Dr. Salerno completed his BS in Biological Engineering at Cornell University, and his MD and PhD in Biomedical Engineering at the University of Virginia as part of the Medical Scientist Training Program. He then completed the American Board of Internal Medicine Research Pathway with an Internal Medicine residency at Stanford University, and his general cardiology fellowship at Duke University Medical Center. During his time at Duke he completed a dedicated year in cardiovascular MRI at the Duke Cardiovascular MR Imaging Center. He returned to UVA in 2008 to complete a 2-year advanced cardiovascular imaging fellowship where he trained in CMR and cardiovascular CTA. He achieved COCATS Level III training in all cardiovascular imaging modalities (Echo, Nuclear, CMR, CCT), and is board certified in Echocardiography and Nuclear Cardiology. He served as faculty at UVA in Cardiology, Radiology, and Biomedical Engineering from 2010-2021 where he was the Director of Cardiac MRI and the Medical Director of Echocardiography, before returning to Stanford.
His research involves the development and evaluation of novel MRI pulse sequences and techniques to improve the clinical utility of CMR imaging. The current focus of the research is on quantitative myocardial perfusion imaging, quantitative imaging of myocardial fibrosis, rapid free-breathing and self-gated imaging, and deep learning for image reconstruction and post-processing. His laboratory includes undergraduate and graduate engineering students as well as clinical cardiovascular imaging fellows to bring new advances into clinical practice. Dr. Salerno has been in the field of MRI for 25 years and holds multiple patents related to the development and application of novel pulse sequences for MRI. He has received numerous research awards, and has published extensively in the areas of MRI, cardiovascular MRI and multi-modality cardiovascular imaging. His research has been supported by the AHA and the National Institutes of health. He is a deputy editor for JACC Cardiovascular Imaging.
Outside of work, Dr. Salerno enjoys sailing, rock climbing, skiing, running, biking, hiking, and spending time with his wife Cherie, and his two boys Christopher and Joseph.
- Cardiovascular Disease
Honors & Awards
Fellow, American College of Cardiology (2014)
Best Doctors in America, Best Doctors (2015-2021)
Board Certification, Certification Board of Cardiovascular CT, Cardiovascular CT (2021)
Board Certification: Certification Board of Nuclear Cardiology, Nuclear Cardiology (2010)
Board Certification: National Board of Echocardiography, Adult Comprehensive Echocardiography (2010)
Board Certification: American Board of Internal Medicine, Cardiovascular Disease (2009)
Fellowship, University of Virginia, Advanced Cardiovascular Imaging (2010)
Fellowship: Duke University Cardiovascular Medicine Fellowships (2008) NC
Residency: Stanford University Internal Medicine Residency (2005) CA
Medical Education: University of Virgina School of Medicine (2003) VA
MS, University of Virginia, Statistics (2014)
PhD, University of Virginia, Biomedical Engineering (2003)
MD, University of Virginia, Medicine (2001)
- Society forCardiovascularMagneticResonance perspective on the 2021 AHA/ACC Chest Pain Guidelines. Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance 1800; 24 (1): 8
DEep learning-based rapid Spiral Image REconstruction (DESIRE) for high-resolution spiral first-pass myocardial perfusion imaging.
NMR in biomedicine
The objective of the current study was to develop and evaluate a DEep learning-based rapid Spiral Image REconstruction (DESIRE) technique for high-resolution spiral first-pass myocardial perfusion imaging with whole-heart coverage, to provide fast and accurate image reconstruction for both single-slice (SS) and simultaneous multislice (SMS) acquisitions. Three-dimensional U-Net-based image enhancement architectures were evaluated for high-resolution spiral perfusion imaging at 3T. The SS and SMS MB=2 networks were trained on SS perfusion images from 156 slices from 20 subjects. Structural similarity index (SSIM), peak signal-to-noise ratio (PSNR), and normalized root mean square error (NRMSE) were assessed, and prospective images were blindly graded by two experienced cardiologists (5: excellent; 1: poor). Excellent performance was demonstrated for the proposed technique. For SS, SSIM, PSNR, and NRMSE were 0.977 [0.972, 0.982], 42.113 [40.174, 43.493] dB, and 0.102 [0.080, 0.125], respectively, for the best network. For SMS MB=2 retrospective data, SSIM, PSNR, and NRMSE were 0.961 [0.950, 0.969], 40.834 [39.619, 42.004] dB, and 0.107 [0.086, 0.133], respectively, for the best network. The image quality scores were 4.5 [4.1, 4.8], 4.5 [4.3, 4.6], 3.5 [3.3, 4], and 3.5 [3.3, 3.8] for SS DESIRE, SS L1-SPIRiT, MB=2 DESIRE, and MB=2 SMS-slice-L1-SPIRiT, respectively, showing no statistically significant difference (p=1 and p= 1 for SS and SMS, respectively) between L1-SPIRiT and the proposed DESIRE technique. The network inference time was ~100ms per dynamic perfusion series with DESIRE, while the reconstruction time of L1-SPIRiT with GPU acceleration was ~ 30min. It was concluded that DESIRE enabled fast and high-quality image reconstruction for both SS and SMS MB=2 whole-heart high-resolution spiral perfusion imaging.
View details for DOI 10.1002/nbm.4661
View details for PubMedID 34939246
- Assessing Cardiac Remodeling in AorticRegurgitation Using Indexed Extracellular Volume: More Than Meets the "i"? JACC. Cardiovascular imaging 2021; 14 (11): 2183-2185
Stress Cardiac Magnetic Resonance Myocardial Perfusion Imaging: JACC Review Topic of the Week.
Journal of the American College of Cardiology
2021; 78 (16): 1655-1668
Stress cardiovascular magnetic resonance imaging (CMR) is a cost-effective, noninvasive test that accurately assesses myocardial ischemia, myocardial viability, and cardiac function without the need for ionizing radiation. There is a large body of literature, including randomized controlled trials, validating its diagnostic performance, risk stratification capabilities, and ability to guide appropriate use of coronary intervention. Specifically, stress CMR has shown higher diagnostic sensitivity than single-photon emission computed tomography imaging in detecting angiographically significant coronary artery disease. Stress CMR is particularly valuable for the evaluation of patients with moderate to high pretest probability of having stable ischemic heart disease and for patients known to have challenging imaging characteristics, including women, individuals with prior revascularization, and those with left ventricular dysfunction. This paper reviews the basics principles of stress CMR, the data supporting its clinical use, the added-value of myocardial blood flow quantification, and the assessment of myocardial function and viability routinely obtained during a stress CMR study.
View details for DOI 10.1016/j.jacc.2021.08.022
View details for PubMedID 34649703
- Correction to: Reference ranges ("normal values") for cardiovascular magnetic resonance (CMR) in adults and children: 2020 update. Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance 2021; 23 (1): 114
Toward Replacing Late Gadolinium Enhancement With Artificial Intelligence Virtual Native Enhancement for Gadolinium-Free Cardiovascular Magnetic Resonance Tissue Characterization in Hypertrophic Cardiomyopathy
2021; 144 (8): 589-599
Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging is the gold standard for noninvasive myocardial tissue characterization but requires intravenous contrast agent administration. It is highly desired to develop a contrast agent-free technology to replace LGE for faster and cheaper CMR scans.A CMR virtual native enhancement (VNE) imaging technology was developed using artificial intelligence. The deep learning model for generating VNE uses multiple streams of convolutional neural networks to exploit and enhance the existing signals in native T1 maps (pixel-wise maps of tissue T1 relaxation times) and cine imaging of cardiac structure and function, presenting them as LGE-equivalent images. The VNE generator was trained using generative adversarial networks. This technology was first developed on CMR datasets from the multicenter Hypertrophic Cardiomyopathy Registry, using hypertrophic cardiomyopathy as an exemplar. The datasets were randomized into 2 independent groups for deep learning training and testing. The test data of VNE and LGE were scored and contoured by experienced human operators to assess image quality, visuospatial agreement, and myocardial lesion burden quantification. Image quality was compared using a nonparametric Wilcoxon test. Intra- and interobserver agreement was analyzed using intraclass correlation coefficients (ICC). Lesion quantification by VNE and LGE were compared using linear regression and ICC.A total of 1348 hypertrophic cardiomyopathy patients provided 4093 triplets of matched T1 maps, cines, and LGE datasets. After randomization and data quality control, 2695 datasets were used for VNE method development and 345 were used for independent testing. VNE had significantly better image quality than LGE, as assessed by 4 operators (n=345 datasets; P<0.001 [Wilcoxon test]). VNE revealed lesions characteristic of hypertrophic cardiomyopathy in high visuospatial agreement with LGE. In 121 patients (n=326 datasets), VNE correlated with LGE in detecting and quantifying both hyperintensity myocardial lesions (r=0.77-0.79; ICC=0.77-0.87; P<0.001) and intermediate-intensity lesions (r=0.70-0.76; ICC=0.82-0.85; P<0.001). The native CMR images (cine plus T1 map) required for VNE can be acquired within 15 minutes and producing a VNE image takes less than 1 second.VNE is a new CMR technology that resembles conventional LGE but without the need for contrast administration. VNE achieved high agreement with LGE in the distribution and quantification of lesions, with significantly better image quality.
View details for DOI 10.1161/CIRCULATIONAHA.121.054432
View details for Web of Science ID 000687804500008
View details for PubMedID 34229451
View details for PubMedCentralID PMC8378544
Cardiac Magnetic Resonance Assessment of Response to Cardiac Resynchronization Therapy and Programming Strategies.
JACC. Cardiovascular imaging
OBJECTIVES: The objective was to determine the feasibility and effectiveness of cardiac magnetic resonance (CMR) cine and strain imaging before and after cardiac resynchronization therapy (CRT) for assessment of response and the optimal resynchronization pacing strategy.BACKGROUND: CMR with cardiac implantable electronic devices can safely provide high-quality right ventricular/left ventricular (LV) ejection fraction (RVEF/LVEF) assessments and strain.METHODS: CMR with cine imaging, displacement encoding with stimulated echoes for the circumferential uniformity ratio estimate with singular value decomposition (CURE-SVD) dyssynchrony parameter, and scar assessment was performed before and after CRT. Whereas the pre-CRT scan constituted a single "imaging set" with complete volumetric, strain, and scar imaging, multiple imaging sets with complete strain and volumetric data were obtained during the post-CRT scan for biventricular pacing (BIVP), LV pacing (LVP), and asynchronous atrial pacing modes by reprogramming the device outside the scanner between imaging sets.RESULTS: 100 CMRs with a total of 162 imaging sets were performed in 50 patients (median age 70 years [IQR: 50 years-86 years]; 48% female). Reduction in LV end-diastolic volumes (P = 0.002) independent of CRT pacing were more prominent than corresponding reductions in right ventricular end-diastolic volumes (P = 0.16). A clear dependence of the optimal CRT pacing mode (BIVP vs LVP) on the PR interval (P = 0.0006) was demonstrated. The LVEF and RVEF improved more with BIVP than LVP with PR intervals≥240 milliseconds (P = 0.025 and P = 0.002, respectively); the optimal mode (BIVP vs LVP) was variable with PR intervals<240 milliseconds. A lower pre-CRT displacement encoding with stimulated echoes CURE-SVD was associated with greater improvements in the post-CRT CURE-SVD (r =-0.69; P<0.001), LV end-systolic volume (r =-0.58; P< 0.001), and LVEF (r =-0.52; P< 0.001).CONCLUSIONS: CMR evaluation with assessment of multiple pacing modes during a single scan after CRT is feasible and provides useful information for patient care with respect to response and the optimal pacing strategy.
View details for DOI 10.1016/j.jcmg.2021.06.015
View details for PubMedID 34419391
Venoarterial Extracorporeal Membrane Oxygenation for Acute Massive Pulmonary Embolism: a Meta-Analysis and Call to Action
JOURNAL OF CARDIOVASCULAR TRANSLATIONAL RESEARCH
Venoarterial extracorporeal membrane oxygenation (ECMO) has been used to treat acute massive pulmonary embolism (PE) patients. However, the incremental benefit of ECMO to standard therapy remains unclear. Our meta-analysis objective is to compare in-hospital mortality in patients treated for acute massive PE with and without ECMO. The National Library of Medicine MEDLINE (USA), Web of Science, and PubMed databases from inception through October 2020 were searched. Screening identified 1002 published articles. Eleven eligible studies were identified, and 791 patients with acute massive PE were included, of whom 270 received ECMO and 521 did not. In-hospital mortality was not significantly different between patients treated with vs. without ECMO (OR = 1.24 [95% CI, 0.63-2.44], p = 0.54). However, these findings were limited by significant study heterogeneity. Additional research will be needed to clarify the role of ECMO in massive PE treatment. In-hospital mortality for patients with acute massive pulmonary embolism was not significantly different (OR of 1.24, p = 0.54) between those treated with and without venoarterial ECMO.
View details for DOI 10.1007/s12265-021-10158-0
View details for Web of Science ID 000674534900001
View details for PubMedID 34282541
View details for PubMedCentralID PMC8288068
Functional and Economic Impact of INOCA and Influence of Coronary Microvascular Dysfunction
2021; 14 (7): 1369-1379
This study sought to better characterize the quality of life and economic impact in patients with symptoms of ischemia and no obstructive coronary disease (INOCA) and to identify the influence of coronary microvascular dysfunction (CMD).Patients with INOCA have a high symptom burden and an increased incidence of major adverse cardiac events. CMD is a frequent cause of INOCA. The morbidity associated with INOCA and CMD has not been well-characterized.Sixty-six patients with INOCA underwent stress cardiac magnetic resonance with calculation of myocardial perfusion reserve (MPR); MPR 2.0 to 2.4 was considered borderline-reduced (possible CMD) and MPR <2.0 was defined as reduced (definite CMD). Subjects completed quality of life questionnaires to assess the morbidity and economic impact of INOCA. Questionnaire results were compared between INOCA patients with and without CMD. In addition, logistic regression was used to determine the predictors of CMD within the INOCA population.The prevalence of definite CMD was 24%. Definite or borderline CMD was present in 59% (MPR ≤2.4). Patients with INOCA reported greater physical limitation, angina frequency, and reduced quality of life compared to referent stable coronary artery disease and acute myocardial infarction populations. In addition, Patients with INOCA reported frequent time missed from work and work limitations, suggesting a substantial economic impact. No difference was observed in reported symptoms between INOCA patients with and without CMD. Glomerular filtration rate and body-mass index were significant predictors of CMD in multivariable regression analysis.INOCA is associated with high morbidity similar to other high-risk cardiac populations, and work limitations reported by Patients with INOCA suggest a substantial economic impact. CMD is a common cause of INOCA but is not associated with increased morbidity. These results suggest that there is significant symptom burden in the INOCA population regardless of etiology.
View details for DOI 10.1016/j.jcmg.2021.01.041
View details for Web of Science ID 000697114900011
View details for PubMedID 33865784
View details for PubMedCentralID PMC8273074
- Dual excitation flip angle simultaneous cine and T-1 mapping using SPiral Acquisition with Respiratory and Cardiac Self-gating (CAT-SPARCS) (vol 86, pg 82, 2021) MAGNETIC RESONANCE IN MEDICINE 2021
Predictors of Major Atrial Fibrillation Endpoints in the National Heart, Lung, and Blood Institute HCMR.
