion, thermal and cryo-induced lesions, as well as certain pre-existing lesions (cystic hyperplasia - non-enhancing, chronic prostatitis - enhancing) have particular MRI profiles, useful for treatment and diagnostic purposes.

    View details for PubMedID 25076818

  • Correlation of contrast-enhanced NM images with the histopathology of minimally invasive thermal and cryoablation cancer treatments in normal dog prostates Conference on Thermal Treatment of Tissue - Energy Delivery and Assessment IV Bouley, D. M., Daniel, B., Butts Pauly, K., Liu, E., Kinse, A., NAU, W., Diederich, C. J., Sommer, G. SPIE-INT SOC OPTICAL ENGINEERING. 2007

    Abstract

    Magnetic Resonance Imaging (MRI) is a promising tool for visualizing the delivery of minimally invasive cancer treatments such as high intensity ultrasound (HUS) and cryoablation. We use an acute dog prostate model to correlate lesion histopathology with contrast-enhanced (CE) T1 weighted MR images, to aid the radiologists in real time interpretation of in vivo lesion boundaries and pre-existing lesions. Following thermal or cryo treatments, prostate glands are removed, sliced, stained with the vital dye triphenyl tetrazolium chloride, photographed, fixed and processed in oversized blocks for routine microscopy. Slides are scanned by Trestle Corporation at .32 microns/pixel resolution, the various lesions traced using annotation software, and digital images compared to CE MR images. Histologically, HUS results in discrete lesions characterized by a "heat-fixed" zone, in which glands subjected to the highest temperatures are minimally altered, surrounded by a rim or "transition zone" composed of severely fragmented, necrotic glands, interstitial edema and vascular congestion. The "heat-fixed" zone is non-enhancing on CE MRI while the "transition zone" appears as a bright, enhancing rim. Likewise, the CE MR images for cryo lesions appear similar to thermally induced lesions, yet the histopathology is significantly different. Glands subjected to prolonged freezing appear totally disrupted, coagulated and hemorrhagic, while less intensely frozen glands along the lesion edge are partially fragmented and contain apoptotic cells. In conclusion, thermal and cryo-induced lesions, as well as certain pre-existing lesions (cystic hyperplasia - non-enhancing, chronic prostatitis - enhancing) have particular MRI profiles, useful for treatment and diagnostic purposes.

    View details for DOI 10.1117/12.701049

    View details for Web of Science ID 000246494100005

    View details for PubMedCentralID PMC4112763

  • Evaluation of thermal and cryo lesions by diffusion-weighted MRI Conference on Thermal Treatment of Tissue - Energy Delivery and Assessment IV Chen, J., Daniel, B., Bouley, D., Sommer, G., Butts Pauly, K. SPIE-INT SOC OPTICAL ENGINEERING. 2007

    View details for DOI 10.1117/12.703255

    View details for Web of Science ID 000246494100006

  • Resolution of hypoalbuminemia after excision of malignant phyllodes tumor CLINICAL BREAST CANCER Samiian, L., Daniel, B., Wapnir, I. 2006; 7 (5): 411-412

    Abstract

    A 42-year-old woman presented with a rapidly growing tumor of the breast accompanied by anemia (7.4 g/dL), hypoalbuminemia (1.6 g/dL), and increased alkaline phosphatase (256 U/L). Magnetic resonance imaging of the breast demonstrated a heterogeneous mass composed of verrucous solid components with hemorrhagic areas. There was no evidence of cachexia, and the metastatic workup was negative. Final pathology revealed a 22-cm malignant phyllodes tumor. Hypoalbuminemia and alkaline phosphatase quickly resolved after surgical excision without any further treatment.

    View details for PubMedID 17239267

  • Water-selective spectral-spatial contrast-enhanced breast MRI for cancer detection in patients with extracapsular and injected free silicone MAGNETIC RESONANCE IMAGING Po, J., Margolis, D. J., Cunningham, C. H., Herfkens, R. J., Ikeda, D. M., Daniel, B. L. 2006; 24 (10): 1363-1367

    Abstract

    This study investigates the use of contrast-enhanced, T1-weighted, water-selective spectral-spatial 3D gradient echo magnetic resonance imaging (MRI) with magnetization transfer (3DSSMT) for detecting breast cancer in patients with intraparenchymal silicone.Water-selective 3DSSMT provides superior fat and silicone suppression in patients with free silicone as compared with conventional fat saturation. It enables direct, high-quality, high-spatial-resolution, T1-weighted breast MRI of contrast enhancement without the need for subtraction processing and aids diagnosis of cancer in the breast with free silicone.

    View details for DOI 10.1016/j.mri.2006.08.003

    View details for Web of Science ID 000242946800011

    View details for PubMedID 17145408

  • MRI-guided needle localization of suspicious breast lesions: results of a freehand technique EUROPEAN RADIOLOGY van den Bosch, M. A., Daniel, B. L., Pal, S., Nowels, K. W., Birdwell, R. L., Jeffrey, S. S., Ikeda, D. M. 2006; 16 (8): 1811-1817

    Abstract

    Magnetic resonance imaging (MRI) can detect clinically and mammographically occult breast lesions. In this study we report the results of MRI-guided needle localization of suspicious breast lesions by using a freehand technique. Preoperative MRI-guided single-needle localization was performed in 220 patients with 304 MRI-only breast lesions at our hospital between January 1997 and July 2004. Procedures were performed in an open 0.5-T Signa-SP imager allowing real-time monitoring, with patient in prone position, by using a dedicated breast coil. MRI-compatible hookwires were placed in a noncompressed breast by using a freehand technique. MRI findings were correlated with pathology and follow-up. MRI-guided needle localization was performed for a single lesion in 150 patients, for two lesions in 56 patients, and for three lesions in 14 patients. Histopathologic analysis of these 304 lesions showed 104 (34%) malignant lesions, 51 (17%) high-risk lesions, and 149 (49%) benign lesions. The overall lesion size ranged from 2.0-65.0 mm (mean 11.2 mm). No direct complications occurred. Follow-up MRI in 54 patients showed that two (3.7%) lesions were missed by surgical biopsy. MRI-guided freehand needle localization is accurate and allows localization of lesions anterior in the breast, the axillary region, and near the chest wall.

    View details for DOI 10.1007/s00330-006-0214-5

    View details for Web of Science ID 000238860700022

    View details for PubMedID 16683117

  • Cost-effectiveness of screening BRCA1/2 mutation carriers with breast magnetic resonance imaging JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Plevritis, S. K., Kurian, A. W., Sigal, B. M., Daniel, B. L., Ikeda, D. M., Stockdale, F. E., Garber, A. M. 2006; 295 (20): 2374-2384

    Abstract

    Women with inherited BRCA1/2 mutations are at high risk for breast cancer, which mammography often misses. Screening with contrast-enhanced breast magnetic resonance imaging (MRI) detects cancer earlier but increases costs and results in more false-positive scans.To evaluate the cost-effectiveness of screening BRCA1/2 mutation carriers with mammography plus breast MRI compared with mammography alone.A computer model that simulates the life histories of individual BRCA1/2 mutation carriers, incorporating the effects of mammographic and MRI screening was used. The accuracy of mammography and breast MRI was estimated from published data in high-risk women. Breast cancer survival in the absence of screening was based on the Surveillance, Epidemiology and End Results database of breast cancer patients diagnosed in the prescreening period (1975-1981), adjusted for the current use of adjuvant therapy. Utilization rates and costs of diagnostic and treatment interventions were based on a combination of published literature and Medicare payments for 2005.The survival benefit, incremental costs, and cost-effectiveness of MRI screening strategies, which varied by ages of starting and stopping MRI screening, were computed separately for BRCA1 and BRCA2 mutation carriers.Screening strategies that incorporate annual MRI as well as annual mammography have a cost per quality-adjusted life-year (QALY) gained ranging from less than 45,000 dollars to more than 700,000 dollars, depending on the ages selected for MRI screening and the specific BRCA mutation. Relative to screening with mammography alone, the cost per QALY gained by adding MRI from ages 35 to 54 years is 55,420 dollars for BRCA1 mutation carriers, 130,695 dollars for BRCA2 mutation carriers, and 98,454 dollars for BRCA2 mutation carriers who have mammographically dense breasts.Breast MRI screening is more cost-effective for BRCA1 than BRCA2 mutation carriers. The cost-effectiveness of adding MRI to mammography varies greatly by age.

    View details for PubMedID 16720823

  • In vivo porcine liver radiofrequency ablation with simultaneous MR temperature imaging 11th Annual Meeting of the International-Society-for-Magnetic-Resonance-in-Medicine Vigen, K. K., Jarrard, J., Rieke, V., Frisoli, J., Daniel, B. L., Pauly, K. B. JOHN WILEY & SONS INC. 2006: 578–84

    Abstract

    To demonstrate in vivo MR-guided temperature mapping during radiofrequency (RF) ablation of the liver with a commercially available RF generator modified to allow simultaneous RF treatment and MRI.A commercial RF generator was modified using passive filtering to allow the continuous application of the treatment current during MRI studies. A total of six ablations were performed with the device in vivo in three porcine livers, and imaging was concurrently performed using one of two different temperature mapping strategies.MR images acquired during RF ablation demonstrated no noticeable interference from the RF ablation device, which was operated at clinically relevant power levels. Temperature maps showed areas of heating that were consistent with the dimensions of the RF ablation probe, with some asymmetry (likely depending on the orientation of the probe and heat propagation effects), and some differences in heating-spot area stability depending on the specific temperature mapping strategy used. Lesions were visualized on post-ablation imaging and sectioning.The feasibility of performing RF ablation with a modified commercial RF generator simultaneously with MRI was demonstrated. Interference-free MR temperature maps were produced with both variable respiratory motion and mechanical ventilation, and showed the extent of heating as the ablation progressed.

    View details for DOI 10.1002/jmri.20528

    View details for Web of Science ID 000236577000022

    View details for PubMedID 16508928

  • Investigation of proton density for measuring tissue temperature JOURNAL OF MAGNETIC RESONANCE IMAGING Chen, J., Daniel, B. L., Pauly, K. B. 2006; 23 (3): 430-437

    Abstract

    To examine the temperature dependence of the proton density (PD) in both adipose and muscle tissues, and the application of the PD as a thermometry parameter in breast tissues.Porcine fat samples and bovine muscle samples were successively heated to temperatures ranging from 30 degrees C to 76 degrees C and then cooled. They were then imaged with a dual-echo spin-echo sequence. T1 and T2 effects were carefully corrected from the images. The apparent PD (APD) in regions of interest (ROIs) and the sum of the APD in all pixels (Sum_APD) were measured and analyzed by linear regression.APD in adipose tissue is linear and reversible, and changes with a 0.3%/ degrees C to 0.45%/ degrees C temperature variation. The temperature coefficient of Sum_APD in adipose tissue is approximately 0.29%/ degrees C, as predicted from the Boltzmann distribution. However, the results in muscle tissue are more variable. There is an offset in both APD and Sum_APD between heating and cooling phases, as well as different temperature coefficients between these two phases.The Sum_APD in adipose tissue validates the 1/T dependence on temperature. The APD is a potentially useful parameter for fat thermometry; however, its application in muscle tissue requires further investigation.

    View details for DOI 10.1002/jmri.20516

    View details for PubMedID 16463298

  • New Aspects on Pulse Sequence Design for Breast MRI. Eur Radiol Hargreaves BA, Cunningham CH, Han M, Pauly JM, Lee JH, Daniel BL 2006; 16 (Suppl 5): E35-E37
  • Relaxation times of breast tissue at 1.5T and 3T measured using IDEAL JOURNAL OF MAGNETIC RESONANCE IMAGING Rakow-Penner, R., Daniel, B., Yu, H. Z., Sawyer-Glover, A., Glover, G. H. 2006; 23 (1): 87-91

    Abstract

    To accurately measure T1 and T2 of breast fibroglandular tissue and fat at 1.5T and 3T, and note the partial volume effects of the admixture of fibroglandular tissue and fat on the relaxation rates using an approach termed iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL) imaging.T1 and T2 values were measured on the right breasts of five healthy women at 1.5T and 3T. T1 data were collected using two sequences: inversion recovery without IDEAL, and inversion recovery with IDEAL. T2 data were collected using Hahn Echo scans. SNR and CNR analyses were conducted on collected data.T1 increased for both fat (21%) and glandular tissue (17%) from 1.5T to 3T. Thus, the TR and TI of breast protocols at 3T should be lengthened accordingly. SNR more than doubled for both tissue types from 1.5T to 3T. IDEAL imaging demonstrated the partial volume effects of fat and glandular tissue on measuring relaxation rates of independent tissue types.With separated fat and water images, more precise measurements can be made for the lipid component in fat, and the water component in fibroglandular tissue.