JACC. Clinical electrophysiology
OBJECTIVES: This study sought to identify predictors of major clinically important atrial fibrillation endpoints in hypertrophic cardiomyopathy.BACKGROUND: Atrial fibrillation (AF) is a common morbidity associated with hypertrophic cardiomyopathy (HCM). The HCMR (Hypertrophic Cardiomyopathy Registry) trial is a prospective natural history study of 2,755 patients with HCM with comprehensive phenotyping.METHODS: All patients received yearly telephone follow-up. Major AF endpoints were defined as requiring electrical cardioversion, catheter ablation, hospitalization for >24 h, or clinical decisions to accept permanent AF. Penalized regression via elastic-net methodology identified the most important predictors of major AF endpoints from 46 variables. This was applied to 10 datasets, and the variables were ranked. Predictors that appeared in all 10 sets were then used in a Cox model for competing risks and analyzed as time to first event.RESULTS: Data from 2,631 (95.5%) patients were available for analysis after exclusions. A total of 127 major AF endpoints events occurred in 96 patients over 33.3 ± 12.4months. In the final model, age, body mass index (BMI), left atrial (LA) volume index, LA contractile percent (active contraction), moderate or severe mitral regurgitation (MR), and history of arrhythmia the most important. BMI, LA volume index, and LA contractile percent were age-dependent. Obesity was a stronger risk factor in younger patients. Increased LA volume, reduced LA contractile percent, and moderate or severe MR put middle-aged and older adult patients at increased risk.CONCLUSIONS: The major predictors of major AF endpoints in HCM include older age, high BMI, moderate or severe MR, history of arrhythmia, increased LA volume, and reduced LA contractile percent. Prospective testing of a risk score based on these parameters may be warranted.
View details for DOI 10.1016/j.jacep.2021.04.004
View details for PubMedID 34217663
AN UNUSUAL STEMI: CMR DEMONSTRATES ARRHYTHMOGENIC RV CARDIOMYOPATHY (ARVC) AS LIKELY CAUSE FOR VENTRICULAR FIBRILLATION
ELSEVIER SCIENCE INC. 2021: 2668
View details for Web of Science ID 000647487502682
Quality assurance of quantitative cardiac T1-mapping in multicenter clinical trials - A T1 phantom program from the hypertrophic cardiomyopathy registry (HCMR) study
INTERNATIONAL JOURNAL OF CARDIOLOGY
2021; 330: 251-258
Quantitative cardiovascular magnetic resonance T1-mapping is increasingly used for myocardial tissue characterization. However, the lack of standardization limits direct comparability between centers and wider roll-out for clinical use or trials.To develop a quality assurance (QA) program assuring standardized T1 measurements for clinical use.MR phantoms manufactured in 2013 were distributed, including ShMOLLI T1-mapping and reference T1 and T2 protocols. We first studied the T1 and T2 dependency on temperature and phantom aging using phantom datasets from a single site over 4 years. Based on this, we developed a multiparametric QA model, which was then applied to 78 scans from 28 other multi-national sites.T1 temperature sensitivity followed a second-order polynomial to baseline T1 values (R2 > 0.996). Some phantoms showed aging effects, where T1 drifted up to 49% over 40 months. The correlation model based on reference T1 and T2, developed on 1004 dedicated phantom scans, predicted ShMOLLI-T1 with high consistency (coefficient of variation 1.54%), and was robust to temperature variations and phantom aging. Using the 95% confidence interval of the correlation model residuals as the tolerance range, we analyzed 390 ShMOLLI T1-maps and confirmed accurate sequence deployment in 90%(70/78) of QA scans across 28 multiple centers, and categorized the rest with specific remedial actions.The proposed phantom QA for T1-mapping can assure correct method implementation and protocol adherence, and is robust to temperature variation and phantom aging. This QA program circumvents the need of frequent phantom replacements, and can be readily deployed in multicenter trials.
View details for DOI 10.1016/j.ijcard.2021.01.026
View details for Web of Science ID 000637586400047
View details for PubMedID 33535074
View details for PubMedCentralID PMC7994017
Diagnostic Accuracy of Spiral Whole-Heart Quantitative Adenosine Stress Cardiovascular Magnetic Resonance With Motion Compensated L1-SPIRIT
JOURNAL OF MAGNETIC RESONANCE IMAGING
2021; 54 (4): 1268-1279
Variable density spiral (VDS) pulse sequences with motion compensated compressed sensing (MCCS) reconstruction allow for whole-heart quantitative assessment of myocardial perfusion but are not clinically validated.Assess performance of whole-heart VDS quantitative stress perfusion with MCCS to detect obstructive coronary artery disease (CAD).Prospective cross sectional.Twenty-five patients with chest pain and known or suspected CAD and nine normal subjects.Segmented steady-state free precession (SSFP) sequence, segmented phase sensitive inversion recovery sequence for late gadolinium enhancement (LGE) imaging and VDS sequence at 1.5 T for rest and stress quantitative perfusion at eight short-axis locations.Stenosis was defined as ≥50% by quantitative coronary angiography (QCA). Visual and quantitative analysis of MRI data was compared to QCA. Quantitative analysis assessed average myocardial perfusion reserve (MPR), average stress myocardial blood flow (MBF), and lowest stress MBF of two contiguous myocardial segments. Ischemic burden was measured visually and quantitatively.Student's t-test, McNemar's test, chi-square statistic, linear mixed-effects model, and area under receiver-operating characteristic curve (ROC).Per-patient visual analysis demonstrated a sensitivity of 84% (95% confidence interval [CI], 60%-97%) and specificity of 83% [95% CI, 36%-100%]. There was no significant difference between per-vessel visual and quantitative analysis for sensitivity (69% [95% CI, 51%-84%] vs. 77% [95% CI, 60%-90%], P = 0.39) and specificity (88% [95% CI, 73%-96%] vs. 80% [95% CI, 64%-91%], P = 0.75). Per-vessel quantitative analysis ROC showed no significant difference (P = 0.06) between average MPR (0.68 [95% CI, 0.56-0.81]), average stress MBF (0.74 [95% CI, 0.63-0.86]), and lowest stress MBF (0.79 [95% CI, 0.69-0.90]). Visual and quantitative ischemic burden measurements were comparable (P = 0.85).Whole-heart VDS stress perfusion demonstrated good diagnostic accuracy and ischemic burden evaluation. No significant difference was seen between visual and quantitative diagnostic performance and ischemic burden measurements.2 TECHNICAL EFFICACY: Stage 2.
View details for DOI 10.1002/jmri.27620
View details for Web of Science ID 000637047300001
View details for PubMedID 33822426
High spatial resolution spiral first-pass myocardial perfusion imaging with whole-heart coverage at 3 T
MAGNETIC RESONANCE IN MEDICINE
To develop and evaluate a high spatial resolution (1.25 × 1.25 mm2 ) spiral first-pass myocardial perfusion imaging technique with whole-heart coverage at 3T, to better assess transmural differences in perfusion between the endocardium and epicardium, to quantify the myocardial ischemic burden, and to improve the detection of obstructive coronary artery disease.Whole-heart high-resolution spiral perfusion pulse sequences and corresponding motion-compensated reconstruction techniques for both interleaved single-slice (SS) and simultaneous multi-slice (SMS) acquisition with or without outer-volume suppression (OVS) were developed. The proposed techniques were evaluated in 34 healthy volunteers and 8 patients (55 data sets). SS and SMS images were reconstructed using motion-compensated L1-SPIRiT and SMS-Slice-L1-SPIRiT, respectively. Images were blindly graded by 2 experienced cardiologists on a 5-point scale (5, excellent; 1, poor).High-quality perfusion imaging was achieved for both SS and SMS acquisitions with or without OVS. The SS technique without OVS had the highest scores (4.5 [4, 5]), which were greater than scores for SS with OVS (3.5 [3.25, 3.75], P < .05), MB = 2 without OVS (3.75 [3.25, 4], P < .05), and MB = 2 with OVS (3.75 [2.75, 4], P < .05), but significantly higher than those for MB = 3 without OVS (4 [4, 4], P = .95). SMS image quality was improved using SMS-Slice-L1-SPIRiT as compared to SMS-L1-SPIRiT (P < .05 for both reviewers).We demonstrated the successful implementation of whole-heart spiral perfusion imaging with high resolution at 3T. Good image quality was achieved, and the SS without OVS showed the best image quality. Evaluation in patients with expected ischemic heart disease is warranted.
View details for DOI 10.1002/mrm.28701
View details for Web of Science ID 000627605000001
View details for PubMedID 33709415
Valve-sparing aortic root replacement after neonatal arterial switch operation
JOURNAL OF CARDIAC SURGERY
2021; 36 (6): 2146-2148
Arterial switch operations (ASO) are lifesaving procedures performed on neonates to treat transposition of the great arteries. However, future operations on the neoaorta may be required due to dilation. We present a case of a 25-year-old female who presented with dilation of her neoaorta and required a David procedure. Her previous ASO resulted in an anterior lie of the pulmonary artery in front of the neoaorta, with both coronary arteries coming off anteriorly. We describe our approach to performing a David procedure on this patient with this unique anatomy.
View details for DOI 10.1111/jocs.15466
View details for Web of Science ID 000622333100001
View details for PubMedID 33638201
View details for PubMedCentralID PMC8107120
Dual-excitation flip-angle simultaneous cine and T-1 mapping using spiral acquisition with respiratory and cardiac self-gating
MAGNETIC RESONANCE IN MEDICINE
To develop a free-breathing cardiac self-gated technique that provides cine images and B 1 + slice profile-corrected T1 maps from a single acquisition.Without breath-holding or electrocardiogram gating, data were acquired continuously on a 3T scanner using a golden-angle gradient-echo spiral pulse sequence, with an inversion RF pulse applied every 4 seconds. Flip angles of 3° and 15° were used for readouts after the first four and second four inversions. Self-gating cardiac triggers were extracted from heart image navigators, and respiratory motion was corrected by rigid registration on each heartbeat. Cine images were reconstructed from the steady-state portion of 15° readouts using a low-rank plus sparse reconstruction. The T1 maps were fit using a projection onto convex sets approach from images reconstructed using slice profile-corrected dictionary learning. This strategy was evaluated in a phantom and 14 human subjects.The self-gated signal demonstrated close agreement with the acquired electrocardiogram signal. The image quality for the proposed cine images and standard clinical balanced SSFP images were 4.31 (±0.50) and 4.65 (±0.30), respectively. The slice profile-corrected T1 values were similar to those of the inversion-recovery spin-echo technique in phantom, and had a higher global T1 value than that of MOLLI in human subjects.Cine and T1 mapping using spiral acquisition with respiratory and cardiac self-gating successfully acquired T1 maps and cine images in a single acquisition without the need for electrocardiogram gating or breath-holding. This dual-excitation flip-angle approach provides a novel approach for measuring T1 while accounting for B 1 + and slice profile effect on the apparent T 1 ∗ .
View details for DOI 10.1002/mrm.28675
View details for Web of Science ID 000618101100001
View details for PubMedID 33590591
Common genetic variants and modifiable risk factors underpin hypertrophic cardiomyopathy susceptibility and expressivity
2021; 53 (2): 135-+
Hypertrophic cardiomyopathy (HCM) is a common, serious, genetic heart disorder. Rare pathogenic variants in sarcomere genes cause HCM, but with unexplained phenotypic heterogeneity. Moreover, most patients do not carry such variants. We report a genome-wide association study of 2,780 cases and 47,486 controls that identified 12 genome-wide-significant susceptibility loci for HCM. Single-nucleotide polymorphism heritability indicated a strong polygenic influence, especially for sarcomere-negative HCM (64% of cases; h2g = 0.34 ± 0.02). A genetic risk score showed substantial influence on the odds of HCM in a validation study, halving the odds in the lowest quintile and doubling them in the highest quintile, and also influenced phenotypic severity in sarcomere variant carriers. Mendelian randomization identified diastolic blood pressure (DBP) as a key modifiable risk factor for sarcomere-negative HCM, with a one standard deviation increase in DBP increasing the HCM risk fourfold. Common variants and modifiable risk factors have important roles in HCM that we suggest will be clinically actionable.
View details for DOI 10.1038/s41588-020-00764-0
View details for Web of Science ID 000611467100003
View details for PubMedID 33495597
View details for PubMedCentralID PMC8240954
Meta-Analysis of New-Onset Atrial Fibrillation Versus No History of Atrial Fibrillation in Patients With Noncardiac Critical Care Illness.
The American journal of cardiology
The incidence of new-onset secondary atrial fibrillation (NOSAF) is as high as 44% in noncardiac critical illness. A systematic review and meta-analysis were performed to evaluate the impact of NOSAF, compared with history of prior atrial fibrillation (AF) and no history of AF in noncardiac critically ill patients. Patients undergoing cardiothoracic surgery were excluded. NOSAF incidence, intensive care unit (ICU)/hospital length of stay (LOS), and mortality outcomes were analyzed. Of 2,360 studies reviewed, 19 studies met inclusion criteria (n = 306,805 patients). NOSAF compared with no history of AF was associated with increased in-hospital mortality (risk ratio [RR] 2.06, 95% confidence interval [CI] 1.76 to 2.41, p <0.001), longer ICU LOS (standardized difference in means [SMD] 0.66, 95% CI 0.41 to 0.91, p <0.001), longer hospital LOS (SMD 0.31, 95% CI 0.07 to 0.56, p = 0.001) and increased risk of long-term (>1 year) mortality (RR 1.76, 95% CI 1.29 to 2.40, p <0.001). NOSAF compared with previous AF was also associated with higher in-hospital mortality (RR 1.29, 95% CI 1.12 to 1.49, p <0.001), longer ICU LOS (SMD 0.37, 95% CI 0.03 to 0.70, p = 0.03) but no difference in-hospital LOS (SMD -0.18, 95% CI -0.66 to 0.31, p = 0.47). In conclusion, NOSAF, in the setting of noncardiac critical illness is associated with increased in-hospital mortality compared with no history of AF and previous AF. NOSAF (vs no history of AF) is also associated with increased long-term mortality.
View details for DOI 10.1016/j.amjcard.2021.10.036
View details for PubMedID 34815061
Cost-effectiveness Analysis of Anatomic vs Functional Index Testing in Patients With Low-Risk Stable Chest Pain
JAMA NETWORK OPEN
2020; 3 (12): e2028312
Both noninvasive anatomic and functional testing strategies are now routinely used as initial workup in patients with low-risk stable chest pain (SCP).To determine whether anatomic approaches (ie, coronary computed tomography angiography [CTA] and coronary CTA supplemented with noninvasive fractional flow reserve [FFRCT], performed in patients with 30% to 69% stenosis) are cost-effective compared with functional testing for the assessment of low-risk SCP.This cost-effectiveness analysis used an individual-based Markov microsimulation model for low-risk SCP. The model was developed using patient data from the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial. The model was validated by comparing model outcomes with outcomes observed in the PROMISE trial for anatomic (coronary CTA) and functional (stress testing) strategies, including diagnostic test results, referral to invasive coronary angiography (ICA), coronary revascularization, incident major adverse cardiovascular event (MACE), and costs during 60 days and 2 years. The validated model was used to determine whether anatomic approaches are cost-effective over a lifetime compared with functional testing.Choice of index test for evaluation of low-risk SCP.Downstream ICA and coronary revascularization, MACE (death, nonfatal myocardial infarction), cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) of competing strategies.The model cohort included 10 003 individual patients (median [interquartile range] age, 60.0 [54.4-65.9] years; 5270 [52.7%] women; 7693 [77.4%] White individuals), who entered the model 100 times. The Markov model accurately estimated the test assignment, results of anatomic and functional index testing, referral to ICA, revascularization, MACE, and costs at 60 days and 2 years compared with observed data in PROMISE (eg, coronary CTA: ICA, 12.2% [95% CI, 10.9%-13.5%] vs 12.3% [95% CI, 12.2%-12.4%]; revascularization, 6.2% [95% CI, 5.5%-6.9%] vs 6.4% [95% CI, 6.3%-6.5%]; functional strategy: ICA, 8.1% [95% CI, 7.4%-8.9%] vs 8.2% [95% CI, 8.1%-8.3%]; revascularization, 3.2% [95% CI, 2.7%-3.7%] vs 3.3% [95% CI, 3.2%-3.4%]; 2-year MACE rates: coronary CTA, 2.1% [95% CI, 1.7%-2.5%] vs 2.3% [95% CI, 2.2%-2.4%]; functional strategy, 2.2% [95% CI, 1.8%-2.6%] vs 2.4% [95% CI, 2.3%-2.4%]). Anatomic approaches led to higher ICA and revascularization rates at 60 days, 2 years, and 5 years compared with functional testing but were more effective in patient selection for ICA (eg, 60-day revascularization-to-ICA ratio, CTA: 53.7% [95% CI, 53.3%-54.0%]; CTA with FFRCT: 59.5% [95% CI, 59.2%-59.8%]; functional testing: 40.7% [95% CI, 40.4%-50.0%]). Over a lifetime, anatomic approaches gained an additional 6 months in perfect health compared with functional testing (CTA, 25.16 [95% CI, 25.14-25.19] QALYs; CTA with FFRCT, 25.14 [95% CI, 25.12-25.17] QALYs; functional testing, 24.68 [95% CI, 24.66-24.70] QALYs). Anatomic strategies were less costly and more effective; thus, CTA with FFRCT dominated and CTA alone was cost-effective (ICERs ranged from $1912/QALY for women and $3,559/QALY for men) compared with functional testing. In probabilistic sensitivity analyses, anatomic approaches were cost-effective in more than 65% of scenarios, assuming a willingness-to-pay threshold of $100 000/QALY.The results of this study suggest that anatomic strategies may present a more favorable initial diagnostic option in the evaluation of low-risk SCP compared with functional testing.
View details for DOI 10.1001/jamanetworkopen.2020.28312
View details for Web of Science ID 000600982200001
View details for PubMedID 33315111
View details for PubMedCentralID PMC7737090
Reference ranges ("normal values") for cardiovascular magnetic resonance (CMR) in adults and children: 2020 update
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2020; 22 (1): 87
Cardiovascular magnetic resonance (CMR) enables assessment and quantification of morphological and functional parameters of the heart, including chamber size and function, diameters of the aorta and pulmonary arteries, flow and myocardial relaxation times. Knowledge of reference ranges ("normal values") for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. Compared to the previous version of this review published in 2015, we present updated and expanded reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques. Further, databases and references for deep learning methods are included.
View details for DOI 10.1186/s12968-020-00683-3
View details for Web of Science ID 000599865800002
View details for PubMedID 33308262
View details for PubMedCentralID PMC7734766
Free-Breathing and Ungated Dynamic MRI Using Navigator-Less Spiral SToRM
IEEE TRANSACTIONS ON MEDICAL IMAGING
2020; 39 (12): 3933-3943
We introduce a kernel low-rank algorithm to recover free-breathing and ungated dynamic MRI from spiral acquisitions without explicit k-space navigators. It is often challenging for low-rank methods to recover free-breathing and ungated images from undersampled measurements; extensive cardiac and respiratory motion often results in the Casorati matrix not being sufficiently low-rank. Therefore, we exploit the non-linear structure of the dynamic data, which gives the low-rank kernel matrix. Unlike prior work that rely on navigators to estimate the manifold structure, we propose a kernel low-rank matrix completion method to directly fill in the missing k-space data from variable density spiral acquisitions. We validate the proposed scheme using simulated data and in-vivo data. Our results show that the proposed scheme provides improved reconstructions compared to the classical methods such as low-rank and XD-GRASP. The comparison with breath-held cine data shows that the quantitative metrics agree, whereas the image quality is marginally lower.
View details for DOI 10.1109/TMI.2020.3008329
View details for Web of Science ID 000595547500016
View details for PubMedID 32746136
View details for PubMedCentralID PMC7806246
- CMR in the Era of COVID-19 Evaluation of Myocarditis in the Subacute Phase JACC-CARDIOVASCULAR IMAGING 2020; 13 (11): 2340-2342
Coronary Computed Tomography Angiography Demonstrates a High Burden of Coronary Artery Disease Despite Low-Risk Nuclear Studies in Pre-Liver Transplant Evaluation
2020; 26 (11): 1398-1408
We investigated the presence and severity of coronary artery disease (CAD) in orthotopic liver transplantation (OLT) candidates using coronary artery calcium score (CACS) and coronary computed tomography angiography (CCTA) as compared with the prevalence of normal and abnormal single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). A total of 140 prospective OLT candidates without known CAD underwent coronary artery calcium (CAC) scans with (n = 77) or without CCTA and coronary computed tomography angiography-derived fractional flow reserve (FFRCT ; n = 57) using a dual-source computed tomography (CT) and were followed for 2.6 ± 1.4 years. Coronary plaque was quantified using the segment-involvement score (SIS) and segment stenosis score (SSS). The mean age was 59 ± 6 years, and 65.0% of patients were male. Mean Agatston CACS was 367 ± 653, and 15.0% of patients had CACSs of 0; 83.6% received a SPECT MPI, of which 95.7% were interpreted as normal/probably normal. By CCTA, 9.1% had obstructive CAD (≥70% stenosis), 67.5% had nonobstructive CAD, and 23.4% had no CAD. Nonobstructive CAD was diffuse with mean SIS 3.0 ± 2.9 and SSS 4.5 ± 5.4. Only 14 patients had high risk-findings (severe 3v CAD, n = 4, CACS >1000 n = 10) that prompted X-ray angiography in 3 patients who had undergone CCTA, resulting in revascularization of a high-risk obstruction in 1 patient who had a normal SPECT study. Patients with end-stage liver disease have a high prevalence of nonobstructive CAD by CCTA, which is undiagnosed by SPECT MPI, potentially underestimating cardiovascular risk. Deferring X-ray angiography unless high-risk CCTA findings are present is a potential strategy for avoiding unnecessary X-ray angiography.
View details for DOI 10.1002/lt.25869
View details for Web of Science ID 000581705900005
View details for PubMedID 32772465
T2 Relaxation Times at Cardiac MRI in Healthy Adults: A Systematic Review and Meta-Analysis
2020; 297 (2): 344-351
Background T2 mapping is an important cardiac MRI technique with applications in various conditions. However, a comprehensive evaluation of the T2 literature for normal values is lacking. Purpose To characterize the ranges of normal values and variability of myocardial T2 relaxation times using a systematic review and meta-analysis of the T2 literature. Materials and Methods PubMed and Cochrane Central were searched from June 2019 to January 2020 for myocardial T2 measurements in healthy adults. Studies quantifying T2 relaxation times conducted at 1.5 T or 3.0 T using gradient and spin-echo (GRASE) or T2-prepared balanced steady-state free precession sequences were included. Summary means were generated using a random-effects model. Subgroup analysis and meta-regression were performed to assess factors causing heterogeneity. Results Of the 2481 articles retrieved, 42 studies were included with 954 healthy adults (mean age, 42.4 years ± 10.5 [standard deviation]; 538 men). The pooled mean of T2 across studies was 52 msec at 1.5 T (95% confidence interval [CI]: 51 msec, 53 msec) and 46 msec at 3.0 T (95% CI: 44 msec, 48 msec) (P ≤ .001). I2 was 98% at 1.5 T and 3.0 T. Meta-regression at 1.5 T and 3.0 T identified vendor (β at 1.5 T = -4 msec [with Philips as reference], P < .001; β at 3.0 T = -5 msec, P = .02) and pulse sequence (β at 1.5 T = -5 msec [with GRASE as reference], P < .001; β at 3.0 T = -6 msec, P = .002) as significant covariates, but it did not identify any association with covariates of age (β at 1.5 T = 0 msec per year, P = .70; β at 3.0 T = 0 msec per year, P = .83) or sex (β at 1.5 T = -1 msec, P = .88; β at 3.0 T = 6 msec, P = .42). Conclusion The pooled mean of T2 relaxation times in healthy adults had marked heterogeneity across studies with field strength, vendor, and pulse sequence identified as covariates associated with T2. T2-prepared measurements were similar between vendors at each field strength. © RSNA, 2020 Online supplemental material is available for this article.
View details for DOI 10.1148/radiol.2020200989
View details for Web of Science ID 000581882100025
View details for PubMedID 32840469
View details for PubMedCentralID PMC7605362
Society for Cardiovascular Magnetic Resonance (SCMR) guidance for re-activation of cardiovascular magnetic resonance practice after peak phase of the COVID-19 pandemic
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2020; 22 (1): 58
During the peak phase of the COVID-19 pandemic, alterations of standard operating procedures were necessary for health systems to protect patients and healthcare workers and ensure access to vital hospital resources. As the peak phase passes, re-activation plans are required to safely manage increasing clinical volumes. In the context of cardiovascular magnetic resonance (CMR), re-activation objectives include continued performance of urgent CMR studies and resumption of CMR in patients with semi-urgent and elective indications in an environment that is safe for both patients and health care workers.
View details for DOI 10.1186/s12968-020-00654-8
View details for Web of Science ID 000561205500001
View details for PubMedID 32772930
View details for PubMedCentralID PMC7415346
New-onsetatrial fibrillation and outcomes following isolated coronary artery bypass surgery: A systematic review andmeta-analysis
2020; 43 (9): 928-934
Prior meta-analyses have shown that new-onset atrial fibrillation (NOAF) occurs in up to 40% of patients following cardiac surgery and is associated with substantial major adverse cardiovascular events. The stroke and mortality implications of NOAF in isolated CABG without concomitant valve surgery is not known. We thought that NOAF would be associated with increased risk of stroke and mortality, even in patients undergoing isolated CABG. A blinded review of studies from MEDLINE, CENTRAL, and Web of Science was done by two independent investigators. Stroke, 30-day/hospital mortality, long-term cardiovascular mortality, and long-term (>1 year) all-cause mortality were analyzed. We used Review Manager Version 5.3 to perform pooled analysis of outcomes. Of 4461 studies identified, 19 studies (n = 129 628) met inclusion criteria. NOAF incidence ranged from 15% to 36%. NOAF was associated with increased risk of stroke (unadjusted OR 2.15 [1.82, 2.53] [P < .00001]; adjusted OR 1.88 [1.02, 3.46] [P = .04]). NOAF was associated with increased 30-day/hospital mortality (OR 2.35 [1.67, 3.32] [P < .00001]) and long-term cardiovascular mortality (OR 2.04 [1.35, 3.09] [P = .0007]) NOAF was associated with increased long-term all-cause mortality (unadjusted OR 1.79 [1.63, 1.96] [P < .00001]; adjusted OR 1.58 [1.24, 2.00] [P = .0002]). We found that the incidence of NOAF following isolated CABG is high and is associated with increased stroke rate and mortality. Early recognition and management of NOAF could improve outcomes.
View details for DOI 10.1002/clc.23414
View details for Web of Science ID 000550656200001
View details for PubMedID 32696468
View details for PubMedCentralID PMC7462196
Cardiovascular Imaging Techniques to Assess Microvascular Dysfunction 0 EBAC'
2020; 13 (7): 1577-1590
The understanding of microvascular dysfunction without evidence of epicardial coronary artery disease pales in comparison with that of obstructive epicardial coronary artery disease. A primary limitation in the past had been the lack of development of noninvasive methods of detecting and quantifying microvascular dysfunction. This limitation has particularly affected the ability to study the pathophysiology, morbidity, and treatment of this disease. More recently, almost all of the noninvasive cardiac imaging modalities have been used to quantify blood flow and advance understanding of microvascular dysfunction.
View details for DOI 10.1016/j.jcmg.2019.09.006
View details for Web of Science ID 000547577300001
View details for PubMedID 31607665
View details for PubMedCentralID PMC7148179
Reevaluation of the South AsianMYBPC3(Delta 25bp)Intronic Deletion in Hypertrophic Cardiomyopathy
CIRCULATION-GENOMIC AND PRECISION MEDICINE
2020; 13 (3): 101-109
The common intronic deletion, MYBPC3Δ25, detected in 4% to 8% of South Asian populations, is reported to be associated with cardiomyopathy, with ≈7-fold increased risk of disease in variant carriers. Here, we examine the contribution of MYBPC3Δ25 to hypertrophic cardiomyopathy (HCM) in a large patient cohort.Sequence data from 2 HCM cohorts (n=5393) was analyzed to determine MYBPC3Δ25 frequency and co-occurrence of pathogenic variants in HCM genes. Case-control and haplotype analyses were performed to compare variant frequencies and assess disease association. Analyses were also undertaken to investigate the pathogenicity of a candidate variant MYBPC3 c.1224-52G>A.Our data suggest that the risk of HCM, previously attributed to MYBPC3Δ25, can be explained by enrichment of a derived haplotype, MYBPC3Δ25/-52, whereby a small subset of individuals bear both MYBPC3Δ25 and a rare pathogenic variant, MYBPC3 c.1224-52G>A. The intronic MYBPC3 c.1224-52G>A variant, which is not routinely evaluated by gene panel or exome sequencing, was detected in ≈1% of our HCM cohort.The MYBPC3 c.1224-52G>A variant explains the disease risk previously associated with MYBPC3Δ25 in the South Asian population and is one of the most frequent pathogenic variants in HCM in all populations; genotyping services should ensure coverage of this deep intronic mutation. Individuals carrying MYBPC3Δ25 alone are not at increased risk of HCM, and this variant should not be tested in isolation; this is important for the large majority of the 100 million individuals of South Asian ancestry who carry MYBPC3Δ25 and would previously have been declared at increased risk of HCM.
View details for DOI 10.1161/CIRCGEN.119.002783
View details for Web of Science ID 000545932800006
View details for PubMedID 32163302
View details for PubMedCentralID PMC7299222
Off-label Use of Direct Oral Anticoagulants Compared With Warfarin for Left Ventricular Thrombi
2020; 5 (6): 685-692
Left ventricular (LV) thrombi can arise in patients with ischemic and nonischemic cardiomyopathies. Anticoagulation is thought to reduce the risk of stroke or systemic embolism (SSE), but there are no high-quality data on the effectiveness of direct oral anticoagulants (DOACs) for this indication.To compare the outcomes associated with DOAC use and warfarin use for the treatment of LV thrombi.A cohort study was performed at 3 tertiary care academic medical centers among 514 eligible patients with echocardiographically diagnosed LV thrombi between October 1, 2013, and March 31, 2019. Follow-up was performed through the end of the study period.Type and duration of anticoagulant use.Clinically apparent SSE.A total of 514 patients (379 men; mean [SD] age, 58.4 [14.8] years) with LV thrombi were identified, including 300 who received warfarin and 185 who received a DOAC (64 patients switched treatment between these groups). The median follow-up across the patient cohort was 351 days (interquartile range, 51-866 days). On unadjusted analysis, DOAC treatment vs warfarin use (hazard ratio [HR], 2.71; 95% CI, 1.31-5.57; P = .01) and prior SSE (HR, 2.13; 95% CI, 1.22-3.72; P = .01) were associated with SSE. On multivariable analysis, anticoagulation with DOAC vs warfarin (HR, 2.64; 95% CI, 1.28-5.43; P = .01) and prior SSE (HR, 2.07; 95% CI, 1.17-3.66; P = .01) remained significantly associated with SSE.In this multicenter cohort study of anticoagulation strategies for LV thrombi, DOAC treatment was associated with a higher risk of SSE compared with warfarin use, even after adjustment for other factors. These results challenge the assumption of DOAC equivalence with warfarin for LV thrombi and highlight the need for prospective randomized clinical trials to determine the most effective treatment strategies for LV thrombi.