    View details for DOI 10.1002/jmri.20469

    View details for Web of Science ID 000234488500013

    View details for PubMedID 16315211

  • Water-selective spectral-spatial contrast-enhanced breast MRI for cancer detection in patients with extracapsular and injected free silicone. Magn Reson Imaging Po J, Margolis DJA, Cunningham CH, Herfkens RJ, Ikeda DM, Daniel BL 2006; 24 (10): 1363-7
  • The lactating breast: Contrast-enhanced MR Imaging of normal tissue and cancer RADIOLOGY Espinosa, L. A., Daniel, B. L., Vidarsson, L., Zakhour, M., Ikeda, D. M., Herfkens, R. J. 2005; 237 (2): 429-436

    Abstract

    To retrospectively describe the magnetic resonance (MR) imaging characteristics of normal breast tissue and breast cancer in the setting of lactation.The HIPAA-compliant study was exempt from institutional approval, and informed consent was not required. Unilateral MR imaging of 10 breasts was performed in seven lactating patients aged 27-42 years. For the three patients in whom both breasts were imaged, each breast was imaged on a separate day. Nonenhanced T1-weighted and fat-saturated T2-weighted images and contrast material-enhanced dynamic three-dimensional (3D) T1-weighted spiral gradient-echo images interleaved with T1-weighted high-spatial-resolution 3D gradient-echo images (2.0 x 1.0 x 0.4-mm voxels) were obtained. Three readers in consensus assessed the glandular density, T2-weighted signal intensity, milk duct appearance, and contrast enhancement in normal and tumor-containing breast regions. The pharmacokinetic contrast enhancement parameters of tumors were compared with those of normal tissue by using Student t and Mann-Whitney tests.MR findings of normal breast tissue in the seven women included increased glandular density in six women, high T2-weighted signal intensity in six, dilated central ducts in seven, and rapid initial glandular contrast enhancement in seven. MR findings of invasive ductal carcinoma in five women, compared with findings of the normal glandular tissue, included lower T2-weighted signal intensity in five women, more avid and rapid contrast enhancement in five, and early contrast enhancement washout in four. One minute after contrast agent injection, tumor signal intensity increased significantly more than normal lactating tissue signal intensity (153% vs 60% from baseline, P = .016). The median two-compartment model K(21) exchange rate in the tumors, 0.078 sec(-1), was significantly faster than the K(21) exchange rate in normal tissue, 0.011 sec(-1) (P = .03).Normal lactating glands have increased density, high T2-weighted signal intensity, and rapid moderate contrast enhancement. Breast cancers are visible during lactation owing to their lower signal intensity and more intense initial contrast enhancement with early washout compared with normal breast tissue.

    View details for DOI 10.1148/radiol.2372040837

    View details for Web of Science ID 000232743300008

    View details for PubMedID 16244250

  • Pathologic correlates of false positive breast magnetic resonance imaging findings: which lesions warrant biopsy? 6th Annual Meeting of the American-Society-of-Breast-Surgeons Langer, S. A., Horst, K. C., Ikeda, D. M., Daniel, B. L., Kong, C. S., Dirbas, F. M. EXCERPTA MEDICA INC-ELSEVIER SCIENCE INC. 2005: 633–40

    Abstract

    Contrast-enhanced breast magnetic resonance imaging (MRI) is highly sensitive for breast cancer. However, adoption of breast MRI is hampered by frequent false positive (FP) findings. Though ultimately proven benign, these suspicious findings require biopsy due to abnormal morphology and/or kinetic enhancement curves that simulate malignancy on MRI. We hypothesized that analysis of a series of FP MRI findings could reveal a pattern of association between certain "suspicious" lesions and benign disease that might help avoid unnecessary biopsy of such lesions in the future.A retrospective chart review identified women undergoing breast MRI between June 1995 and March 2002 with FP findings identified by MRI alone. Lesions were retrospectively characterized according to an MRI Breast Imaging-Reporting and Data System lexicon and matched to pathology.Twenty-two women were identified with 29 FP lesions. Morphology revealed 1 focus (3.5%), 5 masses less than 5 mm (17%), 11 masses greater than 5 mm (38%), 1 (3.5%) linear enhancement, and 11 (38%) non-mass-like enhancement. Kinetic curves were suspicious in 15 (52%). Histology demonstrated 20 (69%) variants of normal tissue and 9 (31%) benign masses. MRI lesions less than 5 mm (n = 6, 20.5%) were small, well-delineated nodules of benign breast tissue.Suspicious MRI lesions less than 5 mm often represent benign breast tissue and could potentially undergo surveillance instead of biopsy.

    View details for DOI 10.1016/j.amjsurg.2005.06.030

    View details for PubMedID 16164938

  • Contrast-enhanced MRI of ductal carcinoma in situ: Characteristics of a new intensity-modulated parametric mapping technique correlated with histopathologic findings JOURNAL OF MAGNETIC RESONANCE IMAGING Mariano, M. N., van den Bosch, M. A., Daniel, B. L., Nowels, K. W., Birdwell, R. L., Fong, K. J., Desmond, P. S., Plevritis, S., Stables, L. A., Zakhour, M., Herfkens, R. J., Ikeda, D. M. 2005; 22 (4): 520-526

    Abstract

    To identify morphologic and dynamic enhancement magnetic resonance imaging (MRI) features of pure ductal carcinoma in situ (DCIS) by using a new intensity-modulated parametric mapping technique, and to correlate the MRI features with histopathologic findings.Fourteen patients with pure DCIS on pathology underwent conventional mammography and contrast-enhanced (CE) MRI using the intensity-modulated parametric mapping technique. The MR images were reviewed and the lesions were categorized according to morphologic and kinetic criteria from the ACR BI-RADS-MRI Lexicon, with BI-RADS 4 and 5 lesions classified as suspicious.With the use of a kinetic curve shape analysis, MRI classified seven of 14 lesions (50%) as suspicious, including four with initial-rapid/late-washout and three with initial-rapid/late-plateau. Using morphologic criteria, MRI classified 10/14 (71%) as suspicious, with the most prominent morphologic feature being a regional enhancement pattern. Using the intensity modulated parametric mapping technique, MRI classified 12/14 cases (86%) as suspicious. Parametric mapping identified all intermediate- and high-grade DCIS lesions.The intensity-modulated parametric mapping technique for breast MRI resulted in the highest detection rate for the DCIS cases. Furthermore, the parametric mapping technique identified all intermediate- and high-grade DCIS lesions, suggesting that a negative MRI using the parametric mapping technique may exclude intermediate- and high-grade DCIS. This finding has potential clinical implications.

    View details for DOI 10.1002/jmri.20405

    View details for PubMedID 16142701

  • Opinions of women with high inherited breast cancer risk about prophylactic mastectomy: an initial evaluation from a screening trial including magnetic resonance imaging and ductal lavage HEALTH EXPECTATIONS Kurian, A. W., Hartman, A. R., Mills, M. A., Ford, J. M., Daniel, B. L., Plevritis, S. K. 2005; 8 (3): 221-233

    Abstract

    Prophylactic mastectomy (PM) is often considered, but variably chosen by women at high inherited risk of breast cancer; few data exist on patient tolerance of intensive breast screening as an alternative to PM. We performed an evaluation of high-risk women's tolerance of a breast screening protocol using clinical breast examination, mammography, breast magnetic resonance imaging (MRI) and ductal lavage (DL), and of change in attitudes toward PM after screening.A questionnaire assessing tolerance of screening procedures and change in opinion towards PM was designed and administered to 43 study participants, after a median follow-up of 13 months. Responses were evaluated according to patient characteristics, including type of study-prompted interventions, BRCA mutation status, and prior history of cancer, via univariate analysis.Most patients [85.3% (68.9-95.1%)] were more opposed or unchanged in their attitudes towards PM after study participation, with only 14.7% (5.0-31.1%) less opposed (P = 0.017) despite a short-interval follow-up MRI rate of 71.7% and a biopsy rate of 37%. Lower rates of maximal discomfort were reported with mammogram [2.8% (0-14.5%)] and MRI [5.6% (0-18.7%)] than with DL [28.6% (14.6-46.3%)], with P = 0.035.Most high-risk women tolerated intensive breast screening well; they were not more inclined towards PM after participating. Future studies should prospectively evaluate larger numbers of high-risk women via multivariate analysis, to determine characteristics associated with preference for breast screening vs. PM.

    View details for PubMedID 16098152

  • Truly hybrid x-ray/MR imaging: Toward a streamlined clinical system 5th International Interventional MRI Symposium Ganguly, A., Wen, Z. F., Daniel, B. L., Butts, K., Kee, S. T., Rieke, V., Do, H. M., Pelc, N. J., Alley, M. T., Fahrig, R. ELSEVIER SCIENCE INC. 2005: 1167–77

    Abstract

    We have installed an improved X-ray/MR (XMR) truly hybrid system with higher imaging signal-to-noise ratio (SNR) and versatility than our first prototype. In our XMR design, a fixed anode X-ray fluoroscopy system is positioned between the two donut-shaped magnetic poles of a 0.5T GE Signa-SP magnet (SP-XMR). This paper describes the methods for increased compatibility between the upgraded x-ray and MR systems that have helped improve patient management.A GE OEC 9800 system (GE OEC Salt Lake City, UT) was specially reconfigured for permitting X-ray fluoroscopy inside the interventional magnet. A higher power X-ray tube, a new permanent tube mounting system, automatic exposure control (AEC), remote controlled collimators, choice of multiple frame rates, DICOM image compatibility, magnetically shimmed X-ray detector, X-ray compatible MR coil, and better RF shielding are the highlights of the new system. A total of 23 clinical procedures have been conducted with SP-XMR guidance of which five were performed using the new system.The 70% increased power for fluoroscopy, and a new 6 times higher power single frame imaging mode, has improved imaging capability. The choice of multiple imaging frame rates, AEC, and collimator control allow reduction in X-ray exposure to the patient. The DICOM formatting has permitted easy transfer of clinical images over the hospital PACS network. The increased MR compatibility of the detector and the X-ray transparent MR coil has enabled faster switching between X-ray and MR imaging modes.The improvements introduced in our SP-XMR system have further streamlined X-ray/MR hybrid imaging. Additional clinical procedures could benefit from the new SP-XMR imaging.

    View details for DOI 10.1016/j.acra.2005.03.076

    View details for PubMedID 16099685

  • In vivo MR thermometry of frozen tissue using R2* and signal intensity 5th International Interventional MRI Symposium Wansapura, J. P., Daniel, B. L., Vigen, K. K., Butts, K. ELSEVIER SCIENCE INC. 2005: 1080–84

    Abstract

    Cryoablation is one of several minimally invasive treatments that may be suitable for a targeted treatment of prostate cancer. Because efficacy is improved when a sufficiently cold end temperature is reached, the purpose of this work was to demonstrate an image-based thermometry method that could provide temperature maps throughout the frozen tissue. In five in vivo canine prostate cryoablation experiments performed under magnetic resonance imaging guidance, two MR parameters were measured and correlated to temperature: R2* and changes in signal intensity. R2* is elevated approximately linearly as tissue temperature decreases below the freezing point, while the signal intensity decreases exponentially. In vivo temperature maps with isotherms at -5 degrees C, -15 degrees C, and -30 degrees C are demonstrated.

    View details for DOI 10.1016/j.acra.2005.06.006

    View details for PubMedID 16112510

  • Magnetic resonance imaging characteristics of fibrocystic change of the breast INVESTIGATIVE RADIOLOGY van den Bosch, M. A., Daniel, B. L., Mariano, M. N., Nowels, K. N., Birdwell, R. L., Fong, K. J., Desmond, P. S., Plevritis, S., Stables, L. A., Zakhour, M., Herfkens, R. J., Ikeda, D. M. 2005; 40 (7): 436-441

    Abstract

    The objective of this study was to identify magnetic resonance imaging (MRI) characteristics of fibrocystic change (FCC) of the breast.Fourteen patients with a histopathologic diagnosis of solitary FCC of the breast underwent x-ray mammography and MRI of the breast. Three experienced breast imaging radiologists retrospectively reviewed the MRI findings and categorized the lesions on morphologic and kinetic criteria according to the ACR BI-RADS-MRI Lexicon.The most striking morphologic feature of fibrocystic change was nonmass-like regional enhancement found in 6 of 14 (43%) FCC lesions. Based on morphologic criteria alone, 12 of 14 (86%) lesions were correctly classified as benign. According to analysis of the time-intensity curves, 10 of 14 (71%) FCC lesions were correctly classified as benign.Although FCC has a wide spectrum of morphologic and kinetic features on MRI, it most often presents as a mass or a nonmass-like regional enhancing lesion with benign enhancement kinetics.

    View details for PubMedID 15973135

  • MRI features of mucosa-associated lymphoid tissue lymphoma in the breast AMERICAN JOURNAL OF ROENTGENOLOGY Espinosa, L. A., Daniel, B. L., Jeffrey, S. S., Nowels, K. W., Ikeda, D. M. 2005; 185 (1): 199-202

    View details for Web of Science ID 000229951900035

    View details for PubMedID 15972423

  • X-ray compatible radiofrequency coil for magnetic resonance imaging MAGNETIC RESONANCE IN MEDICINE Rieke, V., GANGULY, A., Daniel, B. L., Scott, G., Pauly, J. M., Fahrig, R., Pelc, N. J., Butts, K. 2005; 53 (6): 1409-1414

    Abstract

    The range of RF coils that can be used in combined X-ray/MR (XMR) systems is limited because many conventional coils contain highly X-ray attenuating materials that are visible in the X-ray images and potentially obscure patient anatomy. In this study, an X-ray compatible coil design that has minimal X-ray attenuation in the field of view (FOV) of the X-ray image is presented. In this design, aluminum is used for the loop conductor and discrete elements of the coil are eliminated from the X-ray FOV. A surface coil and an abdominal phased array coil were built using the X-ray compatible design. X-ray attenuation and MR imaging properties of the coils were evaluated and compared to conventional coils. The X-ray compatible phased array coil was used to image patients during two interventional procedures in the XMR system. The X-ray compatible coils allowed for fluoroscopic X-ray image acquisition, without degradation by the coil, while maintaining excellent MR imaging qualities.

    View details for DOI 10.1002/mrm.20494

    View details for PubMedID 15906285

  • In vivo prostate magnetic resonance spectroscopic imaging using two-dimensional J-resolved PRESS at 3 T MAGNETIC RESONANCE IN MEDICINE Kim, D. H., Margolis, D., Xing, L., Daniel, B., Spielman, D. 2005; 53 (5): 1177-1182

    Abstract

    In vivo magnetic resonance spectroscopic imaging of the prostate using single-voxel and multivoxel two-dimensional (2D) J-resolved sequences is investigated at a main magnetic field strength of 3 T. Citrate, an important metabolite often used to aid the detection of prostate cancer in magnetic resonance spectroscopic exams, can be reliably detected along with the other metabolites using this method. We show simulations and measurements of the citrate metabolite using 2D J-resolved spectroscopy to characterize the spectral pattern. Furthermore, using spiral readout gradients, the single-voxel 2D J-resolved method is extended to provide the spatial distribution information as well all within a reasonable scan time (17 min). Phantom and in vivo data are presented to illustrate the multivoxel 2D J-resolved spiral chemical shift imaging sequence.

    View details for DOI 10.1002/mrm.20452

    View details for Web of Science ID 000228796900026

    View details for PubMedID 15844143

  • An MRI-compatible semiautomated vacuum assisted breast biopsy system: Initial feasibility study JOURNAL OF MAGNETIC RESONANCE IMAGING Daniel, B. L., Freeman, L. J., Pyzoha, J. M., McCoy, T. D., Birdwell, R. L., Bouley, D. M., Movius, B., Hibner, J. A. 2005; 21 (5): 637-644

    Abstract

    To develop an MR-compatible vacuum-assisted core needle breast biopsy system.A vacuum-assisted breast biopsy system (Mammotome Hand Held; Ethicon Endo-Surgery, USA) was modified for freehand MRI-guided biopsy in an open, interventional 0.5-T scanner (Signa SP; GE, USA). Probes (11 gauge [G]) were fabricated without significant susceptibility artifact. These mate with an electromechanical hand piece and control system that were modified for use within the MRI scanner. A total of 62 breast lesions were simulated in the mammary tissues of six recently lactating sows by injecting between 0.1 and 1.0 mL of an aqueous gel containing dilute gadopentetate dimeglumine (Gd-DTPA) that formed a bright mass on T1-weighted imaging.Mechanical performance was satisfactory. Magnetic susceptibility and radiofrequency (RF) artifacts from the 11-G probe were negligible. T1-weighted fast spin echo (FSE) was used to guide biopsy. Up to eight samples were removed per lesion. Overall, 461 samples were obtained in 493 attempts (94%). Sample weights averaged 54 mg (N = 493) compared to 4.6 mg (N = 24) from 14-G titanium MRI-compatible needles. On average, 59% of the attempted samples yielded target lesion material.Preliminary results demonstrate the feasibility of a vacuum-assisted breast biopsy system in the MRI environment. Small 0.1-mL lesions can be biopsied without needle artifacts obscuring the target.

    View details for Web of Science ID 000228653600018

    View details for PubMedID 15834914

  • Rates of reexcision for breast cancer after magnetic resonance imaging-guided bracket wire localization JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS Wallace, A. M., Daniel, B. L., Jeffrey, S. S., Birdwell, R. L., Nowels, K. W., Dirbas, F. M., Schraedley-Desmond, P., Ikeda, D. M. 2005; 200 (4): 527-537

    Abstract

    We performed this study to determine rates of close or transected cancer margins after magnetic resonance imaging-guided bracket wire localization for nonpalpable breast lesions.Of 243 women undergoing MRI-guided wire localizations, 26 had MRI bracket wire localization to excise either a known cancer (n = 19) or a suspicious MRI-detected lesion (n = 7). We reviewed patient age, preoperative diagnosis, operative intent, mammographic breast density, MRI lesion size, MRI enhancement curve and morphology, MRI Breast Imaging Reporting and Data System (BI-RADS) assessment code, number of bracket wires, and pathology size. We analyzed these findings for their relationship to obtaining clear margins at first operative excision.Twenty-one of 26 (81%) patients had cancer. Of 21 patients with cancer, 12 (57%) had negative margins at first excision and 9 (43%) had close/transected margins. MRI size > or = 4 cm was associated with a higher reexcision rate (7 of 9, 78%) than those < 4 cm (2 of 12, 17%) (p = 0.009). MRI BI-RADS score, enhancement curve, morphology, and preoperative core biopsy demonstrating ductal carcinoma in situ (DCIS) were not predictive of reexcision. The average number of wires used for bracketing increased with lesion size, but was not associated with improved outcomes. On pathology, cancer size was smaller in patients with negative margins (12 patients, 1.2 cm) than in those with close/transected margins (9 patients, 4.6 cm) (p < 0.001). Reexcision was based on close/transected margins involving DCIS alone (6, 67%), infiltrating ductal carcinoma and DCIS (2, 22%), or infiltrating ductal carcinoma alone (1, 11%). Reexcision pathology demonstrated DCIS (3, 33%), no residual cancer (5, 55%), and 1 patient was lost to followup (1, 11%). Interestingly, cancer patients who required reexcision were younger (p = 0.022), but breast density was not associated with reexcision.To our knowledge, this is the first report of MRI-guided bracket wire localization. Patients with MRI-detected lesions less than 4 cm had clear margins at first excision; larger MRI-detected lesions were more likely to have close/transected margins. Reexcision was often because of DCIS and was the only pathology found at reexcision, perhaps because MRI is more sensitive for detecting invasive carcinoma than DCIS.

    View details for DOI 10.1016/j.jamcollsurg.2004.12.013

    View details for Web of Science ID 000228085200005

    View details for PubMedID 15804466

  • In vivo sonography through an open MRI breast coil to correlate sonographic and MRI findings AMERICAN JOURNAL OF ROENTGENOLOGY Lilienstein, J., Daniel, B. L., Ikeda, D. M. 2005; 184 (3): S49-S52

    View details for Web of Science ID 000227522800018

    View details for PubMedID 15728020

  • MRI-guided interstitial ultrasound thermal therapy of the prostate: A feasibility study in the canine model MEDICAL PHYSICS Nau, W. H., Diederich, C. J., Ross, A. B., Butts, K., Rieke, V., Bouley, D. M., Gill, H., Daniel, B., Sommer, G. 2005; 32 (3): 733-743

    Abstract

    The feasibility of MRI-guided interstitial ultrasound thermal therapy of the prostate was evaluated in an in vivo canine prostate model. MRI compatible, multielement interstitial ultrasound applicators were developed using 1.5 mm diameter cylindrical piezoceramic transducers (7 to 8 MHz) sectored to provide 180 degrees of angular directional heating. Two in vivo experiments were performed in canine prostate. The first using two interstitial ultrasound applicators, the second using three ultrasound applicators in conjunction with rectal and urethral cooling. In both experiments, the applicators were inserted transperineally into the prostate with the energy directed ventrally, away from the rectum. Electrical power levels of 5-17 W per element (approximately 1.6-5.4 W acoustic output power) were applied for heating periods of 18 and 48 min. Phase-sensitive gradient-echo MR imaging was used to monitor the thermal treatment in real-time on a 0.5 T interventional MRI system. Contrast-enhanced T1-weighted images and vital-stained serial tissue sections were obtained to assess thermal damage and correlate to real-time thermal contour plots and calculated thermal doses. Results from these studies indicated a large volume of ablated (nonstained) tissue within the prostate, extending 1.2 to 2.0 cm from the applicators to the periphery of the gland, with the dorsal margin of coagulation well-defined by the applicator placement and directionality. The shape of the lesions correlated well to the hypointense regions visible in the contrast-enhanced T1-weighted images, and were also in good agreement with the contours of the 52 degrees C threshold temperature and t43 > 240 min. This study demonstrates the feasibility of using directional interstitial ultrasound in conjunction with MRI thermal imaging to monitor and possibly control thermal coagulation within a targeted tissue volume while potentially protecting surrounding tissue, such as rectum, from thermal damage.

    View details for DOI 10.1118/1.1861163

    View details for Web of Science ID 000227910600010

    View details for PubMedID 15839345

  • MR-guided transjugular intrahepatic portosystemic shunt creation with use of a hybrid radiography/MR system 29th Annual Meeting of the Society-of-Interventional-Radiology (SIR) Kee, S. T., GANGULY, A., Daniel, B. L., Wen, Z. F., Butts, K., Shimikawa, A., Pelc, N. J., Fahrig, R., Dake, M. D. ELSEVIER SCIENCE INC. 2005: 227–34

    Abstract

    To evaluate the performance of a combined hybrid radiography/magnetic resonance (MR) unit to guide portal vein (PV) puncture during human transjugular intrahepatic portosystemic shunt (TIPS) creation.Fourteen patients undergoing TIPS creation were studied during standard clinical applications. Patients were anesthetized and then positioned in an open MR unit containing a flat-panel radiographic fluoroscopic unit. With use of a combination of fluoroscopy and MR imaging, the PV was accessed and the TIPS procedure was performed. A noncovered nitinol stent or a covered stent-graft was placed in the TIPS tract. Number of punctures required, total procedure time, fluoroscopy time, procedural success rate, complications, and ultrasonographic and clinical follow-up were recorded.Clinical success was obtained in 13 of 14 patients. In one patient, extrahepatic puncture of the PV occurred, resulting in hemorrhage and requiring placement of a covered stent to control the bleeding. The mean number of punctures required to access the PV was 2.6 +/- 1.7, and the total procedure time was 2.5 hours +/- 0.6. Mean fluoroscopy time was 22.3 minutes +/- 5.5. Results of clinical and ultrasonographic follow-up compare favorably to previously published reports.TIPS creation with a combination hybrid radiography/MR unit is feasible and may reduce the number of needle passes required and radiation exposure, with similar overall outcomes compared with studies reported in the literature.

    View details for DOI 10.1097/01.RVI.0000143766.08029.6E

    View details for PubMedID 15713923

  • MR-guided interventions of the breast. Magn Reson Imaging Clin N Am van den Bosch MA, Daniel BL 2005; 13 (3): 505-17
  • Breast magnetic resonance imaging alters patient selection for accelerated, partial breast irradiation 47th Annual Meeting of the American-Society-for-Therapeutic-Radiology-and-Oncology Horst, K. C., Ikeda, D. M., Birdwell, R. L., Daniel, B. L., Goffinet, D. R., Pal, S., Nowels, K. W., Dirbas, F. M. ELSEVIER SCIENCE INC. 2005: S4–S5
  • Biothermal modeling of transurethral ultrasound applicators for MR-guided prostate thermal therapy Conference on Treatment of Tissue: Energy Delivery and Assessment III Ross, A. B., Diederich, C. J., Nau, W. H., Tyreus, D., Gill, H., Bouley, D., Butts, R. K., Rieke, V., Daniel, B., Sommer, G. SPIE-INT SOC OPTICAL ENGINEERING. 2005: 220–227

    View details for DOI 10.1117/12.592491

    View details for Web of Science ID 000229738000020

  • MRI features of mucosa-associated lymphoid tissue lymphoma in the breast. AJR Am J Roentgenol Espinosa LA, Daniel BL, Jeffrey SS, Nowels KW, Ikeda DM 2005; 185 (1): 199-202
  • MRI-guided interstitial ultrasound thermal therapy of the prostate: A feasibility study in the canine model. Med Phys Nau WH, Diederich CJ, Ross AB, Butts K, Rieke V, Bouley D, Gill H, Daniel B, Sommer G 2005; 32: 733-43
  • Mapping of the prostate in endorectal coil-based MRI/MRSI and CT: A deformable registration and validation study 45th Annual Meeting of the American-Society-for-Therapeutic-Radiology-and-Oncology (ASTRO) Lian, J., Xing, L., Hunjan, S., Dumoulin, C., Levin, J., Lo, A., Watkins, R., Rohling, K., Giaquinto, R., Kim, D., Spielman, D., Daniel, B. AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS. 2004: 3087–94

    Abstract

    The endorectal coil is being increasingly used in magnetic resonance imaging (MRI) and MR spectroscopic imaging (MRSI) to obtain anatomic and metabolic images of the prostate with high signal-to-noise ratio (SNR). In practice, however, the use of endorectal probe inevitably distorts the prostate and other soft tissue organs, making the analysis and the use of the acquired image data in treatment planning difficult. The purpose of this work is to develop a deformable image registration algorithm to map the MRI/MRSI information obtained using an endorectal probe onto CT images and to verify the accuracy of the registration by phantom and patient studies. A mapping procedure involved using a thin plate spline (TPS) transformation was implemented to establish voxel-to-voxel correspondence between a reference image and a floating image with deformation. An elastic phantom with a number of implanted fiducial markers was designed for the validation of the quality of the registration. Radiographic images of the phantom were obtained before and after a series of intentionally introduced distortions. After mapping the distorted phantom to the original one, the displacements of the implanted markers were measured with respect to their ideal positions and the mean error was calculated. In patient studies, CT images of three prostate patients were acquired, followed by 3 Tesla (3 T) MR images with a rigid endorectal coil. Registration quality was estimated by the centroid position displacement and image coincidence index (CI). Phantom and patient studies show that TPS-based registration has achieved significantly higher accuracy than the previously reported method based on a rigid-body transformation and scaling. The technique should be useful to map the MR spectroscopic dataset acquired with ER probe onto the treatment planning CT dataset to guide radiotherapy planning.