View details for DOI 10.1001/jamacardio.2020.0652
View details for Web of Science ID 000545603400012
View details for PubMedID 32320043
View details for PubMedCentralID PMC7177639
Native T1 Mapping, Extracellular Volume Mapping, and Late Gadolinium Enhancement in Cardiac Amyloidosis
2020; 13 (6): 1299-1310
This study aimed to compare the diagnostic and prognostic performance of native T1 mapping (T1), extracellular volume (ECV) mapping, and late gadolinium enhancement (LGE) imaging for evaluating cardiac amyloidosis (CA).CA is a progressive infiltrative process in the extracellular space that is often underdiagnosed and holds a poor prognosis. Cardiac magnetic resonance (CMR) offers novel techniques for detecting and quantifying the disease burden of CA.We searched PubMed for published studies using native T1, ECV, or LGE to diagnose and prognosticate CA. A total of 18 diagnostic (n = 2,015) and 13 prognostic studies (n = 1,483) were included for analysis. Pooled sensitivities, specificities, diagnostic odds ratios (DORs) of all diagnostic tests were assessed by bivariate analysis. Pooled hazard ratios (HRs) for mortality for the 3 techniques were determined.Bivariate comparison showed that ECV (DOR: 84.6; 95% confidence interval [CI]: 30.3 to 236.2) had a significantly higher DOR for CA than LGE (DOR: 20.1; 95% CI: 9.1 to 44.1; p = 0.03 vs. ECV). There was no significant difference between LGE and native T1 for sensitivity, specificity, and DOR. HR was significantly higher for ECV (HR: 4.27; 95% CI: 2.87 to 6.37) compared with LGE (HR: 2.60; 95% CI: 1.90 to 3.56; p = 0.03 vs. ECV) and native T1 (HR: 2.04; 95% CI: 1.24 to 3.37; p = 0.01 vs. ECV).ECV demonstrates a higher diagnostic OR for assessing cardiac amyloid than LGE and a higher HR for adverse events compared with LGE and native T1. In addition, native T1 showed similar sensitivity and specificity as ECV and LGE without requiring contrast material. Although limited by study heterogeneity, this meta-analysis suggests that ECV provides high diagnostic and prognostic utility for the assessment of cardiac amyloidosis.
View details for DOI 10.1016/j.jcmg.2020.03.010
View details for Web of Science ID 000547579300001
View details for PubMedID 32498919
View details for PubMedCentralID PMC7340140
T-1 mapping performance and measurement repeatability: results from the multi-national T-1 mapping standardization phantom program (T1MES)
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2020; 22 (1): 31
The T1 Mapping and Extracellular volume (ECV) Standardization (T1MES) program explored T1 mapping quality assurance using a purpose-developed phantom with Food and Drug Administration (FDA) and Conformité Européenne (CE) regulatory clearance. We report T1 measurement repeatability across centers describing sequence, magnet, and vendor performance.Phantoms batch-manufactured in August 2015 underwent 2 years of structural imaging, B0 and B1, and "reference" slow T1 testing. Temperature dependency was evaluated by the United States National Institute of Standards and Technology and by the German Physikalisch-Technische Bundesanstalt. Center-specific T1 mapping repeatability (maximum one scan per week to minimum one per quarter year) was assessed over mean 358 (maximum 1161) days on 34 1.5 T and 22 3 T magnets using multiple T1 mapping sequences. Image and temperature data were analyzed semi-automatically. Repeatability of serial T1 was evaluated in terms of coefficient of variation (CoV), and linear mixed models were constructed to study the interplay of some of the known sources of T1 variation.Over 2 years, phantom gel integrity remained intact (no rips/tears), B0 and B1 homogenous, and "reference" T1 stable compared to baseline (% change at 1.5 T, 1.95 ± 1.39%; 3 T, 2.22 ± 1.44%). Per degrees Celsius, 1.5 T, T1 (MOLLI 5s(3s)3s) increased by 11.4 ms in long native blood tubes and decreased by 1.2 ms in short post-contrast myocardium tubes. Agreement of estimated T1 times with "reference" T1 was similar across Siemens and Philips CMR systems at both field strengths (adjusted R2 ranges for both field strengths, 0.99-1.00). Over 1 year, many 1.5 T and 3 T sequences/magnets were repeatable with mean CoVs < 1 and 2% respectively. Repeatability was narrower for 1.5 T over 3 T. Within T1MES repeatability for native T1 was narrow for several sequences, for example, at 1.5 T, Siemens MOLLI 5s(3s)3s prototype number 448B (mean CoV = 0.27%) and Philips modified Look-Locker inversion recovery (MOLLI) 3s(3s)5s (CoV 0.54%), and at 3 T, Philips MOLLI 3b(3s)5b (CoV 0.33%) and Siemens shortened MOLLI (ShMOLLI) prototype 780C (CoV 0.69%). After adjusting for temperature and field strength, it was found that the T1 mapping sequence and scanner software version (both P < 0.001 at 1.5 T and 3 T), and to a lesser extent the scanner model (P = 0.011, 1.5 T only), had the greatest influence on T1 across multiple centers.The T1MES CE/FDA approved phantom is a robust quality assurance device. In a multi-center setting, T1 mapping had performance differences between field strengths, sequences, scanner software versions, and manufacturers. However, several specific combinations of field strength, sequence, and scanner are highly repeatable, and thus, have potential to provide standardized assessment of T1 times for clinical use, although temperature correction is required for native T1 tubes at least.
View details for DOI 10.1186/s12968-020-00613-3
View details for Web of Science ID 000533538100001
View details for PubMedID 32375896
View details for PubMedCentralID PMC7204222
Machine learning based quantification of ejection and filling parameters by fully automated dynamic measurement of left ventricular volumes from cardiac magnetic resonance images
MAGNETIC RESONANCE IMAGING
2020; 67: 28-32
Although analysis of cardiac magnetic resonance (CMR) images provides accurate and reproducible measurements of left ventricular (LV) volumes, these measurements are usually not performed throughout the cardiac cycle because of lack of tools that would allow such analysis within a reasonable timeframe. A fully-automated machine-learning (ML) algorithm was recently developed to automatically generate LV volume-time curves. Our aim was to validate ejection and filling parameters calculated from these curves using conventional analysis as a reference.We studied 21 patients undergoing clinical CMR examinations. LV volume-time curves were obtained using the ML-based algorithm (Neosoft), and independently using slice-by-slice, frame-by-frame manual tracing of the endocardial boundaries. Ejection and filling parameters derived from these curves were compared between the two techniques. For each parameter, Bland-Altman bias and limits of agreement (LOA) were expressed in percent of the mean measured value.Time-volume curves were generated using the automated ML analysis within 2.5 ± 0.5 min, considerably faster than the manual analysis (43 ± 14 min per patient, including ~10 slices with 25-32 frames per slice). Time-volume curves were similar between the two techniques in magnitude and shape. Size and function parameters extracted from these curves showed no significant inter-technique differences, reflected by high correlations, small biases (<10%) and mostly reasonably narrow LOA.ML software for dynamic LV volume measurement allows fast and accurate, fully automated analysis of ejection and filling parameters, compared to manual tracing based analysis. The ability to quickly evaluate time-volume curves is important for a more comprehensive evaluation of the patient's cardiac function.
View details for DOI 10.1016/j.mri.2019.12.004
View details for Web of Science ID 000517348300005
View details for PubMedID 31838116
View details for PubMedCentralID PMC7135920
MECHANISMS OF LEFT VENTRICULAR REMODELING AFTER CARDIAC RESYNCHRONIZATION THERAPY BASED ON POST DEVICE CARDIAC MAGNETIC RESONANCE IMAGING
ELSEVIER SCIENCE INC. 2020: 1825
View details for Web of Science ID 000522979101812
CIRCULATING FIBROCYTE LEVEL AS A MARKER OF MYOCARDIAL FIBROSIS FOLLOWING ACUTE ST ELEVATION MYOCARDIAL INFARCTION
ELSEVIER SCIENCE INC. 2020: 188
View details for Web of Science ID 000522979100184
- Multimodality Cardiovascular Imaging in the Midst of the COVID-19 Pandemic: Ramping Up Safely to a New Normal. JACC. Cardiovascular imaging 2020; 13 (7): 1615–26
A MYOCARDIAL T1-MAPPING FRAMEWORK WITH RECURRENT AND U-NET CONVOLUTIONAL NEURAL NETWORKS
IEEE. 2020: 1941-1944
View details for Web of Science ID 000578080300386
Severe combined cardiac and neuromuscular toxicity from immune checkpoint blockade: an institutional case series.
Cardio-oncology (London, England)
2020; 6: 21
Background: Immune checkpoint inhibition is part of standard systemic management for many advanced malignancies. Toxicities from this treatment approach are unpredictable, though usually reversible with management per established guidelines. Some patients suffer major morbidity and treatment-related mortality from these agents in an unpredictable manner. Cardiac and neurologic complications are rare, but can result in serious clinical consequences.Methods: We describe the presentation, management, and outcomes of eight sequential cases of combined cardiac and neurologic toxicities resulting in severe illness and demonstrating lack of rapid response to immunosuppression.Results: Our cohort consisted of six males and two females with an average age of 73.5years (61-89years). There were four patients with melanoma, and one patient each with urothelial carcinoma, renal cell carcinoma, breast cancer, and non-small cell lung cancer. Four patients received combination immunotherapy and four patients received monotherapy. The median time to presentation from treatment initiation was 27days (11-132days). All patients had a cardiovascular and neurologic toxicity, and most had hepatitis and myositis. The cardiac signs and symptoms were the prominent initial features of the clinical presentation. Each patient was managed by a multidisciplinary team and received a range of immunosuppressive agents. All patients died as a consequence of the immune related adverse events.Conclusions: The evaluation of patients with cardiac adverse events from immunotherapy, should include assessment of overlapping toxicities such as myasthenia gravis and myositis. Providers should be aware of the potential for an extended duration of disability and slow improvement for certain toxicities as these expectations may factor prominently in goals of care decisions.
View details for DOI 10.1186/s40959-020-00076-6
View details for PubMedID 32983574
- Cardiac Imaging in the Post-ISCHEMIA Trial Era: A Multisociety Viewpoint. JACC. Cardiovascular imaging 2020; 13 (8): 1815–33
Frequency of Coronary Microvascular Dysfunction and Diffuse Myocardial Fibrosis (Measured by Cardiovascular Magnetic Resonance) in Patients With Heart Failure and Preserved Left Ventricular Ejection Fraction
AMERICAN JOURNAL OF CARDIOLOGY
2019; 124 (10): 1584-1589
Heart failure with preserved ejection fraction (HFpEF) is frequently accompanied by co-morbidities and a systemic proinflammatory state, resulting in coronary microvascular dysfunction (CMD), as well as myocardial fibrosis. The purpose of this study is to examine the relation between myocardial perfusion reserve (MPR) and diffuse myocardial fibrosis in patients with HFpEF using cardiovascular magnetic resonance. A single center study was performed in 19 patients with clinical HFpEF and 15 healthy control subjects who underwent quantitative first-pass perfusion imaging to calculate global MPR. T1 mapping was used to assess fibrosis and to calculate extracellular volume. Spiral cine displacement encoded stimulated echo was used to calculate myocardial strain. Comprehensive 2D echocardiograms with speckle tracking, cardiopulmonary exercise testing, and brain natriuretic peptide levels were also obtained. In patients with HFpEF, mean left ventricular EF was 61% ± 9% and left ventricular mass index 45 ± 12 g/m2. Compared with controls, HFpEF patients had reduced global MPR (2.29 ± 0.64 vs 3.38 ± 0.76, p = 0.002) and VO2 max (16.5 ± 6.8 vs 30.9 ± 7.7 ml/kg min, p <0.001) whereas extracellular volume (0.29 ± 0.04 vs 0.25 ± 0.04, p = 0.02), pulmonary artery systolic pressure (35.4 ± 13.7 vs 22.3 ± 5.4 mm Hg, p = 0.004), and average E/e' (15.0 ± 7.6 vs 8.6 ± 2.0, p = 0.005) were increased. Displacement encoded stimulated echo peak systolic circumferential strain (p = 0.60) as well as echocardiographic derived global longitudinal strain (p = 0.07) were similar between both groups. The prevalence of CMD, defined as global MPR <2.5, in the HFpEF group was 69%. In conclusion, HFpEF patients have a high prevalence of CMD and diffuse fibrosis. These parameters may be useful clinical end points for future therapeutic trials.
View details for DOI 10.1016/j.amjcard.2019.08.011
View details for Web of Science ID 000499765300013
View details for PubMedID 31575425
View details for PubMedCentralID PMC6894613
Distinct Subgroups in Hypertrophic Cardiomyopathy in the NHLBI HCM Registry
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2019; 74 (19): 2333-2345
The HCMR (Hypertrophic Cardiomyopathy Registry) is a National Heart, Lung, and Blood Institute-funded, prospective registry of 2,755 patients with hypertrophic cardiomyopathy (HCM) recruited from 44 sites in 6 countries.The authors sought to improve risk prediction in HCM by incorporating cardiac magnetic resonance (CMR), genetic, and biomarker data.Demographic and echocardiographic data were collected. Patients underwent CMR including cine imaging, late gadolinium enhancement imaging (LGE) (replacement fibrosis), and T1 mapping for measurement of extracellular volume as a measure of interstitial fibrosis. Blood was drawn for the biomarkers N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (cTnT), and genetic analysis.A total of 2,755 patients were studied. Mean age was 49 ± 11 years, 71% were male, and 17% non-white. Mean ESC (European Society of Cardiology) risk score was 2.48 ± 0.56. Eighteen percent had a resting left ventricular outflow tract (LVOT) gradient ≥30 mm Hg. Thirty-six percent had a sarcomere mutation identified, and 50% had any LGE. Sarcomere mutation-positive patients were more likely to have reverse septal curvature morphology, LGE, and no significant resting LVOT obstruction. Those that were sarcomere mutation negative were more likely to have isolated basal septal hypertrophy, less LGE, and more LVOT obstruction. Interstitial fibrosis was present in segments both with and without LGE. Serum NT-proBNP and cTnT levels correlated with increasing LGE and extracellular volume in a graded fashion.The HCMR population has characteristics of low-risk HCM. Ninety-three percent had no or only mild functional limitation. Baseline data separated patients broadly into 2 categories. One group was sarcomere mutation positive and more likely had reverse septal curvature morphology, more fibrosis, but less resting obstruction, whereas the other was sarcomere mutation negative and more likely had isolated basal septal hypertrophy with obstruction, but less fibrosis. Further follow-up will allow better understanding of these subgroups and development of an improved risk prediction model incorporating all these markers.
View details for DOI 10.1016/j.jacc.2019.08.1057
View details for Web of Science ID 000494650000001
View details for PubMedID 31699273
View details for PubMedCentralID PMC6905038
Myocardial T1 and ECV Measurement Underlying Concepts and Technical Considerations
2019; 12 (11): 2332-2344
Myocardial native T1 and extracellular volume fraction (ECV) mapping have emerged as cardiac magnetic resonance biomarkers providing unique insight into cardiac pathophysiology. Single breath-hold acquisition techniques, available on clinical scanners across multiple vendor platforms, have made clinical T1 and ECV mapping a reality. Although the relationship between changes in native T1 and alterations in cardiac microstructure is complex, an understanding of how edema, blood volume, myocyte and interstitial expansion, lipids, and paramagnetic substances affect T1 and ECV can provide insight into how and why these parameters change in various cardiac pathologies. The goals of this state-of-the-art review will be to review factors influencing native T1 and ECV, to describe how native T1 and ECV are measured, to discuss potential challenges and pitfalls in clinical practice, and to describe new T1 mapping techniques on the horizon.