    View details for DOI 10.1118/1.106292

    View details for Web of Science ID 000225372300019

    View details for PubMedID 15587662

  • Magnetic resonance imaging of suspicious breast masses seen on one mammographic view. breast journal Offodile, R. S., Daniel, B. L., Jeffrey, S. S., Wapnir, I., Dirbas, F. M., Ikeda, D. M. 2004; 10 (5): 416-422

    Abstract

    The purpose of this study was to assess the utility of contrast-enhanced breast magnetic resonance imaging (MRI) in identifying lesions unidentified on the craniocaudal projection. The authors reviewed five patients with suspicious mammographic lesions not imaged on the craniocaudal mammogram who were referred for contrast-enhanced MRI and underwent subsequent preoperative needle localization in four of the five cases. Five patients, ages 56 to 69 years, had suspicious lesions identified on mediolateral oblique (MLO) or mediolateral (ML) projections only. Ultrasound did not identify the lesion in any of these cases. MRI identified suspicious breast lesions measuring 5 to 12 mm in size. These were located high on the chest wall or in the upper inner quadrant. Suspicious lesions seen only on the MLO or ML projections may reside high on the chest wall or in the upper inner quadrant. Lesions in these locations may be typically excluded on the craniocaudal projection during mammography. Breast MRI has the advantage of imaging the entire breast and is particularly useful for these lesions. In this series, MRI prevented delay in breast cancer diagnosis.

    View details for PubMedID 15327495

  • Referenceless PRF shift thermometry MAGNETIC RESONANCE IN MEDICINE Rieke, V., Vigen, K. K., Sommer, G., Daniel, B. L., Pauly, J. M., Butts, K. 2004; 51 (6): 1223-1231

    Abstract

    The proton resonance frequency (PRF) shift provides a means of measuring temperature changes during minimally invasive thermotherapy. However, conventional PRF thermometry relies on the subtraction of baseline images, which makes it sensitive to tissue motion and frequency drift during the course of treatment. In this study, a new method is presented that eliminates these problems by estimating the background phase from each acquired image phase. In this referenceless method, a polynomial is fit to the background phase outside the heated region in a weighted least-squares fit. Extrapolation of the polynomial to the heated region serves as the background phase estimate, which is then subtracted from the actual phase. The referenceless method is demonstrated on a phantom during laser heating, 0 degrees temperature rise images of in vivo human liver, interstitial laser ablation of porcine liver, and transurethral ultrasound ablation of canine prostate. A good correlation between temperature maps reconstructed with the referenceless and subtraction methods was found.

    View details for DOI 10.1002/mrm.20090

    View details for PubMedID 15170843

  • Breast magnetic resonance image screening and ductal lavage in women at high genetic risk for breast carcinoma CANCER Hartman, A. R., Daniel, B. L., Kurian, A. W., Mills, M. A., Nowels, K. W., Dirbas, F. M., Kingham, K. E., Chun, N. M., Herfkens, R. J., Ford, J. M., Plevritis, S. K. 2004; 100 (3): 479-489

    Abstract

    Intensive screening is an alternative to prophylactic mastectomy in women at high risk for developing breast carcinoma. The current article reports preliminary results from a screening protocol using high-quality magnetic resonance imaging (MRI), ductal lavage (DL), clinical breast examination, and mammography to identify early malignancy and high-risk lesions in women at increased genetic risk of breast carcinoma.Women with inherited BRCA1 or BRCA2 mutations or women with a >10% risk of developing breast carcinoma at 10 years, as estimated by the Claus model, were eligible. Patients were accrued from September 2001 to May 2003. Enrolled patients underwent biannual clinical breast examinations and annual mammography, breast MRI, and DL.Forty-one women underwent an initial screen. Fifteen of 41 enrolled women (36.6%) either had undergone previous bilateral oophorectomy and/or were on tamoxifen at the time of the initial screen. One patient who was a BRCA1 carrier had high-grade ductal carcinoma in situ (DCIS) that was screen detected by MRI but that was missed on mammography. High-risk lesions that were screen detected by MRI in three women included radial scars and atypical lobular hyperplasia. DL detected seven women with cellular atypia, including one woman who had a normal MRI and mammogram.Breast MRI identified high-grade DCIS and high-risk lesions that were missed by mammography. DL detected cytologic atypia in a high-risk cohort. A larger screening trial is needed to determine which subgroups of high-risk women will benefit and whether the identification of malignant and high-risk lesions at an early stage will impact breast carcinoma incidence and mortality.

    View details for DOI 10.1002/cncr.11926

    View details for PubMedID 14745863

  • Highly directional transurethral ultrasound applicators with rotational control for MRI-guided prostatic thermal therapy PHYSICS IN MEDICINE AND BIOLOGY Ross, A. B., Diederich, C. J., Nau, W. H., Gill, H., Bouley, D. M., Daniel, B., Rieke, V., Butts, R. K., Sommer, G. 2004; 49 (2): 189-204

    Abstract

    Transurethral ultrasound applicators with highly directional energy deposition and rotational control were investigated for precise treatment of benign prostatic hyperplasia (BPH) and adenocarcinoma of the prostate (CaP). Two types of catheter-based applicators were fabricated, using either 90 degrees sectored tubular (3.5 mm OD x 10 mm) or planar transducers (3.5 mm x 10 mm). They were constructed to be MRI compatible, minimally invasive and allow for manual rotation of the transducer array within a 10 mm cooling balloon. In vivo evaluations of the applicators were performed in canine prostates (n = 3) using MRI guidance (0.5 T interventional magnet). MR temperature imaging (MRTI) utilizing the proton resonance frequency shift method was used to acquire multiple-slice temperature overlays in real time for monitoring and guiding the thermal treatments. Post-treatment T1-weighted contrast-enhanced imaging and triphenyl tetrazolium chloride stained tissue sections were used to define regions of tissue coagulation. Single sonications with the 90 degrees tubular applicator (9-15 W, 12 min, 8 MHz) produced coagulated zones covering an 80 degrees wedge of the prostate extending from 1-2 mm outside the urethra to the outer boundary of the gland (16 mm radial coagulation). Single sonications with the planar applicator (15-20 W, 10 min, approximately 8 MHz) generated thermal lesions of approximately 30 degrees extending to the prostate boundary. Multiple sequential sonications (sweeping) of a planar applicator (12 W with eight rotations of 30 degrees each) demonstrated controllable coagulation of a 270 degrees contiguous section of the prostate extending to the capsule boundary. The feasibility of using highly directional transurethral ultrasound applicators with rotational capabilities to selectively coagulate regions of the prostate while monitoring and controlling the treatments with MRTI was demonstrated in this study.

    View details for DOI 10.1088/0031-9155/49/2/0020

    View details for Web of Science ID 000220421700002

    View details for PubMedID 15083666

  • Highly directional transurethral ultrasound applicators with rotational control for MRI-guided prostatic thermal therapy. Phys Med Biol Ross AB, Diederich CJ, Nau WH, Gill H, Bouley DM, Daniel B, Rieke V, Butts RK, Sommer G 2004; 49 (2): 189-204
  • Using finite-element method to register endorectal coil-based MRI/MRSI with treatment planning CT images 46th Annual Meeting of the American-Society-for-Therapeutic-Radiology-and-Oncology Schreibmann, E., Kim, D., Hancock, S. L., Boyer, A., Spielman, D., Daniel, B., Xing, L. ELSEVIER SCIENCE INC. 2004: S592–S593
  • A pilot breast cancer screening trial for women at high inherited risk using clinical breast exam, mammography, breast magnetic resonance imaging, and ductal lavage: updated results after median follow-up of fourteen months. 27th Annual San Antonio Breast Cancer Symposium Kurian, A. W., Daniel, B. L., Mills, M. A., Nowels, K. W., Ford, J. M., Plevritis, S. K., Kingham, K. E., Chun, N. M., Herfkens, R. J., Dirbas, F. M., Garber, J. M., Hartman, A. R. SPRINGER. 2004: S187–S188
  • Can MRI morphological and kinetic characteristics predict locally advanced breast cancer response to neoadjuvant chemotherapy? 104th Annual Meeting of the American-Roentgen-Ray-Society Pal, S., Ikeda, D. M., Daniel, B. L., Seghal, G., Birdwell, R. L., Stables, L., Sigal, B. M., Plevritis, S. AMER ROENTGEN RAY SOC. 2004: 9–10
  • Triggered, navigated, multi-baseline method for proton resonance frequency temperature mapping with respiratory motion MAGNETIC RESONANCE IN MEDICINE Vigen, K. K., Daniel, B. L., Pauly, J. M., Butts, K. 2003; 50 (5): 1003-1010

    Abstract

    A technique is presented for the acquisition of temperature maps in the presence of variable respiratory motion using the proton resonance frequency (PRF) shift. The technique uses respiratory triggering, diaphragm position determination with a navigator echo, and the collection of multiple baseline images to generate temperature maps. Laser ablations were performed in an ex vivo liver phantom undergoing variable simulated respiratory motion and in vivo in four porcine livers, demonstrating a reduction of artifacts in the computed temperature maps compared with conventional single baseline techniques, both uncorrected and corrected for motion.

    View details for DOI 10.1002/mrm.10608

    View details for PubMedID 14587011

  • First use of a truly-hybrid X-ray/MR imaging system for guidance of brain biopsy ACTA NEUROCHIRURGICA Fahrig, R., Heit, G., Wen, Z., Daniel, B. L., Butts, K., Pelc, N. J. 2003; 145 (11): 995-997

    Abstract

    The use of a new hybrid imaging system for guidance of a brain biopsy is described. The system combines the strengths of MRI (soft-tissue contrast, arbitrary plane selection) with those of x-ray fluoroscopy (high-resolution real-time projection images, clear portrayal of bony structures) and allows switching between the imaging modalities without moving the patient. The biopsy was carried out using x-ray guidance for direction of the needle through the foramen ovale and MR guidance to target the soft-tissue lesion. Appropriate samples were acquired. The system could be particularly effective for guidance of those cases where motion, swelling, resection and other intra-operative anatomical changes cannot be accounted for using traditional stereotactic-based imaging approaches.

    View details for DOI 10.1007/s00701-003-0138-7

    View details for Web of Science ID 000186686300020

    View details for PubMedID 14628205

  • Magnetic resonance imaging of intraductal papilloma of the breast MAGNETIC RESONANCE IMAGING Daniel, B. L., Gardner, R. W., Birdwell, R. L., Nowels, K. W., Johnson, D. 2003; 21 (8): 887-892

    Abstract

    To describe the appearance of isolated intraductal papilloma on contrast-enhanced water-specific, high spatial-resolution and rapid dynamic breast MRI, a retrospective review of unilateral breast images of 15 pathologically proven papilloma was performed. MRI revealed three patterns: Four papillomas were small, smooth, enhancing masses at the posterior end of an enlarged duct, corresponding to the "small lumenal mass" appearance of papilloma known from galactography. MRI detected two of these "small lumenal mass" papillomas in patients with abnormal nipple discharge even when galactography was unsuccessful. Seven papillomas were irregular enhancing masses detected in patients without nipple discharge. None of these papillomas had specifically benign findings. All seven demonstrated rapid enhancement and three showed rim enhancement or spiculation. These "tumor-like" papillomas mimicked invasive breast cancer on MRI. Four papillomas were occult on MRI, not revealed by either contrast-enhanced MRI or fat-suppressed T(2)-weighted MRI. Intraductal papillomas present with a variable appearance on MRI ranging from occult to "small lumenal mass" papillomas to irregular rapidly enhancing lesions that cannot be distinguished from invasive cancers.

    View details for DOI 10.1016/S0730-725X(03)00192-9

    View details for Web of Science ID 000186412000008

    View details for PubMedID 14599539

  • Quality assurance for MR spectroscopic imaging-guided prostate therapy 45th Annual Meeting of the American-Association-of-Physicists-in-Medicine Hunjan, S., Kim, D., Adalsteinsson, E., Daniel, B., Dumoulin, C., Boyer, A., Spielman, D., Xing, L. AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS. 2003: 1454–54
  • Mapping of the prostate in endorectal coil-based MRI/MRSI and CT: A deformable registration and validation study 45th Annual Meeting of the American-Association-of-Physicists-in-Medicine Lian, J., Hunjan, S., Daniel, B., Lo, A., Levin, J., Cardenas, C., Dumoulin, C., Watkins, R., Rohling, K., Giaquinto, R., Boyer, A., Xing, L. AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS. 2003: 1427–27
  • Including metabolic uncertainty into proton MR spectroscopic imaging (MRSI)-guided inverse treatment planning 45th Annual Meeting of the American-Association-of-Physicists-in-Medicine Lian, J., Spielman, D., Cotrutz, C., Hunjan, S., Adalsteinsson, E., King, C., Luxton, G., Boyer, A., Kim, D., Daniel, B., Xing, L. AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS. 2003: 1384–84
  • Diffusion-weighted MRI after cryosurgery of the canine prostate. Magnetic resonance imaging. Journal of magnetic resonance imaging : JMRI Butts, K., Daniel, B. L., Chen, L., Bouley, D. M., Wansapura, J., Maier, S. E., Dumoulin, C., Watkins, R. 2003; 17 (1): 131-135

    Abstract

    To evaluate the acute lesion created by cryosurgery with diffusion-weighted magnetic resonance imaging (DWI).The appearance of the acute cryolesion was evaluated in four canine prostates DWI after they were warmed to original body temperature. The prostates were excised, stained with triphenyl tetrazolium chloride (TTC), photographed, prepared for hematoxylin and eosin (H&E) staining, and examined under a light microscope.A marked decrease in apparent diffusion coefficient of 38% was evident in the center of the previously frozen tissue, but not in all of the previously frozen tissue. Histologic results confirm differences between the iceball core and the periphery of the iceball, which have markedly different imaging characteristics on DWI.The core of the previously frozen tissue has a reduced apparent diffusion coefficient (ADC) compared to the periphery of the previously frozen tissue and previously unfrozen tissue.

    View details for PubMedID 12500282

  • Diffusion-weighted MRI after cryosurgery of the canine prostate JOURNAL OF MAGNETIC RESONANCE IMAGING Butts, K., Daniel, B. L., Chen, L. L., Bouley, D. M., Wansapura, J., Maier, S. E., Dumoulin, C., Watkins, R. 2003; 17 (1): 131-135

    Abstract

    To evaluate the acute lesion created by cryosurgery with diffusion-weighted magnetic resonance imaging (DWI).The appearance of the acute cryolesion was evaluated in four canine prostates DWI after they were warmed to original body temperature. The prostates were excised, stained with triphenyl tetrazolium chloride (TTC), photographed, prepared for hematoxylin and eosin (H&E) staining, and examined under a light microscope.A marked decrease in apparent diffusion coefficient of 38% was evident in the center of the previously frozen tissue, but not in all of the previously frozen tissue. Histologic results confirm differences between the iceball core and the periphery of the iceball, which have markedly different imaging characteristics on DWI.The core of the previously frozen tissue has a reduced apparent diffusion coefficient (ADC) compared to the periphery of the previously frozen tissue and previously unfrozen tissue.

    View details for DOI 10.1002/jmri.10227

    View details for Web of Science ID 000182657900014

  • Results from a pilot breast cancer screening trial using a combination of clincal breast exam, mammography, breast MRI, and ductal lavage in a high-risk population 26th Annual San Antonio Breast Cancer Symposium Hartman, A. R., Kurian, A., Mills, M. A., Daniel, B. L., Ford, J. M., Kingham, K. E., Chun, N. M., Nowels, K. W., Herfkens, R. J., Dirbas, F. M., Plevritis, S. K. SPRINGER. 2003: S22–S23
  • Magnetic resonance guided directional transurethral ultrasound thermal therapy Conference on Thermal Treatment of Tissue: Energy Delivery and Assessment II Ross, A. B., Diederich, C. J., Nau, W. H., Tyreus, P. D., Gill, H., Bouley, D., Butts, R. K., Rieke, V., Daniel, B., Sommer, G. SPIE-INT SOC OPTICAL ENGINEERING. 2003: 192–199
  • MR-guided conformal heating of canine prostate using interstitial applicators Conference on Thermal Treatment of Tissue: Energy Delivery and Assessment II Nau, W. H., Diederich, C. J., Ross, T., Butts, K., Rieke, V., Bouley, D., Gill, H., Daniel, B., Sommer, G. SPIE-INT SOC OPTICAL ENGINEERING. 2003: 220–226
  • Utility of 3-tesla MRSI for guiding prostate IMRT. Int J Radiat Oncol Biol Phys Hunjan S, Lian J, Dumoulin C, Levin J, Watkins R, Kim D, Adelsteinsson E, Boyer A, Spielman D, Daniel B, Xing L 2003; 57 (2 Suppl): S400-1
  • Comprehensive screening using breast MRI and ductal lavage in high-risk women. 25th San Antonio Breast Cancer Symposium Hartman, A. R., Daniel, B. L., Ford, J. M., Chun, N. M., Kingham, K. E., Mills, M. A., Grekowicz, A. M., Jacobs, C. D., Herfkens, R. J., Nowels, K. W., Dirbas, F. M., Plevritis, S. K. SPRINGER. 2002: S152–S152
  • MR imaging features of infiltrating lobular carcinoma of the breast: Histopathologic correlation AMERICAN JOURNAL OF ROENTGENOLOGY Qayyum, A., Birdwell, R. L., Daniel, B. L., Nowels, K. W., Jeffrey, S. S., Agoston, T. A., Herfkens, R. J. 2002; 178 (5): 1227-1232

    Abstract

    Our study aimed to correlate the dynamic contrast-enhanced MR appearance of infiltrating lobular carcinoma of the breast with histopathologic findings.We retrospectively reviewed the high-resolution, fat-suppressed and dynamic contrast-enhanced MR images of 13 of 20 women diagnosed with pathologically proven infiltrating lobular carcinoma of the breast. Twelve of the 13 women presented with breast symptoms and underwent mammography. Five of the women also had breast sonography. MR imaging was performed for evaluation of disease extent before the patients underwent modified radical mastectomy (n = 11) or lumpectomy (n = 2). Three experienced radiologists reviewed the MR scans. The tumor pattern types described on imaging were correlated with a detailed analysis of the pathology.We found three patterns of infiltrating lobular carcinoma on MR imaging. The tumor pattern on imaging correlated with pathologic tumor morphology. We found the following patterns of infiltrating lobular carcinoma: a solitary mass with irregular margins (n = 4) that corresponded to the same appearance at pathology; multiple lesions, either connected by enhancing strands (n = 6) or separated by nonenhancing intervening tissue (n = 2), that correlated with the pathologic appearance of noncontiguous tumor foci, with malignant cells streaming in single-file fashion in the breast stroma or small tumor aggregates separated by normal tissue; and enhancing septa only, which were correlated with the histopathologic appearance of tumor cells streaming in the breast stroma (n = 1).Infiltrating lobular carcinoma may be detected on MR imaging as solitary or multiple lesions that correspond to tumor morphology on pathologic examination. The appearance of multiple lesions or of enhancing fibroglandular breast elements on MR imaging is suggestive of infiltrating lobular carcinoma.

    View details for Web of Science ID 000175077200034

    View details for PubMedID 11959737

  • MRI imaging features of infiltrating lobular carcinoma of the breast: histopathologicic correlation. AJR Am J Roentgenol Qayyum A, Birdwell RL, Daniel BL, Nowels KW, Jeffrey SS, Agoston TA, Herfkens RJ 2002; 178 (5): 1227-32
  • Truly hybrid interventional MR/x-ray system: Investigation of in vivo applications ACADEMIC RADIOLOGY Fahrig, R., Butts, K., Wen, Z. F., Saunders, R., Kee, S. T., Sze, D. Y., Daniel, B. L., Laerum, F., Pelc, N. J. 2001; 8 (12): 1200-1207

    Abstract

    The purpose of this study was to provide in vivo demonstrations of the functionality of a truly hybrid interventional x-ray/magnetic resonance (MR) system.A digital flat-panel x-ray system (1,024(2) array of 200 microm pixels, 30 frames per second) was integrated into an interventional 0.5-T magnet. The hybrid system is capable of MR and x-ray imaging of the same field of view without patient movement. Two intravascular procedures were performed in a 22-kg porcine model: placement of a transjugular intrahepatic portosystemic shunt (TIPS) (x-ray-guided catheterization of the hepatic vein, MR fluoroscopy-guided portal puncture, and x-ray-guided stent placement) and mock chemoembolization (x-ray-guided subselective catheterization of a renal artery branch and MR evaluation of perfused volume).The resolution and frame rate of the x-ray fluoroscopy images were sufficient to visualize and place devices, including nitinol guidewires (0.016-0.035-inch diameter) and stents and a 2.3-F catheter. Fifth-order branches of the renal artery could be seen. The quality of both real-time (3.5 frames per second) and standard MR images was not affected by the x-ray system. During MR-guided TIPS placement, the trocar and the portal vein could be easily visualized, allowing successful puncture from hepatic to portal vein.Switching back and forth between x-ray and MR imaging modalities without requiring movement of the patient was demonstrated. The integrated nature of the system could be especially beneficial when x-ray and MR image guidance are used iteratively.

    View details for Web of Science ID 000172759200002

    View details for PubMedID 11770916

  • Temperature mapping of frozen tissue using eddy current compensated half excitation RF pulses MAGNETIC RESONANCE IN MEDICINE Wansapura, J. P., Daniel, B. L., Pauly, J., Butts, K. 2001; 46 (5): 985-992

    Abstract

    Cryosurgery has been shown to be an effective therapy for prostate cancer. Temperature monitoring throughout the cryosurgical iceball could dramatically improve efficacy, since end temperatures of at least -40 degrees C are required. The results of this study indicate that MR thermometry based on tissue R(*)(2) has the potential to provide this information. Frozen tissue appears as a complete signal void on conventional MRI. Ultrashort echo times (TEs), achievable with half pulse excitation and a short spiral readout, allow frozen tissue to be imaged and MR characteristics to be measured. However, half pulse excitation is highly sensitive to eddy current distortions of the slice-select gradient. In this work, the effects of eddy currents on the half pulse technique are characterized and methods to overcome these effects are developed. The methods include: 1) eddy current compensated slice-select gradients, and 2) a correction for the phase shift between the first and second half excitations at the center of the slice. The effectiveness of these methods is demonstrated in R(*)(2) maps calculated within the frozen region during cryoablation.

    View details for PubMedID 11675651

  • Freehand iMRI-guided large-gauge core needle biopsy: A new minimally invasive technique for diagnosis of enhancing breast lesions 7th Annual Meeting of the International-Society-for-Magnetic-Resonance-in-Medicine (ISMRM) Daniel, B. L., Birdwell, R. L., Butts, K., Nowels, K. W., Ikeda, D. M., Heiss, S. G., Cooper, C. R., Jeffrey, S. S., Dirbas, F. M., Herfkens, R. J. JOHN WILEY & SONS INC. 2001: 896–902

    Abstract

    The lack of reliable methods for minimally invasive biopsy of suspicious enhancing breast lesions has hindered the utilization of contrast-enhanced magnetic resonance imaging (MRI) for the detection and diagnosis of breast cancer. In this study, a freehand method was developed for large-gauge core needle biopsy (LCNB) guided by intraprocedural MRI (iMRI). Twenty-seven lesions in nineteen patients were biopsied using iMRI-guided LCNB without significant complications. Diagnostic tissue was obtained in all cases. Nineteen of the 27 lesions were subsequently surgically excised. Histopathologic analysis confirmed that iMRI-guided LCNB correctly distinguished benign lesions from malignancy in 18 of the 19 lesions. The histology revealed by core biopsy was partially discrepant with surgical biopsy in 2 of the other 19 lesions. Freehand iMRI-guided LCNB of enhancing breast lesions is promising. Larger studies are needed to determine the smallest lesion that can be sampled reliably and to precisely measure the accuracy of iMRI-guided LCNB as a minimally invasive tool to diagnose suspicious lesions found by breast MRI. J. Magn. Reson. Imaging 2001;13:896-902.

    View details for Web of Science ID 000171296500013

    View details for PubMedID 11382950

  • Potential role of magnetic resonance imaging and other modalities in ductal carcinoma in situ detection. Magnetic resonance imaging clinics of North America Ikeda, D. M., Birdwell, R. L., Daniel, B. L. 2001; 9 (2): 345-?

    Abstract

    Ductal Carcinoma In Situ (DCIS) is the earliest form of ductal cancer, with a high rate of care if treated early. This article outlines the use of breast imaging in DCIS diagnosis, including mammography, MR imaging, and nuclear medicine studies. While MR imaging and nuclear medicine show great promise in DCIS diagnosis, mammography remains the mainstay of DCIS detection by the presence of microcalcifications in early tumors on the mammogram.

    View details for PubMedID 11493424

  • A truly hybrid interventional MR/X-ray system: Feasibility demonstration 8th Annual Meeting of the ISMRM Fahrig, R., Butts, K., Rowlands, J. A., Saunders, R., Stanton, J., Stevens, G. M., Daniel, B. L., Wen, Z. F., Ergun, D. L., Pelc, N. J. JOHN WILEY & SONS INC. 2001: 294–300

    Abstract

    A system enabling both x-ray fluoroscopy and MRI in a single exam, without requiring patient repositioning, would be a powerful tool for image-guided interventions. We studied the technical issues related to acquisition of x-ray images inside an open MRI system (GE Signa SP). The system includes a flat-panel x-ray detector (GE Medical Systems) placed under the patient bed, a fixed-anode x-ray tube overhead with the anode-cathode axis aligned with the main magnetic field and a high-frequency x-ray generator (Lunar Corp.). New challenges investigated related to: 1) deflection and defocusing of the electron beam of the x-ray tube; 2) proper functioning of the flat panel; 3) effects on B0 field homogeneity; and 4) additional RF noise in the MR images. We have acquired high-quality x-ray and MR images without repositioning the object using our hybrid system, which demonstrates the feasibility of this new configuration. Further work is required to ensure that the highest possible image quality is achieved with both MR and x-ray modalities.