View details for DOI 10.1016/j.jcmg.2019.06.031
View details for Web of Science ID 000494948400005
View details for PubMedID 31542529
View details for PubMedCentralID PMC7008718
- Inline Quantitative Myocardial Perfusion by CMR Coming Online Soon? JACC-CARDIOVASCULAR IMAGING 2019; 12 (10): 1970-1972
Non-Cartesian slice-GRAPPA and slice-SPIRiT reconstruction methods for multiband spiral cardiac MRI
MAGNETIC RESONANCE IN MEDICINE
2020; 83 (4): 1235-1249
Spiral MRI has advantages for cardiac imaging, and multiband (MB) spiral MRI of the heart shows promise. However, current reconstruction methods for MB spiral imaging have limitations. We sought to develop improved reconstruction methods for MB spiral cardiac MRI.Two reconstruction methods were developed. The first is non-Cartesian slice-GRAPPA (NCSG), which uses phase demodulation and gridding operations before application of a Cartesian slice-separating kernel. The second method, slice-SPIRiT, formulates the reconstruction as a minimization problem that enforces in-plane coil consistency and consistency with the acquired MB data, and uses through-plane coil sensitivity information in the iterative solution. These methods were compared with conjugate-gradient SENSE in phantoms and volunteers. Temporal alternation of CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration) phase and the use of a temporal filter were also investigated.Phantom experiments with 3 simultaneous slices (MB = 3) showed that mean artifact power was highest for conjugate-gradient SENSE, lower for NCSG, and lowest for slice-SPIRiT. For volunteer cine imaging (MB = 3, N = 5), the artifact power was 0.182 ± 0.037, 0.148 ± 0.036, and 0.139 ± 0.034 for conjugate-gradient SENSE, NCSG, and slice-SPIRiT, respectively (P < .05, analysis of variance). Temporal alternation of CAIPIRINHA reduced artifacts for both NCSG and slice-SPIRiT.The NCSG and slice-SPIRiT methods provide more accurate reconstructions for MB spiral cine imaging compared with conjugate-gradient SENSE. These methods hold promise for non-Cartesian MB imaging.
View details for DOI 10.1002/mrm.28002
View details for Web of Science ID 000488056200001
View details for PubMedID 31565819
View details for PubMedCentralID PMC7797187
Free-breathing cine imaging with motion-corrected reconstruction at 3T using SPiral Acquisition with Respiratory correction and Cardiac Self-gating (SPARCS)
MAGNETIC RESONANCE IN MEDICINE
2019; 82 (2): 706-720
To develop a continuous-acquisition cardiac self-gated spiral pulse sequence and a respiratory motion-compensated reconstruction strategy for free-breathing cine imaging.Cine data were acquired continuously on a 3T scanner for 8 seconds per slice without ECG gating or breath-holding, using a golden-angle gradient echo spiral pulse sequence. Cardiac motion information was extracted by applying principal component analysis on the gridded 8 × 8 k-space center data. Respiratory motion was corrected by rigid registration on each heartbeat. Images were reconstructed using a low-rank and sparse (L+S) technique. This strategy was evaluated in 37 healthy subjects and 8 subjects undergoing clinical cardiac MR studies. Image quality was scored (1-5 scale) in a blinded fashion by 2 experienced cardiologists. In 13 subjects with whole-heart coverage, left ventricular ejection fraction (LVEF) from SPiral Acquisition with Respiratory correction and Cardiac Self-gating (SPARCS) was compared to that from a standard ECG-gated breath-hold balanced steady-state free precession (bSSFP) cine sequence.The self-gated signal was successfully extracted in all cases and demonstrated close agreement with the acquired ECG signal (mean bias, -0.22 ms). The mean image score across all subjects was 4.0 for reconstruction using the L+S model. There was good agreement between the LVEF derived from SPARCS and the gold-standard bSSFP technique.SPARCS successfully images cardiac function without the need for ECG gating or breath-holding. With an 8-second data acquisition per slice, whole-heart cine images with clinically acceptable spatial and temporal resolution and image quality can be acquired in <90 seconds of free-breathing acquisition.
View details for DOI 10.1002/mrm.27763
View details for Web of Science ID 000471308300015
View details for PubMedID 31006916
View details for PubMedCentralID PMC6510595
Cardiac MRI Endpoints in Myocardial Infarction Experimental and Clinical Trials JACC Scientific Expert Panel
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2019; 74 (2): 238-256
After a reperfused myocardial infarction (MI), dynamic tissue changes occur (edema, inflammation, microvascular obstruction, hemorrhage, cardiomyocyte necrosis, and ultimately replacement by fibrosis). The extension and magnitude of these changes contribute to long-term prognosis after MI. Cardiac magnetic resonance (CMR) is the gold-standard technique for noninvasive myocardial tissue characterization. CMR is also the preferred methodology for the identification of potential benefits associated with new cardioprotective strategies both in experimental and clinical trials. However, there is a wide heterogeneity in CMR methodologies used in experimental and clinical trials, including time of post-MI scan, acquisition protocols, and, more importantly, selection of endpoints. There is a need for standardization of these methodologies to improve the translation into a real clinical benefit. The main objective of this scientific expert panel consensus document is to provide recommendations for CMR endpoint selection in experimental and clinical trials based on pathophysiology and its association with hard outcomes.
View details for DOI 10.1016/j.jacc.2019.05.024
View details for Web of Science ID 000474425700011
View details for PubMedID 31296297
View details for PubMedCentralID PMC7363031
Venoarterial extracorporeal membrane oxygenation for acute massive pulmonary embolism: a systematic review and pooled analysis
SAGE PUBLICATIONS LTD. 2019: 280-281
View details for Web of Science ID 000469356500030
- HYBRID SURGICAL AND PERCUTANEOUS CORONARY INTERVENTION OF A GIANT CORONARY ARTERY ANEURYSM ELSEVIER SCIENCE INC. 2019: 2151
- CARDIAC MAGNETIC RESONANCE AFTER CRT DEMONSTRATES DISCORDANT EFFECTS ON RIGHT AND LEFT VENTRICULAR FUNCTION ELSEVIER SCIENCE INC. 2019: 1580
- Contemporary Issues in Quantitative Myocardial Perfusion CMR Imaging CURRENT CARDIOVASCULAR IMAGING REPORTS 2019; 12 (3)
Native T1 and Extracellular Volume Measurements by Cardiac MRI in Healthy Adults: A Meta-Analysis
2019; 290 (2): 317-326
Purpose To summarize the literature by performing a systematic review and pooled analysis of the data, to understand the extent of variability among studies of native T1 and extracellular volume (ECV) measurements, and to identify covariates that account for heterogeneity between studies. Materials and Methods PubMed, Web of Science, and Cochrane Central were searched for native T1 and ECV measurements of the left ventricle in health adult study participants. The search terms used were "T1 mapping heart," "Native T1 heart," and "ECV heart." Summary means were generated with random-effects modeling. Heterogeneity was assessed by using the inconsistency factor (I 2). Subgroup analyses and meta-regression analyses were conducted to identify etiologic causes of heterogeneity. Results This systematic review of native T1 included 120 articles, with 5541 participants (mean age, 50 years; 51.0% men [2826 of 5541]). The pooled mean of native T1 was 976 msec (95% confidence interval [CI]: 969 msec, 983 msec) at 1.5 T and 1159 msec (95% CI: 1143 msec, 1175 msec) at 3.0 T. I 2 was 99% at both field strengths. Eighty-one articles were included in the systematic review of ECV, with 3872 participants (mean age, 52 years; 50.0% men [1936 of 3872]). The pooled mean of ECV was 25.9% at field strength of 1.5 T (95% CI: 25.5%, 26.3%) and 3.0 T (95% CI: 25.4%, 26.5%). I 2 was 94% and 90% at 1.5 and 3.0 T, respectively. Conclusion The pooled means of extracellular volume and native T1 measurements in healthy adult participants are summarized in this analysis. There was significant heterogeneity found among studies, highlighting the importance of standardized cardiac MRI protocols and the derivation of institution specific reference ranges. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Dodd and Dewey in this issue.
View details for DOI 10.1148/radiol.2018180226
View details for Web of Science ID 000456444200009
View details for PubMedID 30422092
View details for PubMedCentralID PMC6358026
Whole-heart spiral simultaneous multi-slice first-pass myocardial perfusion imaging
MAGNETIC RESONANCE IN MEDICINE
2019; 81 (2): 852-862
To develop and evaluate a simultaneous multislice (SMS) spiral perfusion pulse sequence with whole-heart coverage.An orthogonal set of phase cycling angles following a Hadamard pattern was incorporated into a golden-angle (GA) variable density spiral perfusion sequence to perform SMS imaging at different multiband (MB) factors. Images were reconstructed using an SMS extension of L1-SPIRiT that we have termed SMS-L1-SPIRiT. The proposed sequence was evaluated in 40 subjects (10 each for MB factors of 1, 2, 3, and 4). Images were blindly graded by 2 cardiologists on a 5-point scale (5, excellent). To quantitatively evaluate the reconstruction performance against images acquired without SMS, the MB =1 data were used to retrospectively simulate data acquired at MB factors of 2 to 4.Analysis of the SMS point-spread function for the desired slice showed that the proposed sampling strategy significantly canceled the main-lobe energy of the other slices and has low side-lobe energy resulting in an incoherent temporal aliasing pattern when rotated by the GA. Retrospective experiments demonstrated the SMS-L1-SPIRiT method removed aliasing from the interfering slices and showed excellent agreement with the ground-truth MB =1 images. Clinical evaluation demonstrated high-quality perfusion images with average image-quality scores of 4.3 ± 0.5 (MB =2), 4.2 ± 0.5 (MB =3), and 4.4 ± 0.4 (MB =4) with no significant quality difference in image quality between MB factors (P = 0.38).SMS spiral perfusion at MB factors 2, 3, and 4 produces high-quality perfusion images with whole-heart coverage in a clinical setting with high sampling efficiency.
View details for DOI 10.1002/mrm.27412
View details for Web of Science ID 000462086300012
View details for PubMedID 30311689
View details for PubMedCentralID PMC6289615
Extracellular volume by cardiac magnetic resonance is associated with biomarkers of inflammation in hypertensive heart disease
JOURNAL OF HYPERTENSION
2019; 37 (1): 65-72
Cardiac magnetic resonance (CMR) provides a unique approach to the characterization of hypertensive heart disease (HHD), enabling the measurement of left ventricular mass and expansion of extracellular volume (ECV). Combining plasma biomarkers with CMR could provide potential insights into the pathophysiological mechanisms in ventricular remodelling.In this study, we estimated correlations between plasma biomarkers and CMR parameters of HHD. Patients with a history of hypertension with or without left ventricular hypertrophy (LVH) and healthy volunteers (17 hypertensive non-LVH, 13 hypertensive LVH and 11 controls) underwent CMR on a Siemens 1.5T Avanto. T1 mapping was performed before (native T1) and serially after injection of 0.15 mmol/kg gadolinium-DTPA. Mean ECV and left ventricular mass index (LVMI) were determined. Blood samples were obtained and analysed using the Olink CVD 92-plex biomarker panel.Individual groups were compared on the basis of 91 plasma biomarkers using partial least squares discriminant analysis (PLS-DA). ECV and LVMI were correlated with the 91 distinct plasma biomarkers via orthogonal projection to latent structures by partial least square (OPLS) analysis. A two-dimensional PLS-DA explained 49% of the differences between the three groups. OPLS analysis showed that four plasma biomarkers were significantly correlated to both ECV and LVMI, eight were significantly correlated with LVMI only and 11 were significantly correlated to ECV only.ECV and LVMI correlate differentially in plasma biomarker patterns. Top predictors of ECV consisted of well established biomarkers of systemic inflammation and metabolic function.
View details for DOI 10.1097/HJH.0000000000001875
View details for Web of Science ID 000467336300014
View details for PubMedID 30063646
Cardiac MRI for the evaluation of oncologic cardiotoxicity
JOURNAL OF NUCLEAR CARDIOLOGY
2018; 25 (6): 2148-2158
Cancer therapeutics-related cardiac dysfunction (CTRCD) is a well-established adverse effect resulting from a number of cancer therapeutics. Newer immunotherapy has been associated with cardiomyopathy and myocarditis making comprehensive imaging useful for early recognition. Cardiac MRI (CMR) offers a comprehensive evaluation to detect CTRCD. Established guidelines for monitoring left ventricular ejection fraction for potential cardiotoxicity have recently incorporated CMR. We will review the utility of CMR in contemporary evaluation for potential oncologic cardiotoxicity.
View details for DOI 10.1007/s12350-018-1293-9
View details for Web of Science ID 000452340400044
View details for PubMedID 29736616
View details for PubMedCentralID PMC6222005
Role of Cardiac Magnetic Resonance Imaging in Valvular Heart Disease: Diagnosis, Assessment, and Management
CURRENT CARDIOLOGY REPORTS
2018; 20 (11): 119
This article will review the current techniques in cardiac magnetic resonance imaging (CMR) for diagnosing and assessing primary valvular heart disease.The recent advancements in CMR have led to an increased role of this modality for qualifying and quantifying various native valve diseases. Phase-contrast velocity encoded imaging is a well-established technique that can be used to quantify aortic and pulmonic flow. This technique, combined with the improved ability for CMR to obtain accurate left and right ventricular volumetrics, has allowed for increased accuracy and reproducibility in assessing valvular dysfunction. Advancements in CMR technology also allows for improved spatial and temporal resolution imaging of various valves and their regurgitant or stenotic jets. Therefore, CMR can be a powerful tool in evaluation of native valvular heart disease. The role of CMR in assessing valvular heart disease is growing and being recognized in recent guidelines. CMR has the ability to assess valve morphology along with qualifying and quantifying valvular disease. In addition, the ability to obtain accurate volumetric measurements may improve more precise management strategies and may lead to improvements in mortality and morbidity.
View details for DOI 10.1007/s11886-018-1057-9
View details for Web of Science ID 000445744600008
View details for PubMedID 30259253
View details for PubMedCentralID PMC6415765
Content-aware compressive magnetic resonance image reconstruction
MAGNETIC RESONANCE IMAGING
2018; 52: 118-130
This paper describes an adaptive approach to regularizing model-based reconstructions in magnetic resonance imaging to account for local structure or image content. In conjunction with common models like wavelet and total variation sparsity, this content-aware regularization avoids oversmoothing or compromising image features while suppressing noise and incoherent aliasing from accelerated imaging. To evaluate this regularization approach, the experiments reconstruct images from single- and multi-channel, Cartesian and non-Cartesian, brain and cardiac data. These reconstructions combine common analysis-form regularizers and autocalibrating parallel imaging (when applicable). In most cases, the results show widespread improvement in structural similarity and peak-signal-to-error ratio relative to the fully sampled images. These results suggest that this content-aware regularization can preserve local image structures such as edges while providing denoising power superior to sparsity-promoting or sparsity-reweighted regularization.
View details for DOI 10.1016/j.mri.2018.06.008
View details for Web of Science ID 000443105000014
View details for PubMedID 29935257
View details for PubMedCentralID PMC6102097
- Risk Stratification in Nonischemic Dilated Cardiomyopathy in the Era of Personalized Medicine Can Cardiac Magnetic Resonance With Late Gadolinium Imaging "Enhance" Our Strategy? JACC-CARDIOVASCULAR IMAGING 2018; 11 (9): 1285-1287
Recurrent Myocarditis Imitating ST Segment Elevation Myocardial Infarction.
Journal of medical cases
2018; 9 (8): 239-242
Acute myocarditis mimicking ST segment elevation myocardial infarction is a well-known phenomenon, but recurrence and progression are rare. We present a case of a 29-year-old man with three episodes of myocarditis over 3 months including evidence of progressive, patchy inflammation shown by cardiovascular magnetic resonance imaging.
View details for DOI 10.14740/jmc3081w
View details for PubMedID 30906487
Diagnostic Performance of Extracellular Volume, Native T1, and T2 Mapping Versus Lake Louise Criteria by Cardiac Magnetic Resonance for Detection of Acute Myocarditis: A Meta-Analysis
2018; 11 (7): e007598
The Lake Louise Criteria (LLC) were established in 2009 and are the recommended cardiac magnetic resonance imaging criterion for diagnosing patients with suspected myocarditis. Subsequently, newer parametric imaging techniques which can quantify T1, T2, and the extracellular volume (ECV) have been developed and may provide additional utility in the diagnosis of myocarditis. However, whether their diagnostic accuracy is superior to LLC remains unclear. In this meta-analysis, we compared the diagnostic performance of native T1, T2, ECV to LLC in diagnosing acute myocarditis.We searched PubMed for published studies of LLC, native T1, ECV, and T2 diagnostic criteria used to diagnose acute myocarditis. Seventeen studies were included, with a total of 867 myocarditis patients and 441 control subjects. Pooled sensitivity, specificity, and diagnostic odds ratio of all diagnostic tests were assessed by bivariate analysis. LLC had a pooled sensitivity of 74%, specificity of 86%, and diagnostic odds ratio of 17.7. Native T1 had a significantly higher sensitivity than LLC (85% versus 74%, P=0.025). Otherwise, there was no significant difference in sensitivity, specificity, and diagnostic odds ratio when comparing LLC to native T1, T2, or ECV.Native T1, T2, and ECV mapping provide comparable diagnostic performance to LLC. Although only native T1 had significantly better sensitivity than LLC, each technique offers distinct advantages for evaluating and characterizing myocarditis when compared with the LLC.
View details for DOI 10.1161/CIRCIMAGING.118.007598
View details for Web of Science ID 000438923700007
View details for PubMedID 30012826
View details for PubMedCentralID PMC6192699
Simple motion correction strategy reduces respiratory-induced motion artifacts for k-t accelerated and compressed-sensing cardiovascular magnetic resonance perfusion imaging (vol 20, 6, 2018)
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2018; 20: 23
Figure 1 of this original publication contained a minor error as one of the lines in the "Reconstruction pipline" was not visible. The updated Fig. 1 is published in this correction article.
View details for DOI 10.1186/s12968-018-0439-x
View details for Web of Science ID 000428517100001
View details for PubMedID 29576016
View details for PubMedCentralID PMC5868071
Quantitative cardiovascular magnetic resonance perfusion imaging identifies reduced flow reserve in microvascular coronary artery disease
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2018; 20: 14
Preliminary semi-quantitative cardiovascular magnetic resonance (CMR) perfusion studies have demonstrated reduced myocardial perfusion reserve (MPR) in patients with angina and risk factors for microvascular disease (MVD), however fully quantitative CMR has not been studied. The purpose of this study is to evaluate whether fully quantitative CMR identifies reduced MPR in this population, and to investigate the relationship between epicardial atherosclerosis, left ventricular hypertrophy (LVH), extracellular volume (ECV), and perfusion.Forty-six patients with typical angina and risk factors for MVD (females, or males with diabetes or metabolic syndrome) who had no obstructive coronary artery disease by coronary angiography and 20 healthy control subjects underwent regadenoson stress CMR perfusion imaging using a dual-sequence quantitative spiral pulse sequence to quantify MPR. Subjects also underwent T1 mapping to quantify ECV, and computed tomographic (CT) coronary calcium scoring to assess atherosclerosis burden.In patients with risk factors for MVD, both MPR (2.21 [1.95,2.69] vs. 2.93 [2.763.19], p < 0.001) and stress myocardial perfusion (2.65 ± 0.62 ml/min/g, vs. 3.17 ± 0.49 ml/min/g p < 0.002) were reduced as compared to controls. These differences remained after adjusting for age, left ventricular (LV) mass, body mass index (BMI), and gender. There were no differences in native T1 or ECV between subjects and controls.Stress myocardial perfusion and MPR as measured by fully quantitative CMR perfusion imaging are reduced in subjects with risk factors for MVD with no obstructive CAD as compared to healthy controls. Neither myocardial hypertrophy nor fibrosis accounts for these differences.
View details for DOI 10.1186/s12968-018-0435-1
View details for Web of Science ID 000425768500001
View details for PubMedID 29471856
View details for PubMedCentralID PMC5822618
Clinical recommendations for cardiovascular magnetic resonance mapping of T1, T2, T2* and extracellular volume: A consensus statement by the Society for Cardiovascular Magnetic Resonance (SCMR) endorsed by the European Association for Cardiovascular Imaging (EACVI) (vol 19, 75, 2017)
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2018; 20: 9
J CARDIOVASC MAGN RESON (2017) 19: 75. DOI: 10.1186/S12968-017-0389-8: In the original publication of this article  the "Competing interests" section was incorrect. The original publication stated the following competing interests.
View details for DOI 10.1186/s12968-017-0408-9
View details for Web of Science ID 000424709900001
View details for PubMedID 29415744
View details for PubMedCentralID PMC5804075
- Feature Tracking by CMR A "Double Feature"? JACC-CARDIOVASCULAR IMAGING 2018; 11 (2): 206-208
Simple motion correction strategy reduces respiratory-induced motion artifacts for k-t accelerated and compressed-sensing cardiovascular magnetic resonance perfusion imaging
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2018; 20: 6
Cardiovascular magnetic resonance (CMR) stress perfusion imaging provides important diagnostic and prognostic information in coronary artery disease (CAD). Current clinical sequences have limited temporal and/or spatial resolution, and incomplete heart coverage. Techniques such as k-t principal component analysis (PCA) or k-t sparcity and low rank structure (SLR), which rely on the high degree of spatiotemporal correlation in first-pass perfusion data, can significantly accelerate image acquisition mitigating these problems. However, in the presence of respiratory motion, these techniques can suffer from significant degradation of image quality. A number of techniques based on non-rigid registration have been developed. However, to first approximation, breathing motion predominantly results in rigid motion of the heart. To this end, a simple robust motion correction strategy is proposed for k-t accelerated and compressed sensing (CS) perfusion imaging.A simple respiratory motion compensation (MC) strategy for k-t accelerated and compressed-sensing CMR perfusion imaging to selectively correct respiratory motion of the heart was implemented based on linear k-space phase shifts derived from rigid motion registration of a region-of-interest (ROI) encompassing the heart. A variable density Poisson disk acquisition strategy was used to minimize coherent aliasing in the presence of respiratory motion, and images were reconstructed using k-t PCA and k-t SLR with or without motion correction. The strategy was evaluated in a CMR-extended cardiac torso digital (XCAT) phantom and in prospectively acquired first-pass perfusion studies in 12 subjects undergoing clinically ordered CMR studies. Phantom studies were assessed using the Structural Similarity Index (SSIM) and Root Mean Square Error (RMSE). In patient studies, image quality was scored in a blinded fashion by two experienced cardiologists.In the phantom experiments, images reconstructed with the MC strategy had higher SSIM (p < 0.01) and lower RMSE (p < 0.01) in the presence of respiratory motion. For patient studies, the MC strategy improved k-t PCA and k-t SLR reconstruction image quality (p < 0.01). The performance of k-t SLR without motion correction demonstrated improved image quality as compared to k-t PCA in the setting of respiratory motion (p < 0.01), while with motion correction there is a trend of better performance in k-t SLR as compared with motion corrected k-t PCA.Our simple and robust rigid motion compensation strategy greatly reduces motion artifacts and improves image quality for standard k-t PCA and k-t SLR techniques in setting of respiratory motion due to imperfect breath-holding.
View details for DOI 10.1186/s12968-018-0427-1
View details for Web of Science ID 000423717800001
View details for PubMedID 29386056
View details for PubMedCentralID PMC5793398
Evolution of diastolic function algorithms: Implications for clinical practice
ECHOCARDIOGRAPHY-A JOURNAL OF CARDIOVASCULAR ULTRASOUND AND ALLIED TECHNIQUES
2018; 35 (1): 39-46
We undertook this study of echocardiographic classification of diastolic function by three different algorithms to determine: (1) how frequently each algorithm classified patients and (2) how well the results agreed with one another.Several algorithms exist to grade diastolic function (DF), the Mayo Clinic scheme of Redfield et al (Mayo 2003) and the 2 ASE guideline documents of 2009 and 2016 (ASE 2009 and ASE 2016).A total of 200 consecutive echocardiograms were retrospectively analyzed; mean age of patients 60.3 ± 3.5 years, 45% male. Echocardiograms were performed using Intersocietal Accreditation Commission guidelines. Diastolic function was assessed by Mayo 2003 and ASE 2009 and 2016. Coexisting conditions affecting DF analysis, such as mitral annular calcification (MAC), were tabulated. Data were compared using a paired t-test. Concordance between algorithms was assessed using the Kappa statistic.A total of 117 of 200 studies (58.5%) were excluded for the presence of coexisting conditions (51.5%), poor image quality (2.5%), or incomplete data (4.5%). Thirty-three of the remaining 83 studies (40%) received the same grade of DF based on assessments made using the Mayo 2003 and ASE 2016 algorithms; the Kappa statistic was 0.20. 36 of the 83 studies (43%) received the same grade of DF based on assessments made using the ASE 2009 and ASE 2016 algorithms; the Kappa statistic was 0.25.Assessment of diastolic function via echocardiography cannot be reliably accomplished in approximately 50% of patients using current guidelines. Further, when studies are suitable for assessment, widely used guidelines yield discordant results.
View details for DOI 10.1111/echo.13746
View details for Web of Science ID 000422684900006
View details for PubMedID 29178212
IMAGE QUALITY AFFECTS DEEP LEARNING RECONSTRUCTION OF MRI
IEEE. 2018: 357-360
View details for Web of Science ID 000455045600081
Computed Tomography Fractional Flow Reserve to Guide Coronary Angiography and Intervention.
Interventional cardiology clinics
2018; 7 (3): 345-354
Computed tomography angiography (CTA) has played a significant role in evaluation of coronary artery disease in the last decade and has demonstrated high sensitivity and negative predictive values. However, the positive predictive value as compared with invasive fractional flow reserve (FFR) is limited. CT-FFR has emerged as a disruptive noninvasive technology with higher specificity and diagnostic accuracy for detection of hemodynamically significant coronary lesions as compared with invasive FFR than conventional coronary CTA. CT-FFR has been shown to be cost-effective as a gate-keeper to invasive coronary angiography and has the potential to limit unnecessary invasive angiography studies.
View details for DOI 10.1016/j.iccl.2018.03.008
View details for PubMedID 29983146
Reduced field of view single-shot spiral perfusion imaging
MAGNETIC RESONANCE IN MEDICINE
2018; 79 (1): 208-216
To develop a single-shot spiral perfusion pulse sequence with outer-volume suppression (OVS) to achieve whole-heart coverage with a short temporal footprint of 10 ms per slice location.A highly accelerated single-shot variable density spiral pulse sequence with an integrated OVS module for reduced field of view (rFOV) perfusion imaging with 2 mm spatial resolution was developed and evaluated in simulations, phantom experiments and in clinical patients with (n = 8) or without (n = 8) OVS. Images were reconstructed by block low-rank sparsity with motion guidance (BLOSM) and graded by two cardiologists on a 5-point scale (1, excellent; 5, poor).Simulation and phantom results showed that OVS effectively suppressed the signal outside the desired field of view (FOV). Clinical patient data demonstrated high quality perfusion images with rFOV. The average image quality scores of full FOV cases and rFOV cases were 3.1 ± 0.64 and 2.3 ± 0.46, respectively, (P = 0.02) from cardiologist 1 and 2.5 ± 0.54 and 1.8 ± 0.47, respectively, (P = 0.04) from cardiologist 2, showing superior image quality for the rFOV images compared with the full FOV images.A single-shot spiral perfusion sequence that uses OVS and BLOSM performs perfusion imaging with a very short temporal footprint per image supporting whole-heart coverage with good image quality. Magn Reson Med 79:208-216, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
View details for DOI 10.1002/mrm.26664
View details for Web of Science ID 000417926300019
View details for PubMedID 28321908
View details for PubMedCentralID PMC5607067
- Change In Paravalvular Leak Following CoreValve versus Sapien Aortic Valve Replacement ELSEVIER SCIENCE INC. 2017: B197-B198
Clinical recommendations for cardiovascular magnetic resonance mapping of T1, T2, T2*and extracellular volume: A consensus statement by the Society for Cardiovascular Magnetic Resonance (SCMR) endorsed by the European Association for Cardiovascular Imaging (EACVI)
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2017; 19: 75
Parametric mapping techniques provide a non-invasive tool for quantifying tissue alterations in myocardial disease in those eligible for cardiovascular magnetic resonance (CMR). Parametric mapping with CMR now permits the routine spatial visualization and quantification of changes in myocardial composition based on changes in T1, T2, and T2*(star) relaxation times and extracellular volume (ECV). These changes include specific disease pathways related to mainly intracellular disturbances of the cardiomyocyte (e.g., iron overload, or glycosphingolipid accumulation in Anderson-Fabry disease); extracellular disturbances in the myocardial interstitium (e.g., myocardial fibrosis or cardiac amyloidosis from accumulation of collagen or amyloid proteins, respectively); or both (myocardial edema with increased intracellular and/or extracellular water). Parametric mapping promises improvements in patient care through advances in quantitative diagnostics, inter- and intra-patient comparability, and relatedly improvements in treatment. There is a multitude of technical approaches and potential applications. This document provides a summary of the existing evidence for the clinical value of parametric mapping in the heart as of mid 2017, and gives recommendations for practical use in different clinical scenarios for scientists, clinicians, and CMR manufacturers.
View details for DOI 10.1186/s12968-017-0389-8
View details for Web of Science ID 000412512700001
View details for PubMedID 28992817
View details for PubMedCentralID PMC5633041
- A Novel Index of Remodeling in Hypertensive Heart Disease CIRCULATION-CARDIOVASCULAR IMAGING 2017; 10 (9)
Imaging Left-Ventricular Mechanical Activation in Heart Failure Patients Using Cine DENSE MRI: Validation and Implications for Cardiac Resynchronization Therapy
JOURNAL OF MAGNETIC RESONANCE IMAGING
2017; 46 (3): 887-896
To image late mechanical activation and identify effective left-ventricular (LV) pacing sites for cardiac resynchronization therapy (CRT). There is variability in defining mechanical activation time, with some studies using the time to peak strain (TPS) and some using the time to the onset of circumferential shortening (TOS). We developed improved methods for imaging mechanical activation and evaluated them in heart failure (HF) patients undergoing CRT.We applied active contours to cine displacement encoding with stimulated echoes (DENSE) strain images to detect TOS. Six healthy volunteers underwent magnetic resonance imaging (MRI) at 1.5T, and 50 patients underwent pre-CRT MRI (strain, scar, volumes) and echocardiography, assessment of the electrical activation time (Q-LV) at the LV pacing site, and echocardiography assessment of LV reverse remodeling 6 months after CRT. TPS at the LV pacing site was also measured by DENSE.The latest TOS was greater in HF patients vs. healthy subjects (112 ± 28 msec vs. 61 ± 7 msec, P < 0.01). The correlation between TOS and Q-LV was strong (r > 0.75; P < 0.001) and better than between TPS and Q-LV (r < 0.62; P ≥ 0.006). Twenty-three of 50 patients had the latest activating segment in a region other than the mid-ventricular lateral wall, the most common site for the CRT LV lead. Using a multivariable model, TOS/QRS was significantly associated with LV reverse remodeling even after adjustment for overall dyssynchrony and scar (P < 0.05), whereas TPS was not (P = 0.49).Late activation by cine DENSE TOS analysis is associated with improved LV reverse remodeling with CRT and deserves further study as a tool to achieve optimal LV lead placement in CRT.1 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:887-896.