    View details for Web of Science ID 000171295900018

    View details for PubMedID 11169837

  • Intensity-modulated parametric mapping for simultaneous display of rapid dynamic and high-spatial-resolution breast MR imaging data RADIOGRAPHICS Agoston, A. T., Daniel, B. L., Herfkens, R. J., Ikeda, D. M., Birdwell, R. L., Heiss, S. G., Sawyer-Glover, A. M. 2001; 21 (1): 217-226

    Abstract

    Contrast material-enhanced magnetic resonance (MR) imaging of the breast has variable specificity for differentiation of breast cancer from other enhancing conditions. Two principal strategies to improve its specificity are rapid dynamic MR imaging and high-spatial-resolution MR imaging. A method was developed of combining contemporaneously acquired dynamic and high-spatial-resolution MR imaging data into a single integrated display. Whole-breast rapid dynamic data were condensed into a color map by using pharmacokinetic analysis. The pharmacokinetic results were combined with the high-spatial-resolution images with a new technique that preserves underlying morphologic details. This new method was evaluated by five radiologists for eight breast lesions, and the results were compared with those of the standard method of overlaying parametric map data. The radiologists' ratings showed a statistically significant preference for the intensity-modulated parametric map display method over the overlaid parametric display method for 10 of the 12 evaluation criteria. The new method enabled simultaneous visualization of pharmacokinetic and morphologic information, facilitated assessment of lesion extent, and improved the suppression of noise in the pharmacokinetic data. The ability to simultaneously assess both dynamic and high-spatial-resolution features may ultimately improve the specificity of breast MR imaging.

    View details for Web of Science ID 000170928100018

    View details for PubMedID 11158656

  • Temperature quantitation and mapping of frozen tissue JOURNAL OF MAGNETIC RESONANCE IMAGING Butts, K., Sinclair, J., Daniel, B. L., Wansapura, J., Pauly, J. M. 2001; 13 (1): 99-104

    Abstract

    A method was developed for quantitating the temperature within frozen tissue with the magnetic resonance (MR) parameter R2*. The pulse sequence uses half-pulse excitation and a short spiral readout to achieve echo times as short as 0.2 msec. Fiber-optic temperature sensors were inserted into bovine liver tissue. The tissue was frozen at one end while being held warm at the other end. Once steady state was reached, the parameter R2* was measured. A linear dependence of R2* on temperature was demonstrated. R2* is independent of freeze number and of the orientation of the temperature gradient with respect to the main magnetic field. Feasibility in a canine prostate during cryosurgery is demonstrated. J. Magn. Reson. Imaging 2001;13:99-104.

    View details for Web of Science ID 000171295800016

    View details for PubMedID 11169810

  • Magnetic resonance imaging of breast cancer: Clinical indications and breast MRI reporting system JOURNAL OF MAGNETIC RESONANCE IMAGING Ikeda, D. M., Baker, D. R., Daniel, B. L. 2000; 12 (6): 975-983

    Abstract

    Magnetic resonance imaging (MRI) is well suited to the investigation of breast cancer by virtue of its noninvasive nature and its multiplanar imaging abilities. MRI investigations showed high sensitivity but modest specificity for breast cancer detection and diagnosis. Most early studies tested the ability of MRI to evaluate and diagnose findings in the breast discovered by other imaging tests or by breast physical examination (1-4). When it was discovered that MRI identified small breast cancers undetected by mammography or breast ultrasound, MRI was used to estimate breast cancer extent in known cancer cases for surgical planning (5,6). These investigations led to the use of MRI in a multitude of breast imaging applications, raising further questions about the use of MRI in everyday practice: What are the indications for breast MRI in general practice? What is its role in light of other imaging tests? What are its benefits and limitations in each setting? How do I report these studies? The purpose of this article is to review the clinical background regarding indications for the use of MRI and relevant cases in which MRI can impact patient management in breast disease, and to describe new developments in reporting breast MRI studies. J. Magn. Reson. Imaging 2000;12:975-983.

    View details for Web of Science ID 000171295600024

    View details for PubMedID 11105039

  • Single-shot fluid attenuated inversion recovery (FLAIR) magnetic resonance imaging of the bladder JOURNAL OF MAGNETIC RESONANCE IMAGING Daniel, B. L., Shimakawa, A., Blum, M. R., Herfkens, R. J. 2000; 11 (6): 673-677

    Abstract

    The purpose of this study was to reduce artifacts and increase imaging speed in fluid-attenuated inversion recovery (FLAIR) imaging of the urinary bladder. An existing half-Fourier, single-shot fast spin-echo imaging sequence was modified to allow presaturation with a non-slice-selective inversion recovery pulse (NSI SSFLAIR). Four independent, blinded readers rated severity of bladder artifacts and image quality in six normal male volunteers. NSI SSFLAIR effectively suppressed bladder urine signal in all six cases using a TI of 2900-3100 msec. Although NSI SSFLAIR images were noisier than standard fast spin-echo images, imaging time was only 10 seconds per slice location. Furthermore, perceived image sharpness was only minimally reduced, and conspicuity of the seminal vesicles and peripheral zone of the prostate were nearly equivalent. NSI SSFLAIR provides rapid T2-weighted imaging of the bladder wall and perivesicular tissues with nearly complete negation of signal from urine in the bladder.

    View details for PubMedID 10862067

  • Intraprocedural magnetic resonance imaging-guided interventions in the breast. Topics in magnetic resonance imaging Daniel, B. L. 2000; 11 (3): 184-190

    Abstract

    Despite the proven high sensitivity of magnetic resonance imaging (MRI) for invasive breast cancer, MRI has lagged behind mammography and sonography as an imaging modality for guiding interventional procedures because of the lack of suitable techniques. New imaging apparatuses, pulse sequences, and MR-compatible devices are beginning to enable MRI-guided breast interventions, including preoperative lesion localization and minimally invasive biopsy. MR-guided tumor ablation holds promise as a future therapy for breast cancer because of the ability of MRI to reveal the progress of heating and freezing, as well as the extent of ablated tissue.

    View details for PubMedID 11145210

  • The use of view angle tilting to reduce distortions in magnetic resonance imaging of cryosurgery MAGNETIC RESONANCE IMAGING Daniel, B. L., Butts, K. 2000; 18 (3): 281-286

    Abstract

    Susceptibility artifacts from magnetic resonance (MR)-compatible cryoprobes can distort MR images of iceballs. In this work, we investigate the ability of view angle tilting (VAT) to correct susceptibility induced distortions in MR images of cryosurgery. The efficacy of VAT was tested in an ex vivo bovine liver model of cryosurgery using MR-compatible cryoprobes. Artifacts on high bandwidth fast spin echo images of freezing obtained with and without VAT were compared with photographs of the actual iceball shape and size. In vivo imaging with VAT was demonstrated during percutaneous MR-guided cryosurgery of pig liver and brain. VAT was most successful in reducing probe and iceball distortions when the imaging plane was normal to the cryoprobe, and the cryoprobe was perpendicular to the main magnetic field of the scanner. VAT had the greatest benefit when used to correct MR images of freezing when the surface of the iceball was relatively near to the cryoprobe. For large iceballs, the artifact was small so the VAT correction was less important. We conclude that VAT significantly reduced distortions in the shape of the signal void corresponding to the extent of freezing visualized during MR-guided cryosurgery. This improved ability to visualize the exact location of the cryoprobe, as well as the precise shape of the iceball, particularly during initial freezing when the iceball is small, has potential to significantly improve the accuracy of MR-guided cryosurgery of small lesions, and the accuracy of MR-assisted temperature calculations that are based on precise imaging of the probe location, and boundary geometry of the iceball.

    View details for Web of Science ID 000086585100008

    View details for PubMedID 10745137

  • Dynamic breast MRI with spiral trajectories: 3D versus 2D JOURNAL OF MAGNETIC RESONANCE IMAGING Yen, Y. F., Han, K. F., Daniel, B. L., Heiss, S., Birdwell, R. L., Herfkens, R. J., Sawyer-Glover, A. M., Glover, G. H. 2000; 11 (4): 351-359

    Abstract

    A three-dimensional (3)D spiral sequence was developed for dynamic breast magnetic resonance (MR) imaging with much improved image quality. Partial Z phase encoding was applied to obtain thinner slices for a coverage of the whole breast. Comparison between the 3D and a previously developed multi-slice 2D spiral sequences was performed on ten healthy volunteers without contrast and five breast patients with gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA). The 3D spiral images had significantly less off-resonance blurring and spiral artifacts. With a small compromise on temporal resolution (7.7 seconds in 2D and 10.6 seconds in 3D), we obtained 32 interpolated 3-5 mm slices (with 20 Z phase encodes) for a full coverage of 10-16 cm breast with the same 1 x 1 mm2 in-plane resolution as the 2D sequence, which had 12 8-13 mm slices. Contrast between glandular and soft tissue in normal breasts was increased by about 25%. The reduced repetition time in the 3D spiral acquisition led to an increased Gd-enhanced signal. The difference between the enhancement of malignant and benign lesions increased by sevenfold. We expect that this new development could lead to improved specificity in characterizing breast lesions using MR imaging.

    View details for Web of Science ID 000087572700002

    View details for PubMedID 10767063

  • Characterization of breast lesion morphology with delayed 3DSSMT: An adjunct to dynamic breast MRI JOURNAL OF MAGNETIC RESONANCE IMAGING Leong, C. S., Daniel, B. L., Herfkens, R. J., Birdwell, R. L., Jeffrey, S. S., Ikeda, D. M., Sawyer-Glover, A. M., Glover, G. H. 2000; 11 (2): 87-96

    Abstract

    The purpose of the study was to determine the sensitivity and specificity of various morphologic criteria in distinguishing malignant from benign breast lesions using a new sequence (3DSSMT) performed immediately after dynamic breast MRI. 3DSSMT combines a water-selective spectral-spatial excitation and an on-resonance magnetization transfer pulse with three-dimensional spoiled gradient-echo imaging. Morphologic features of 87 pathologically confirmed lesions were analyzed. The presence of either skin thickening, or a combination of a spiculated or microlobulated border, with a rim, ductal, linear, or clumped enhancement pattern was 94% specific and 54% sensitive for malignancy. Conversely, the presence of either a perfectly smooth border, a well-defined margin, non-enhancing internal septations, or a macrolobulated border was 97% specific and 35% sensitive for a benign diagnosis. In conclusion, delayed 3DSSMT discriminates a significant number of benign and malignant breast lesions; it has the potential to improve the diagnostic accuracy of dynamic breast MRI.

    View details for Web of Science ID 000086078100003

    View details for PubMedID 10713939

  • Potential Role of Magnetic Resonance Imaging and Other Modalities In Ductal Carcinoma In Situ Detection. Semin Breast Dis Ikeda DM, Birdwell RL, Daniel BL 2000; 3 (1): 50-60
  • Dynamic breast MRI with spiral trajectories: 3D versus 2D. J Magn Reson Imaging Yen YF, Han K, Daniel BL, Heiss S, Birdwell RL, Herfkens RJ, Sawyer-Glover AM, Glover GH 2000; 11 (4): 351-9
  • Contrast-enhanced Magnetic Resonance Imaging of Breast Cancer. Journal of Women's Imaging Ikeda DM, Daniel BL, Birdwell RL 2000; 2 (1): 31-8
  • Diagnostic yield of MR-guided liver biopsies compared with CT- and US-guided liver biopsies 1999 SCVIR Annual Meeting Schmidt, A. J., Kee, S. T., Sze, D. Y., Daniel, B. L., Razavi, M. K., Semba, C. P., Dake, M. D. ELSEVIER SCIENCE INC. 1999: 1323–29

    Abstract

    To compare diagnostic yield and complication rates of magnetic resonance (MR)-guided versus computed tomography (CT)- and ultrasound (US)-guided liver biopsies.MR-, CT-, and US-guided liver biopsies performed between 9/96 and 9/98 were compared. Sixty patients (21 men and 39 women, mean age 60 years) underwent MR-guided biopsy of liver lesions. Thirty patients (16 men and 14 women, mean age 59 years) underwent CT-guided biopsy. Eighteen patients (seven men and 11 women, mean age 50 years) underwent US-guided biopsy. MR procedures were performed in an open-configuration 0.5-T Signa SP MR unit. Lesion localization used standard T1 and T2 sequences, whereas biopsies were performed with multiplanar spoiled gradient recalled echo and fast gradient recalled echo sequences. A coaxial system with an MR-compatible 18-gauge stabilizing needle and a 21-gauge aspiration needle was used to obtain all samples. In CT and US procedures, a 19-gauge stabilizing needle and a 21-gauge aspiration or a 20-gauge core biopsy needle were used. A cytotechnologist was present to determine the adequacy of samples.MR had a diagnostic yield of 61%. CT and US had diagnostic yields of 67% and 61%, respectively. No serious complications were reported for MR and US procedures. Two CT biopsies resulted in postprocedural hemorrhage. One patient required surgical exploration and died.MR-guided biopsy of liver lesions with use of a 0.5-T open-configuration magnet is safe and accurate when compared with CT and US. No statistical difference was observed between the diagnostic yield of biopsies performed with MR, CT, and US guidance. MR enabled biopsy of a number of lesions in the hepatic dome and lesions with low contrast, which would normally be difficult to sample safely with use of CT or US.

    View details for Web of Science ID 000083881500004

    View details for PubMedID 10584646

  • Radiofrequency ablation of breast cancer - First report of an emerging technology ARCHIVES OF SURGERY Jeffrey, S. S., Birdwell, R. L., Ikeda, D. M., Daniel, B. L., Nowels, K. W., Dirbas, F. M., Griffey, S. M. 1999; 134 (10): 1064-1068

    Abstract

    Radiofrequency (RF) energy applied to breast cancers will result in cancer cell death.Prospective nonrandomized interventional trial.A university hospital tertiary care center.Five women with locally advanced invasive breast cancer, aged 38 to 66 years, who were undergoing surgical resection of their tumor. One patient underwent preoperative chemotherapy and radiation therapy, 3 patients received preoperative chemotherapy, and 1 had no preoperative therapy. All patients completed the study.While patients were under general anesthesia and just before surgical resection, a 15-gauge insulated multiple-needle electrode was inserted into the tumor under sonographic guidance. Radiofrequency energy was applied at a low power by a preset protocol for a period of up to 30 minutes. Only a portion of the tumor was treated to evaluate the zone of RF ablation and the margin between ablated and nonablated tissue. Immediately after RF ablation, the tumor was surgically resected (4 mastectomies, 1 lumpectomy). Pathologic analysis included hematoxylin-eosin staining and enzyme histochemical analysis of cell viability with nicotinamide adenine dinucleotide-diaphorase (NADH-diaphorase) staining of snap-frozen tissue to assess immediate cell death.Cancer cell death as visualized on hematoxylin-eosin-stained paraffin section and NADH-diaphorase cell viability stains.There was evidence of cell death in all patients. Hematoxylin-eosin staining showed complete cell death in 2 patients. In 3 patients there was a heterogeneous pattern of necrotic and normal-appearing cells within the ablated tissue. The ablated zone extended around the RF electrode for a diameter of 0.8 to 1.8 cm. NADH-diaphorase cell viability stains of the ablated tissue showed complete cell death in 4 patients. The fifth patient had a single focus of viable cells (<1 mm) partially lining a cyst. There were no perioperative complications related to RF ablation.Intraoperative RF ablation results in invasive breast cancer cell death. Based on this initial report of the use of RF ablation in breast cancer, this technique merits further investigation as a percutaneous minimally invasive modality for the local treatment of breast cancer.

    View details for Web of Science ID 000083020900010

    View details for PubMedID 10522847

  • Glenohumeral relationships during physiologic shoulder motion and stress testing: Initial experience with open MR imaging and active imaging-plane registration RADIOLOGY Beaulieu, C. F., Hodge, D. K., Bergman, A. G., Butts, K., Daniel, B. L., Napper, C. L., Darrow, R. D., Dumoulin, C. L., Herfkens, R. J. 1999; 212 (3): 699-705

    Abstract

    To test the hypotheses that open dynamic magnetic resonance (MR) imaging can (a) be used to evaluate and define normal shoulder motion in active joint motion and muscle contraction and (b) be used in conjunction with physical examination.With an open-configuration, 0.5-T MR imaging system and active image-plane tracking, 10 shoulders were studied in five asymptomatic subjects to establish normal patterns of glenohumeral motion during abduction and adduction and internal and external rotation. Preliminary studies of physical examination during MR imaging, in which a physician examiner applied mechanical force to the humeral head, were also performed.During abduction and adduction and internal and external rotation maneuvers with active subjects muscle contraction, the humeral head remained precisely centered on the glenoid fossa in all asymptomatic subjects, which is in agreement with findings of previous radiographic studies. Application of force to the humeral head by an examiner was associated with as much as 6 mm of anterior translation and 13 mm of posterior translation.Dynamic MR imaging of the glenohumeral joint is possible over a wide range of physiologic motion in vertically open systems. Use of an MR tracking coil enabled accurate tracking of the anatomy of interest. These preliminary measurements of normal glenohumeral motion patterns begin to establish normal ranges of motion and constitute a necessary first step in characterizing pathologic motion in patients with common clinical problems such as instability and impingement.

    View details for PubMedID 10478235

  • Joint motion in an open MR unit using MR tracking JOURNAL OF MAGNETIC RESONANCE IMAGING Pearle, A. D., Daniel, B. L., Bergman, A. G., Beaulieu, C. F., Lang, P., Dumoulin, C. L., Darrow, R. D., Norbash, A. M., Napper, C. L., Hurtak, W., Butts, K. 1999; 10 (1): 8-14

    Abstract

    A system for active scan plane guidance during kinematic magnetic resonance (MR) examination of joint motion was developed utilizing an external tracking coil and MR tracking software. In a phantom study and during upright, weight-bearing, physiologic knee flexion, the external tracking coil maintained the scan plane through desired structures. Thus, MR tracking provides a robust method to guide the scan plane during MR imaging of active joint motion.

    View details for Web of Science ID 000081199600002

    View details for PubMedID 10398972

  • 1999 Gary J. Becker Young Investigator Award. MR-guided transjugular portosystemic shunt placement in a swine model. Journal of vascular and interventional radiology Kee, S. T., Rhee, J. S., Butts, K., Daniel, B., Pauly, J., Kerr, A., O'Sullivan, G. J., Sze, D. Y., Razavi, M. K., Semba, C. P., Herfkens, R. J., Dake, M. D. 1999; 10 (5): 529-535

    Abstract

    To evaluate the performance of portal venous puncture with use of magnetic resonance (MR) guidance, and to place a transjugular intrahepatic portosystemic shunt (TIPS) in a swine model.A study of 12 swine was performed to evaluate the ability of interventional MR imaging to guide portal vein puncture and TIPS placement. Six swine had catheters placed in the right hepatic vein under C-arm fluoroscopy. A nitinol guide wire was left in the vein and the animals were then moved into an open configuration MR imaging unit. A TIPS needle set was used to puncture the portal vein using MR fluoroscopy. The animals were transferred to the C-arm, and venography confirmed portal vein puncture. A follow-up study was performed in six additional swine to place a TIPS using only MR imaging guidance. MR tracking was used to advance a catheter from the right atrium into the inferior vena cava. Puncture of the portal vein was performed and a nitinol stent was placed, bridging the hepatic parenchyma. MR venogram confirmed placement.Successful portal vein puncture was achieved in all animals. The number of punctures required decreased from 12 in the first animal to a single puncture in the last eight swine. A stent was successfully placed across the hepatic tract in all six swine.Real-time MR imaging proved to be a feasible method to guide portal vein puncture and TIPS placement in pigs.

    View details for PubMedID 10357476

  • MR-guided transjugular portosystemic shunt placement in a swine model JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kee, S. T., Rhee, J. S., Butts, K., Daniel, B., Pauly, J., Kerr, A., O'Sullivan, G. J., Sze, D. Y., Razavi, M. K., Semba, C. P., Herfkens, R. J., Dake, M. D. 1999; 10 (5): 529-535

    Abstract

    To evaluate the performance of portal venous puncture with use of magnetic resonance (MR) guidance, and to place a transjugular intrahepatic portosystemic shunt (TIPS) in a swine model.A study of 12 swine was performed to evaluate the ability of interventional MR imaging to guide portal vein puncture and TIPS placement. Six swine had catheters placed in the right hepatic vein under C-arm fluoroscopy. A nitinol guide wire was left in the vein and the animals were then moved into an open configuration MR imaging unit. A TIPS needle set was used to puncture the portal vein using MR fluoroscopy. The animals were transferred to the C-arm, and venography confirmed portal vein puncture. A follow-up study was performed in six additional swine to place a TIPS using only MR imaging guidance. MR tracking was used to advance a catheter from the right atrium into the inferior vena cava. Puncture of the portal vein was performed and a nitinol stent was placed, bridging the hepatic parenchyma. MR venogram confirmed placement.Successful portal vein puncture was achieved in all animals. The number of punctures required decreased from 12 in the first animal to a single puncture in the last eight swine. A stent was successfully placed across the hepatic tract in all six swine.Real-time MR imaging proved to be a feasible method to guide portal vein puncture and TIPS placement in pigs.

    View details for Web of Science ID 000084345500001

  • Management of biopsy needle artifacts: Techniques for RF-refocused MRI JOURNAL OF MAGNETIC RESONANCE IMAGING Butts, K., Pauly, J. M., Daniel, B. L., Kee, S., Norbash, A. M. 1999; 9 (4): 586-595

    Abstract

    Several methods were investigated to improve the depiction of biopsy needles in radiofrequency (RF)-refocused magnetic resonance imaging. Distortion correction is performed by the use of view angle tilting (VAT): a gradient is employed on the slice-select axis during readout. Needle conspicuity is increased by offsetting the gradient echo from the spin echo and by inverting the 90 degrees RF pulse slice-select gradient. VAT effectively re-registers in-plane shifts. Since this method changes the projection angle through the slice, some structures appear blurred, while other structures appear sharper. VAT does not correct errors in slice selection. Offsetting the spin echo from the gradient echo increases needle conspicuity but can result in a shift in the apparent location of the needle. Inverting the 90 degrees slice-select gradient effectively increases the needle conspicuity with no shift in the needle location. These methods provide an easy and interactive means to manipulate needle artifacts but should be used cautiously.

    View details for Web of Science ID 000080145000013

    View details for PubMedID 10232519

  • Magnetic resonance imaging of frozen tissues: Temperature-dependent MR signal characteristics and relevance for MR monitoring of cryosurgery MAGNETIC RESONANCE IN MEDICINE Daniel, B. L., Butts, K., Block, W. F. 1999; 41 (3): 627-630

    Abstract

    Previously, the magnetic resonance (MR) imaging appearance of frozen tissues created during cryosurgery has been described as a signal void. In this work, very short echo times (1.2 msec) allowed MR signals from frozen tissues to be measured at temperatures down to -35 degrees C. Ex vivo bovine liver, muscle, adipose tissue, and water were imaged at steady-state temperatures from -78 degrees to +6 degrees C. Signal intensity, T2*, and T1 were measured using gradient-echo imaging. Signal intensity and T2* decrease monotonically with temperature. In the future, these MR parameters may be useful for mapping temperatures during cryosurgery.

    View details for PubMedID 10204889

  • Images in clinical medicine. Mammographically occult breast cancer. New England journal of medicine Daniel, B. L. 1999; 340 (5): 358-?

    View details for PubMedID 9929526

  • Differentiation of hepatic malignancies from hemangiomas and cysts by T2 relaxation times: Early experience with multiply refocused four-echo imaging at 1.5 T JOURNAL OF MAGNETIC RESONANCE IMAGING Olcott, E. W., Li, K. C., Wright, G. A., Pattarelli, P. P., Katz, D. S., Ch'en, I. Y., Daniel, B. L. 1999; 9 (1): 81-86

    Abstract

    The purpose of this study was to examine hepatic lesions with a sequence designed to yield improved T2 measurements and evaluate the clinical utility of these measurements in distinguishing malignant from benign disease. Using a modified Carr-Purcell sequence incorporating features designed to compensate for imperfections in the imaging system, including a train of refocusing pulses emitted in an MLEV pattern oriented in composite fashion along all three coordinate axes, and a single spatially selective pulse placed immediately before a spiral readout, 14 benign lesions and 13 malignant lesions were evaluated prospectively with a conventional 1.5 T imager. The maximum, minimum, and mean T2 values of malignant lesions, hemangiomas, and cysts exceeded corresponding published values from spin-echo and echoplanar studies. The mean T2 value of the malignant lesions differed significantly (P < 0.0001) from those of hemangiomas and cysts. All malignant lesions and all benign lesions were distinguishable by their T2 values, which had ranges of no greater than 118.6 msec and no less than 134.3 msec, respectively. This early experience suggests that improved T2 measurements can facilitate the differentiation of hepatic malignancies from hemangiomas and cysts.

    View details for Web of Science ID 000080144300011

    View details for PubMedID 10030654

  • Glenohumeral relationships during physiological shoulder motion: initial experience with open MRI and active scan-plane registration. Radiology Beaulieu C, Hodge D, Bergman G, Butts K, Daniel B, Napper C, Dumoulin C, Herfkens R 1999; 212: 699-705
  • Real-time interactive MRI on an open MRI system. RSNA EJ (http://ej.rsna.org/ej3/0109-99.fin/index.html) Butts K, Pauly J, Kerr A, Daniel BL, Kee S 1999; 3
  • Breast disease: Dynamic spiral MR imaging 82nd Scientific Assembly and Annual Meeting of the Radiological-Society-of-North-America Daniel, B. L., Yen, Y. F., Glover, G. H., Ikeda, D. M., Birdwell, R. L., Sawyer-Glover, A. M., Black, J. W., Plevritis, S. K., Jeffrey, S. S., Herfkens, R. J. RADIOLOGICAL SOC NORTH AMERICA. 1998: 499–509

    Abstract

    To compare various subjective, empiric, and pharmacokinetic methods for interpreting findings at dynamic magnetic resonance (MR) imaging of the breast.Dynamic spiral breast MR imaging was performed in 52 women suspected of having or with known breast disease. Gadolinium-enhanced images were obtained at 12 locations through the whole breast every 7.8 seconds for 8.5 minutes after bolus injection of contrast material. Time-signal intensity curves from regions of interest corresponding to 57 pathologically proved lesions were analyzed by means of a two-compartment pharmacokinetic model, and the diagnostic performance of various parameters was analyzed.Findings included invasive carcinoma in 17 patients, isolated ductal carcinoma in situ (DCIS) in six, and benign lesions in 34. Although some overlap between carcinomas and benign diagnoses was noted for all parameters, receiver operating characteristic analysis indicated that the exchange rate constant had the greatest overall ability to discriminate benign and malignant disease. The elimination rate constant and washout were the most specific parameters. The exchange rate constant, wash-in, and extrapolation point were the most sensitive parameters. DCIS was not consistently distinguished from benign disease with any method.Dynamic spiral breast MR imaging proved an excellent method with which to collect contrast enhancement data rapidly enough that accurate comparisons can be made between many analytic methods.