View details for DOI 10.1002/jmri.25613
View details for Web of Science ID 000409283000026
View details for PubMedID 28067978
View details for PubMedCentralID PMC5502204
- Multidisciplinary Clinic to Identify Near Misses and Decrease Readmission Rates After Hospitalization for Myocardial Infarction CIRCULATION-CARDIOVASCULAR QUALITY AND OUTCOMES 2017; 10 (9)
Recent Advances in Cardiovascular Magnetic Resonance Techniques and Applications
2017; 10 (6)
Cardiovascular magnetic resonance imaging has become the gold standard for evaluating myocardial function, volumes, and scarring. Additionally, cardiovascular magnetic resonance imaging is unique in its comprehensive tissue characterization, including assessment of myocardial edema, myocardial siderosis, myocardial perfusion, and diffuse myocardial fibrosis. Cardiovascular magnetic resonance imaging has become an indispensable tool in the evaluation of congenital heart disease, heart failure, cardiac masses, pericardial disease, and coronary artery disease. This review will highlight some recent novel cardiovascular magnetic resonance imaging techniques, concepts, and applications.
View details for DOI 10.1161/CIRCIMAGING.116.003951
View details for Web of Science ID 000403648800001
View details for PubMedID 28611116
View details for PubMedCentralID PMC5777859
Multiparametric CMR imaging of infarct remodeling in a percutaneous reperfused Yucatan mini-pig model
NMR IN BIOMEDICINE
2017; 30 (5)
To further understanding of the temporal evolution and pathophysiology of adverse ventricular remodeling over the first 60 days following a myocardial infarction (MI) in both the infarcted and remote myocardium, we performed multi-parametric cardiac magnetic resonance (CMR) imaging in a closed-chest chronic Yucatan mini-pig model of reperfused MI. Ten animals underwent 90 min left anterior descending artery occlusion and reperfusion. Three animals served as controls. Multiparametric CMR (1.5T) was performed at baseline, Day 2, Day 30 and in four animals on Day 60 after MI. Left ventricular (LV) volumes and infarct size were measured. T1 and T2 mapping sequences were performed to measure values in the infarct and remote regions. Remote region collagen fractions were compared between infarcted animals and controls. Procedure success was 80%. The model created large infarcts (28 ± 5% of LV mass on Day 2), which led to significant adverse myocardial remodeling that stabilized beyond 30 days. Native T1 values did not reliably differentiate remote and infarct regions acutely. There was no evidence of remote fibrosis as indicated by partition coefficient and collagen fraction analyses. The infarct T2 values remained elevated up to 60 days after MI. Multiparametric CMR in this model showed significant adverse ventricular remodeling 30 days after MI similar to that seen in humans. In addition, this study demonstrated that remote fibrosis is absent and that infarct T2 signal remains chronically elevated in this model. These findings need to be considered when designing preclinical trials using CMR endpoints.
View details for DOI 10.1002/nbm.3693
View details for Web of Science ID 000399311900009
View details for PubMedID 28164391
View details for PubMedCentralID PMC5488275
Prognostic Value of Myocardial Scarring on CMR in Patients With Cardiac Sarcoidosis
2017; 10 (4): 411-420
This study sought to perform a systematic review and meta-analysis to understand the prognostic value of myocardial scarring as evidenced by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging in patients with known or suspected cardiac sarcoidosis.Although CMR is increasingly used for the diagnosis of cardiac sarcoidosis, the prognostic value of CMR has been less well described in this population.PubMed, Cochrane CENTRAL, and metaRegister of Controlled Trials were searched for CMR studies with ≥1 year of prognostic data. Primary endpoints were all-cause mortality and a composite outcome of arrhythmogenic events (ventricular arrhythmia, implantable cardioverter-defibrillator shock, sudden cardiac death) plus all-cause mortality during follow-up. Summary effect estimates were generated with random-effects modeling.Ten studies were included, involving a total of 760 patients with a mean follow-up of 3.0 ± 1.1 years. Patients had a mean age of 53 years, 41% were male, 95.3% had known extracardiac sarcoidosis, and 21.6% had known cardiac sarcoidosis. The average ejection fraction was 57.8 ± 9.1%. Patients with LGE had higher odds for all-cause mortality (odds ratio [OR]: 3.06; p < 0.03) and higher odds of the composite outcome (OR: 10.74; p < 0.00001) than those without LGE. Patients with LGE had an increased annualized event rate of the composite outcome (11.9% vs. 1.1%; p < 0.0001).In patients with known or suspected cardiac sarcoidosis, the presence of LGE on CMR imaging is associated with increased odds of both all-cause mortality and arrhythmogenic events.
View details for DOI 10.1016/j.jcmg.2016.05.009
View details for Web of Science ID 000399960300005
View details for PubMedID 27450877
View details for PubMedCentralID PMC5237422
- RECURRENT FOCAL MYOCARDITIS WITH MICROVASCULAR OBSTRUCTION ELSEVIER SCIENCE INC. 2017: 2171
PREDICTION OF 30 DAY READMISSIONS IN PATIENTS ADMITTED FOR ACUTE MYOCARDIAL INFARCTION (AMI)
ELSEVIER SCIENCE INC. 2017: 228
View details for Web of Science ID 000397342300229
First-Pass Myocardial Perfusion Imaging with Whole-Heart Coverage Using L1-SPIRiT Accelerated Variable Density Spiral Trajectories
MAGNETIC RESONANCE IN MEDICINE
2016; 76 (5): 1375-1387
To design and evaluate two-dimensional (2D) L1-SPIRiT accelerated spiral pulse sequences for first-pass myocardial perfusion imaging with whole heart coverage capable of measuring eight slices at 2 mm in-plane resolution at heart rates up to 125 beats per minute (BPM).Combinations of five different spiral trajectories and four k-t sampling patterns were retrospectively simulated in 25 fully sampled datasets and reconstructed with L1-SPIRiT to determine the best combination of parameters. Two candidate sequences were prospectively evaluated in 34 human subjects to assess in vivo performance.A dual density broad transition spiral trajectory with either angularly uniform or golden angle in time k-t sampling pattern had the largest structural similarity and smallest root mean square error from the retrospective simulation, and the L1-SPIRiT reconstruction had well-preserved temporal dynamics. In vivo data demonstrated that both of the sampling patterns could produce high quality perfusion images with whole-heart coverage.First-pass myocardial perfusion imaging using accelerated spirals with optimized trajectory and k-t sampling pattern can produce high quality 2D perfusion images with whole-heart coverage at the heart rates up to 125 BPM. Magn Reson Med 76:1375-1387, 2016. © 2015 International Society for Magnetic Resonance in Medicine.
View details for DOI 10.1002/mrm.26014
View details for Web of Science ID 000389127100004
View details for PubMedID 26538511
View details for PubMedCentralID PMC4860174
A medical device-grade T1 and ECV phantom for global T1 mapping quality assurance-the T-1 Mapping and ECV Standardization in cardiovascular magnetic resonance (T1MES) program
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2016; 18: 58
T1 mapping and extracellular volume (ECV) have the potential to guide patient care and serve as surrogate end-points in clinical trials, but measurements differ between cardiovascular magnetic resonance (CMR) scanners and pulse sequences. To help deliver T1 mapping to global clinical care, we developed a phantom-based quality assurance (QA) system for verification of measurement stability over time at individual sites, with further aims of generalization of results across sites, vendor systems, software versions and imaging sequences. We thus created T1MES: The T1 Mapping and ECV Standardization Program.A design collaboration consisting of a specialist MRI small-medium enterprise, clinicians, physicists and national metrology institutes was formed. A phantom was designed covering clinically relevant ranges of T1 and T2 in blood and myocardium, pre and post-contrast, for 1.5 T and 3 T. Reproducible mass manufacture was established. The device received regulatory clearance by the Food and Drug Administration (FDA) and Conformité Européene (CE) marking.The T1MES phantom is an agarose gel-based phantom using nickel chloride as the paramagnetic relaxation modifier. It was reproducibly specified and mass-produced with a rigorously repeatable process. Each phantom contains nine differently-doped agarose gel tubes embedded in a gel/beads matrix. Phantoms were free of air bubbles and susceptibility artifacts at both field strengths and T1 maps were free from off-resonance artifacts. The incorporation of high-density polyethylene beads in the main gel fill was effective at flattening the B 1 field. T1 and T2 values measured in T1MES showed coefficients of variation of 1 % or less between repeat scans indicating good short-term reproducibility. Temperature dependency experiments confirmed that over the range 15-30 °C the short-T1 tubes were more stable with temperature than the long-T1 tubes. A batch of 69 phantoms was mass-produced with random sampling of ten of these showing coefficients of variations for T1 of 0.64 ± 0.45 % and 0.49 ± 0.34 % at 1.5 T and 3 T respectively.The T1MES program has developed a T1 mapping phantom to CE/FDA manufacturing standards. An initial 69 phantoms with a multi-vendor user manual are now being scanned fortnightly in centers worldwide. Future results will explore T1 mapping sequences, platform performance, stability and the potential for standardization.
View details for DOI 10.1186/s12968-016-0280-z
View details for Web of Science ID 000386466400001
View details for PubMedID 27660042
View details for PubMedCentralID PMC5034411
Clinical Utility and Future Applications of PET/CT and PET/CMR in Cardiology
2016; 6 (3)
Over the past several years, there have been major advances in cardiovascular positron emission tomography (PET) in combination with either computed tomography (CT) or, more recently, cardiovascular magnetic resonance (CMR). These multi-modality approaches have significant potential to leverage the strengths of each modality to improve the characterization of a variety of cardiovascular diseases and to predict clinical outcomes. This review will discuss current developments and potential future uses of PET/CT and PET/CMR for cardiovascular applications, which promise to add significant incremental benefits to the data provided by each modality alone.
View details for DOI 10.3390/diagnostics6030032
View details for Web of Science ID 000383833900006
View details for PubMedID 27598207
View details for PubMedCentralID PMC5039566
Robust free-breathing SASHA T-1 mapping with high-contrast image registration
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2016; 18: 47
Many widely used myocardial T1 mapping sequences use breath-hold acquisitions that limit the precision of calculated T1 maps. The SAturation-recovery single-SHot Acquisition (SASHA) sequence has high accuracy with robustness against systematic confounders, but has poorer precision compared to the commonly used MOdified Look-Locker Inversion recovery (MOLLI) sequence. We propose a novel method for generating high-contrast SASHA images to enable a robust image registration approach to free-breathing T1 mapping with high accuracy and precision.High-contrast (HC) images were acquired in addition to primary variable flip angle (VFA) SASHA images by collecting an additional 15 k-space lines and sharing k-space data with the primary image. The number of free-breathing images and their saturation recovery times were optimized through numerical simulations. Accuracy and precision of T1 maps using the proposed SASHA-HC sequence was compared in 10 volunteers at 1.5 T to MOLLI, a breath-hold SASHA-VFA sequence, and free-breathing SASHA-VFA data processed using conventional navigator gating and standard image registration. Free-breathing T1 maps from 15 patients and 10 volunteers were graded by blinded observers for sharpness and artifacts.Difference images calculated by subtracting HC and primary SASHA images had greater tissue-blood contrast than the primary images alone, with a 3× improvement for 700 ms TS saturation recovery images and a 6× increase in tissue-blood contrast for non-saturated images. Myocardial T1s calculated in volunteers with free-breathing SASHA-HC were similar to standard breath-hold SASHA-VFA (1156.1 ± 28.1 ms vs 1149.4 ± 26.5 ms, p >0.05). The standard deviation of myocardial T1 values using a 108 s free-breathing SASHA-HC (36.2 ± 3.1 ms) was 50 % lower (p <0.01) than breath-hold SASHA-VFA (72.7 ± 8.0 ms) and 34 % lower (p <0.01) than breath-hold MOLLI (54.7 ± 5.9 ms). T1 map quality scores in volunteers were higher with SASHA-HC (4.7 ± 0.3 out of 5) than navigator gating (3.6 ± 0.4, p <0.01) or normal registration (3.7 ± 0.4, p <0.01). SASHA-HC T1 maps had comparable precision to breath-hold MOLLI using a retrospectively down-sampled 30 s free-breathing acquisition and 30 % higher precision with a 60 s acquisition.High-contrast SASHA images enable a robust image registration approach to free-breathing T1 mapping. Free-breathing SASHA-HC provides accurate T1 maps with higher precision than MOLLI in acquisitions longer than 30 s.
View details for DOI 10.1186/s12968-016-0267-9
View details for Web of Science ID 000383226600001
View details for PubMedID 27535744
View details for PubMedCentralID PMC4989502
Anthracycline- and trastuzumab-induced cardiotoxicity: a retrospective study
2016; 33 (7): 82
Some chemotherapeutic agents cause cardiotoxic effects including reduction in left ventricular ejection fraction (LVEF) and occasionally congestive heart failure. Anthracyclines and HER2 monoclonal antibodies are common offenders, but clinical practice data on LVEF changes, risk factors and acute recovery is lacking. We retrospectively examined the electronic medical record at an academic medical center for receipt of anthracyclines and/or trastuzumab from 2000 to 2013 in cancer patients. Patient characteristics and serial LVEF assessments were collected. Patients with and without LVEF decline were analyzed by univariate and multivariate analysis. A total of 549 patients were identified with anthracycline/trastuzumab use and 216 had multiple LVEF assessments. Only 27 of the 216 patients who had multiple LVEF assessments at multiple occasions suffered a clinically significant LVEF fall (12.5 %), and symptomatic CHF was rare (0.5 %). Compared to unaffected patients, those with a fall in LVEF were more likely to have hypertension, hyperlipidemia or coronary artery disease (CAD). Concomitant trastuzumab and anthracycline use was a risk factor (36 vs 9.5 % for anthracycline alone, p < 0.001). The median time from start of chemotherapy to reduced LVEF was 202 days (5-3008). On multivariate analysis, hypertension and use of trastuzumab remained independent predictors of LVEF fall. Acute recovery in LVEF was observed in 44 % of patients. LVEF changes from cancer therapies are frequent and hard to predict. Hypertension, hyperlipidemia and CAD are associated with LVEF decline. Acute recovery of LVEF is observed in those experiencing treatment-related cardiotoxicity. Attention to timely interruption of cardiotoxic chemo is recommended.