    View details for PubMedID 9807580

  • Detection of colonic polyps in a phantom model: Implications for virtual colonoscopy data acquisition JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Beaulieu, C. F., Napel, S., Daniel, B. L., Ch'en, I. Y., Rubin, G. D., Johnstone, I. M., Jeffrey, R. B. 1998; 22 (4): 656-663

    Abstract

    Virtual colonoscopy is a new method of colon examination in which computer-aided 3D visualization of spiral CT simulates fiberoptic colonoscopy. We used a colon phantom containing various-sized spheres to determine the influence of CT acquisition parameters on lesion detectability and sizing.Spherical plastic beads with diameters of 2.5, 4, 6, 8 and 10 mm were randomly attached to the inner wall of segments of plastic tubing. Groups of three sealed tubes were scanned at 3/1, 3/2, 5/1 collimation (mm)/pitch settings in orientations perpendicular and parallel to the scanner gantry. For each acquisition, image sets were reconstructed at intervals from 0.5 to 5.0 mm. Two blinded reviewers assessed transverse cross-sections of the phantoms for bead detection, using source CT images for images for acquisitions obtained with the tubes oriented perpendicular to the gantry and using orthogonal reformatted images for scans oriented parallel to the gantry.Detection of beads of > or = 4 mm was 100% for both tube orientations and for all collimator/pitch settings and reconstruction intervals. For the 2.5 mm beads, detection decreased to 78-94% for 5 mm collimation/pitch 2 scans when the phantom sections were oriented parallel to the gantry (p = 0.01). Apparent elongation of beads in the slice direction occurred as the collimation and pitch increased. The majority of the elongation (approximately 75%) was attributable to changing the collimator from 3 to 5 mm, with the remainder of the elongation due to doubling the pitch from 1 to 2.CT scanning at 5 mm collimation and up to pitch 2 is adequate for detection of high contrast lesions as small as 4 mm in this model. However, lesion size and geometry are less accurately depicted than at narrower collimation and lower pitch settings.

    View details for Web of Science ID 000074812400028

    View details for PubMedID 9676463

  • Breast lesion localization: A freehand, interactive MR imaging-guided technique RADIOLOGY Daniel, B. L., Birdwell, R. L., Ikeda, D. M., Jeffrey, S. S., Black, J. W., Block, W. F., Sawyer-Glover, A. M., Glover, G. H., Herfkens, R. J. 1998; 207 (2): 455-463

    Abstract

    To evaluate interactive magnetic resonance (MR) imaging-guided preoperative needle localization and hookwire placement in the noncompressed breast in patients in the prone position.Nineteen MR imaging-guided breast lesion localization procedures were performed in 17 patients aged 38-70 years (mean age, 48 years) by using an open-platform breast coil in either a 1.5-T, closed-bore imager (n = 14) or a 0.5-T, open-bore imager (n = 5). Rapid imaging (fast spin-echo, water-selective fast spin-echo, or water-specific three-point Dixon gradient-echo) was alternated with freehand manipulation of an MR-compatible needle to achieve accurate needle placement.Up to three manipulations of the needle were required during an average of 9 minutes to reach the target lesion. MR imaging findings confirmed the final needle position within 9 mm of the target in all cases. The accuracy of 10 localizations was independently corroborated either at mammography or at ultrasonography. Nine lesions were visible on MR images only.Interactive MR imaging-guided, freehand needle localization is simple, accurate, and requires no special stereotactic equipment. Lesions throughout the breast, including those in the anterior part of the breast and those near the chest wall, which can be inaccessible with standard grid or compression-plate techniques, can be localized. A variety of needle trajectories in addition to the horizontal path are possible, including circumareolar approaches and tangential needle paths designed to avoid puncture of implants.

    View details for Web of Science ID 000073204300031

    View details for PubMedID 9577495

  • Breast cancer: Gadolinium-enhanced MR imaging with a 0.5-T open imager and three-point Dixon technique RADIOLOGY Daniel, B. L., Butts, K., Glover, G. H., Cooper, C., Herfkens, R. J. 1998; 207 (1): 183-190

    Abstract

    To investigate the three-point Dixon technique as a method for obtaining fat-nulled images of contrast material-enhancing breast lesions with a 0.5-T open magnetic resonance (MR) imager.Real and imaginary source images were obtained with an interleaved gradient-echo sequence with a repetition time of 550 msec and echo times of 12.8, 19.8, and 26.8 msec. Twenty-four to 28 sections were obtained in the sagittal plane with a 90 degrees flip angle, 256 x 192 matrix, 3-4.5-mm section thickness, and acquisition time of 10 minutes 54 seconds. A three-point Dixon reconstruction algorithm was used to generate water-specific, fat-specific, and combined images from the raw image data. Twelve breasts in 10 patients and one healthy volunteer were imaged.Three-point Dixon images were superior to extended two-point Dixon and fat-suppressed images and to images generated by means of subtraction of three-dimensional fast spoiled gradient-echo images obtained before contrast material injection from those obtained after.Three-point Dixon imaging provides a robust method for creating fat-nulled images of enhancing breast lesions in the 0.5-T open MR environment. Water-specific three-point Dixon images are successful in regions of B0 heterogeneity and are superior to fat-suppressed images. They are much less susceptible to motion artifact than are subtraction images.

    View details for PubMedID 9530315

  • Three-dimensional shaded-surface rendering of MR images of the breast: technique, applications, and impact on surgical management of breast disease. Radiographics Daniel, B. L., Jeffrey, S. S., Birdwell, R. L., Ikeda, D. M., Sawyer-Glover, A. M., Herfkens, R. J. 1998; 18 (2): 483-496

    Abstract

    Contrast material-enhanced magnetic resonance (MR) imaging is reported to be the most accurate modality for determining the extent of breast cancer before surgery. Three-dimensionally rendered MR images can be used as an adjunct in planning breast surgery. Semiautomated methods are used to isolate the breast tissue within high-resolution MR images and to render the skin with a shaded-surface method. Cut-away views reveal lesions in the interior of the breast. Cut-plane shaded-surface display provides the surgeon with information on the size, extent, and spatial relationships of a breast lesion in a simple, intuitive format. This technique can help the surgeon plan a breast biopsy, lumpectomy, or mastectomy that will maximize local control of breast cancer while minimizing cosmetic damage to the unaffected portions of the breast. In a review of 15 clinical cases, cut-plane shaded-surface rendering aided surgical planning in 10 cases.

    View details for PubMedID 9536491

  • Shaded-surface rendering of MR images of the breast: Technique, applications, and impact on surgical management of breast disease RADIOGRAPHICS Daniel, B. L., Jeffrey, S. S., Birdwell, R. L., Ikeda, D. M., Sawyer-Glover, A. M., Herfkens, R. J. 1998; 18 (2): 483-496
  • Interactive MR-guided, 14-gauge core-needle biopsy of enhancing lesions in a breast phantom model ACADEMIC RADIOLOGY Daniel, B. L., Birdwell, R. L., Black, J. W., Ikeda, D. M., Glover, G. H., Herfkens, R. J. 1997; 4 (7): 508-512

    Abstract

    The authors attempted to determine the accuracy of magnetic resonance (MR) imaging-guided core-needle biopsy performed with a titanium biopsy needle in a breast phantom.Eight 6-7-mm lesions were created at random positions in a lard breast phantom. Each 0.2-mL lesion contained 0.118 mg of gadopentetate dimeglumine, 0.0025 mL of methylene blue dye, and 23.8 mg of gelatin. Rapid fast spin-echo MR imaging was used to guide placement of a 14-gauge titanium core-biopsy needle. A 1.5-T MR imager was used with an open-platform phased-array breast coil.Visualization of blue dye in core specimens confirmed successful biopsy in 16 of 16 attempts. One (n = 13) or two (n = 3) passes through the "skin" of the phantom were necessary for biopsy. The needle trajectory was adjusted less than three times for each pass through the "skin" in 15 of 16 biopsies. Cores that contained lesion material were obtained in the first sample in 15 of 16 biopsies. On T1-weighted images, needles cast 7-mm-diameter artifacts.MR imaging can be used accurately to guide core-needle biopsy of 6-7-mm lesions in a breast phantom.

    View details for Web of Science ID A1997XG51800009

    View details for PubMedID 9232171

  • Do arterial phase helical CT images improve detection or characterization of colorectal liver metastases? JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Chen, I. Y., Katz, D. S., Jeffrey, R. B., Daniel, B. L., Li, K. C., Beaulieu, C. F., Mindelzun, R. E., Yao, D., Olcott, E. W. 1997; 21 (3): 391-397

    Abstract

    Our goal was to determine if arterial phase images from dual phase helical CT improve either the detection or the characterization of hepatic metastases in patients with colorectal carcinoma. Sixty-two patients with known colorectal cancer underwent 65 dual phase helical CT examinations to evaluate for possible liver metastases. Three blinded reviewers independently evaluated the portal venous phase images alone to determine if hepatic metastases were present or absent. Arterial phase images were then analyzed to determine if they identified additional lesions or aided in characterizing small hepatic lesions. Scores of the two methods for diagnosing metastases were compared with the "gold standard" established by a consensus panel of three other radiologists who reviewed all images together with clinical, pathologic, and other imaging data. The addition of arterial phase imaging did not detect any new metastases. However, in 6 of the 64 technically adequate examinations, hepatic arterial phase images increased lesion conspicuity and significantly increased diagnostic confidence when compared with portal vein phase scans alone. In patients with colorectal cancer, the addition of arterial phase imaging does not increase sensitivity, but improves the specificity in diagnosing liver metastases in a small number of cases. Dual phase helical CT does not appear to be indicated in the evaluation of liver metastases from colorectal cancer.

    View details for Web of Science ID A1997WV86400010

    View details for PubMedID 9135646

  • Image quality in lossy compressed digital mammograms. Signal Processing Perlmutter SM, Cosman PC, Gray RM, Olshen RA, Ikeda D, Adams CN, Betts BJ, Williams M, Perlmutter KO, Li J, Aiyer A, Fajardo L, Birdwell R, Daniel BL 1997; 59 (2): 189-210
  • Do arterial phase helical CT images improve detection or characterization of colorectal liver metastases? J Comput Assist Tomogr Ch'en IY, Katz DS, Jeffrey RB, Daniel BL, Li KC, Beaulieu CF, Mindelzun RE, Yao D, Olcott EW 1997; 21 (3): 391-7
  • Immunity and morbidity in schistosomiasis japonicum infection. Am J Trop Med Hyg Olds GR, Olveda R, Wu G, Wiest P, McGarvey S, Aligui G, Zhang S, Ramirez B, Daniel B, Peters P, Romulo R, Fevidal P, Tiu W, Yuan J, Domingo E, Blas B 1996; 55 (5 Suppl): 121
  • Evaluating quality and utility of digital mammograms and lossy compressed digital mammograms 3rd International Workshop on Digital Mammography Adams, D. N., Aiyer, A., Betts, B. J., Li, J., Cosman, P. C., Perlmutter, S. M., Williams, M., Perlmutter, K. O., Ikeda, D., Fajardo, L., Birdwell, R., Daniel, B. L., Rossiter, S., Olshen, R. A., Gray, R. M. ELSEVIER SCIENCE PUBL B V. 1996: 169–176
  • The hemodynamics of transjugular intrahepatic portosystemic shunts: investigations with Doppler sonography and development of an in vitro model. Acad Radiol Daniel BL, Rubin JM, Fowlkes BJ, Williams DM, Adler RA 1996; 3 (6): 455-62
  • Schistosomiasis japonica in the Philippines: the long-term impact of population-based chemotherapy on infection, transmission, and morbidity. J Infect Dis Olveda RM, Daniel BL, Ramirez BDL, Aligui GDL, Acosta LP, Fevidal P, Tiu E, de Veyra F, Peters PA, Romulo R, Domingo E, Wiest PM, Olds GR 1996; 174 (1): 163-72
  • The use of ultrasound mean acoustic attenuation to quantify bone formation during distraction osteogenesis performed by the Ilizarov method. Preliminary results in five dogs. Invest Radiol Daniel BL, Waanders NA, Zhang Y, Moskalik A, Fowlkes JB, Rubin JM, Goulet JA, Adler RS 1994; 29 (10): 933-9
  • Bone scintigraphy in blastomycotic osteomyelitis. Clin Nuc Med Daniel BL, Crabbe JP, Gritters L, Shapiro B. 1993; 18 (3): 203-7
  • Graphic representation of numerically calculated predictive values. an easily comprehended method of evaluating diagnostic tests. Med Decis Making Daniel BL, Daniel TM 1993; 13 (4): 355-8
  • Child growth and schistosomiasis japonica in northeastern Leyte, the Philippines: cross-sectional results. Am J Trop Med Hyg McGarvey ST, Aligui G, Danel BL, Peters P, Olveda RM, Olds GR 1992; 46 (5): 571-81