View details for DOI 10.1007/s12032-016-0797-x
View details for Web of Science ID 000379033100023
View details for PubMedID 27334792
View details for PubMedCentralID PMC5253226
Accelerated two-dimensional cine DENSE cardiovascular magnetic resonance using compressed sensing and parallel imaging
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2016; 18: 38
Cine Displacement Encoding with Stimulated Echoes (DENSE) provides accurate quantitative imaging of cardiac mechanics with rapid displacement and strain analysis; however, image acquisition times are relatively long. Compressed sensing (CS) with parallel imaging (PI) can generally provide high-quality images recovered from data sampled below the Nyquist rate. The purposes of the present study were to develop CS-PI-accelerated acquisition and reconstruction methods for cine DENSE, to assess their accuracy for cardiac imaging using retrospective undersampling, and to demonstrate their feasibility for prospectively-accelerated 2D cine DENSE imaging in a single breathhold.An accelerated cine DENSE sequence with variable-density spiral k-space sampling and golden angle rotations through time was implemented. A CS method, Block LOw-rank Sparsity with Motion-guidance (BLOSM), was combined with sensitivity encoding (SENSE) for the reconstruction of under-sampled multi-coil spiral data. Seven healthy volunteers and 7 patients underwent 2D cine DENSE imaging with fully-sampled acquisitions (14-26 heartbeats in duration) and with prospectively rate-2 and rate-4 accelerated acquisitions (14 and 8 heartbeats in duration). Retrospectively- and prospectively-accelerated data were reconstructed using BLOSM-SENSE and SENSE. Image quality of retrospectively-undersampled data was quantified using the relative root mean square error (rRMSE). Myocardial displacement and circumferential strain were computed for functional assessment, and linear correlation and Bland-Altman analyses were used to compare accelerated acquisitions to fully-sampled reference datasets.For retrospectively-undersampled data, BLOSM-SENSE provided similar or lower rRMSE at rate-2 and lower rRMSE at rate-4 acceleration compared to SENSE (p < 0.05, ANOVA). Similarly, for retrospective undersampling, BLOSM-SENSE provided similar or better correlation with reference displacement and strain data at rate-2 and better correlation at rate-4 acceleration compared to SENSE. Bland-Altman analyses showed similar or better agreement for displacement and strain data at rate-2 and better agreement at rate-4 using BLOSM-SENSE compared to SENSE for retrospectively-undersampled data. Rate-2 and rate-4 prospectively-accelerated cine DENSE provided good image quality and expected values of displacement and strain.BLOSM-SENSE-accelerated spiral cine DENSE imaging with 2D displacement encoding can be acquired in a single breathhold of 8-14 heartbeats with high image quality and accurate assessment of myocardial displacement and circumferential strain.
View details for DOI 10.1186/s12968-016-0253-2
View details for Web of Science ID 000379549800001
View details for PubMedID 27301487
View details for PubMedCentralID PMC4906684
- Myocardial Extracellular Volume Unifying Form and Function in Heart Failure With Preserved Ejection Fraction JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 2016; 67 (15): 1826-1828
Non-Cartesian Balanced Steady-State Free Precession Pulse Sequences for Real-Time Cardiac MRI
MAGNETIC RESONANCE IN MEDICINE
2016; 75 (4): 1546-1555
To develop a new spiral-in/out balanced steady-state free precession (bSSFP) pulse sequence for real-time cardiac MRI and compare it with radial and spiral-out techniques.Non-Cartesian sampling strategies are efficient and robust to motion and thus have important advantages for real-time bSSFP cine imaging. This study describes a new symmetric spiral-in/out sequence with intrinsic gradient moment compensation and SSFP refocusing at TE = TR/2. In vivo real-time cardiac imaging studies were performed to compare radial, spiral-out, and spiral-in/out bSSFP pulse sequences. Furthermore, phase-based fat/water separation taking advantage of the refocusing mechanism of the spiral-in/out bSSFP sequence was also studied.The image quality of the spiral-out and spiral-in/out bSSFP sequences was improved with off-resonance and k-space trajectory correction. The spiral-in/out bSSFP sequence had the highest signal-to-noise ratio (SNR), contrast-to-noise ratio, and image quality ratings, with spiral-out bSSFP sequence second in each category and the radial bSSFP sequence third. The spiral-in/out bSSFP sequence provides separated fat and water images with no additional scan time.In this study, a new spiral-in/out bSSFP sequence was developed and tested. The superiority of spiral bSSFP sequences over the radial bSSFP sequence in terms of SNR and reduced artifacts was demonstrated in real-time MRI of cardiac function without image acceleration.
View details for DOI 10.1002/mrm.25738
View details for Web of Science ID 000372910900015
View details for PubMedID 25960254
View details for PubMedCentralID PMC4637255
T1 Mapping Basic Techniques and Clinical Applications
2016; 9 (1): 67-81
In cardiac magnetic resonance (CMR) imaging, the T1 relaxation time for the 1H magnetization in myocardial tissue may represent a valuable biomarker for a variety of pathological conditions. This possibility has driven the growing interest in quantifying T1, rather than just relying on its effect on image contrast. The techniques have advanced to where pixel-level myocardial T1 mapping has become a routine component of CMR examinations. Combined with the use of contrast agents, T1 mapping has led an expansive investigation of interstitial remodeling in ischemic and nonischemic heart disease. The purpose of this review was to introduce the reader to the physical principles of T1 mapping, the imaging techniques developed for T1 mapping, the pathophysiological markers accessible by T1 mapping, and its clinical uses.
View details for DOI 10.1016/j.jcmg.2015.11.005
View details for Web of Science ID 000368470600011
View details for PubMedID 26762877
Effectiveness of integrating delayed computed tomography angiography imaging for left atrial appendage thrombus exclusion into the care of patients undergoing ablation of atrial fibrillation
2016; 13 (1): 12-19
Computed tomography angiography (CTA) can identify and rule out left atrial appendage (LAA) thrombus when delayed imaging is also performed.In patients referred for CTA to evaluate pulmonary vein anatomy before the ablation of atrial fibrillation (AF) or left atrial flutter (LAFL), we sought to determine the effectiveness of a novel clinical protocol for integrating results of CTA delayed LAA imaging into preprocedure care.After making delayed imaging of the LAA part of our routine preablation CTA protocol, we integrated early reporting of preablation CTA LAA imaging results into clinical practice as part of a formal protocol in June 2013. We then analyzed the effectiveness of this protocol by evaluating 320 AF/LAFL ablation patients with CTA imaging during the time period 2012-2014.In CTA patients with delayed LAA imaging, the sensitivity and negative predictive values for LAA thrombus using intracardiac echocardiography or transesophageal echocardiography (TEE) as the reference standard were both 100%. Intracardiac echocardiography during ablation confirmed the absence of thrombus in patients with negative CTA or negative TEE results. No patients with either negative CTA results or equivocal CTA results combined with negative TEE results had strokes or transient ischemic attacks. Overall, the need for TEE procedures decreased from 57.5% to 24.0% during the 3-year period because of the CTA protocol.Clinical integration of CTA delayed LAA imaging into the care of patients having catheter ablation of AF or LAFL is feasible, safe, and effective. Such a protocol could be used broadly to improve patient care.
View details for DOI 10.1016/j.hrthm.2015.09.002
View details for Web of Science ID 000367394200008
View details for PubMedID 26341605
View details for PubMedCentralID PMC4858349
Detection of elevated right ventricular extracellular volume in pulmonary hypertension using Accelerated and Navigator-Gated Look-Locker Imaging for Cardiac T1 Estimation (ANGIE) cardiovascular magnetic resonance
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2015; 17: 110
Assessment of diffuse right ventricular (RV) fibrosis is of particular interest in pulmonary hypertension (PH) and heart failure (HF). Current cardiovascular magnetic resonance (CMR) T1 mapping techniques such as Modified Look-Locker inversion recovery (MOLLI) imaging have limited resolution, but accelerated and navigator-gated Look-Locker imaging for cardiac T1 estimation (ANGIE) is a novel CMR sequence with spatial resolution suitable for T1 mapping of the RV. We tested the hypothesis that patients with PH would have significantly more RV fibrosis detected with MRI ANGIE compared with normal volunteers and patients having HF with reduced (LV) ejection fraction (HFrEF) without co-existing PH, independent of RV dilitation and dysfunction.Patients with World Health Organization group 1 or group 4 PH, patients with HFrEF without PH, and normal volunteers were recruited to undergo contrast-enhanced CMR. RV and LV extracellular volume fractions (RV-ECV and LV-ECV) were determined using pre-contrast and post-contrast T1 mapping using ANGIE (RV and LV) and MOLLI (LV only).Thirty-two participants (53.1% female, median age 52 years, IQR 26-65 years) were enrolled, including n = 12 with PH, n = 10 having HFrEF without co-existing PH, and n = 10 normal volunteers. ANGIE ECV imaging was of high quality, and ANGIE measurements of LV-ECV were highly correlated with those of MOLLI (r = 0.91; p < 0.001). The RV-ECV in PH patients was 27.2% greater than the RV-ECV in normal volunteers (0.341 v. 0.268; p < 0.0001) and 18.9% greater than the RV-ECV in HFrEF patients without PH (0.341 v. 0.287; p < 0.0001). RV-ECV was greater than LV-ECV in PH (RV-LV difference = 0.04), but RV-ECV was nearly equivalent to LV-ECV in normal volunteers (RV-LV difference = 0.002) (p < 0.0001 for RV-LV difference in PH versus normal volunteers). RV-ECV was linearly associated with both increasing RVEDVI (p = 0.049) and decreasing RVEF (p = 0.04) in a multivariable linear model, but PH was still associated with greater RV-ECV even after adjustment for RVEDVI and RVEF.Pre- and post-contrast ANGIE imaging provides high-resolution ECV determination for the RV. PH is independently associated with increased RV-ECV even after adjustment for RV dilatation and dysfunction, consistent with an independent effect of PH on fibrosis. ANGIE RV imaging merits further clinical evaluation in PH.
View details for DOI 10.1186/s12968-015-0209-y
View details for Web of Science ID 000366795500001
View details for PubMedID 26692265
View details for PubMedCentralID PMC4687111
Meta-Analysis of Diagnostic Performance of Coronary Computed Tomography Angiography, Computed Tomography Perfusion, and Computed Tomography-Fractional Flow Reserve in Functional Myocardial Ischemia Assessment Versus Invasive Fractional Flow Reserve
AMERICAN JOURNAL OF CARDIOLOGY
2015; 116 (9): 1469-1478
We sought to compare the diagnostic performance of coronary computed tomography angiography (CCTA), computed tomography perfusion (CTP), and computed tomography (CT)-fractional flow reserve (FFR) for assessing the functional significance of coronary stenosis as defined by invasive FFR in patients with known or suspected coronary artery disease (CAD). CCTA has proved clinically useful for excluding obstructive CAD because of its high sensitivity and negative predictive value (NPV); however, the ability of CTA to identify functionally significant CAD has remained challenging. We searched PubMed/Medline for studies evaluating CCTA, CTP, or CT-FFR for the noninvasive detection of obstructive CAD compared with catheter-derived FFR as the reference standard. Pooled sensitivity, specificity, PPV, NPV, likelihood ratios, and odds ratio of all diagnostic tests were assessed. Eighteen studies involving a total of 1,535 patients were included. CTA demonstrated a pooled sensitivity of 0.92, specificity 0.43, PPV of 0.56, and NPV of 0.87 on a per-patient level. CT-FFR and CTP increased the specificity to 0.72 and 0.77, respectively (p = 0.004 and p = 0.0009) resulting in higher point estimates for PPV 0.70 and 0.83, respectively. There was no improvement in the sensitivity. The CTP protocol involved more radiation (3.5 mSv CCTA vs 9.6 mSv CTP) and a higher volume of iodinated contrast (145 ml). In conclusion, CTP and CT-FFR improve the specificity of CCTA for detecting functionally significant stenosis as defined by invasive FFR on a per-patient level; both techniques could advance the ability to noninvasively detect the functional significance of coronary lesions.
View details for DOI 10.1016/j.amjcard.2015.07.078
View details for Web of Science ID 000364621400026
View details for PubMedID 26347004
View details for PubMedCentralID PMC4851492
Saturation pulse design for quantitative myocardial T-1 mapping
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2015; 17: 84
Quantitative saturation-recovery based T1 mapping sequences are less sensitive to systematic errors than the Modified Look-Locker Inversion recovery (MOLLI) technique but require high performance saturation pulses. We propose to optimize adiabatic and pulse train saturation pulses for quantitative T1 mapping to have <1 % absolute residual longitudinal magnetization (|MZ/M0|) over ranges of B0 and [Formula: see text] (B1 scale factor) inhomogeneity found at 1.5 T and 3 T.Design parameters for an adiabatic BIR4-90 pulse were optimized for improved performance within 1.5 T B0 (±120 Hz) and [Formula: see text] (0.7-1.0) ranges. Flip angles in hard pulse trains of 3-6 pulses were optimized for 1.5 T and 3 T, with consideration of T1 values, field inhomogeneities (B0 = ±240 Hz and [Formula: see text]=0.4-1.2 at 3 T), and maximum achievable B1 field strength. Residual MZ/M0 was simulated and measured experimentally for current standard and optimized saturation pulses in phantoms and in-vivo human studies. T1 maps were acquired at 3 T in human subjects and a swine using a SAturation recovery single-SHot Acquisition (SASHA) technique with a standard 90°-90°-90° and an optimized 6-pulse train.Measured residual MZ/M0 in phantoms had excellent agreement with simulations over a wide range of B0 and [Formula: see text]. The optimized BIR4-90 reduced the maximum residual |MZ/M0| to <1 %, a 5.8× reduction compared to a reference BIR4-90. An optimized 3-pulse train achieved a maximum residual |MZ/M0| <1 % for the 1.5 T optimization range compared to 11.3 % for a standard 90°-90°-90° pulse train, while a 6-pulse train met this target for the wider 3 T ranges of B0 and [Formula: see text]. The 6-pulse train demonstrated more uniform saturation across both the myocardium and entire field of view than other saturation pulses in human studies. T1 maps were more spatially homogeneous with 6-pulse train SASHA than the reference 90°-90°-90° SASHA in both human and animal studies.Adiabatic and pulse train saturation pulses optimized for different constraints found at 1.5 T and 3 T achieved <1 % residual |MZ/M0| in phantom experiments, enabling greater accuracy in quantitative saturation recovery T1 imaging.
View details for DOI 10.1186/s12968-015-0187-0
View details for Web of Science ID 000362163700001
View details for PubMedID 26428468
View details for PubMedCentralID PMC4589956
Influence of phase correction of late gadolinium enhancement images on scar signal quantification in patients with ischemic and non-ischemic cardiomyopathy
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2015; 17: 66
Myocardial fibrosis imaging using late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) has been validated as a quantitative predictive marker for response to medical, surgical, and device therapy. To date, all such studies have examined conventional, non-phase corrected magnitude images. However, contemporary practice has rapdily adopted phase-corrected image reconstruction. We sought to investigate the existence of any systematic bias between threshold-based scar quantification performed on conventional magnitude inversion recovery (MIR) and matched phase sensitive inversion recovery (PSIR) images.In 80 patients with confirmed ischemic (N = 40), or non-ischemic (n = 40) myocardial fibrosis, and also in a healthy control cohort (N = 40) without fibrosis, myocardial late enhancement was quantified using a Signal Threshold Versus Reference Myocardium technique (STRM) at ≥2, ≥3, and ≥5 SD threshold, and also using the Full Width at Half Maximal (FWHM) technique. This was performed on both MIR and PSIR images and values compared using linear regression and Bland-Altman analyses.Linear regression analysis demonstrated excellent correlation for scar volumes between MIR and PSIR images at all three STRM signal thresholds for the ischemic (N = 40, r = 0.96, 0.95, 0.88 at 2, 3, and 5 SD, p < 0.0001 for all regressions), and non ischemic (N = 40, r = 0.86, 0.89, 0.90 at 2, 3, and 5 SD, p < 0.0001 for all regressions) cohorts. FWHM analysis demonstrated good correlation in the ischemic population (N = 40, r = 0.83, p < 0.0001). Bland-Altman analysis demonstrated a systematic bias with MIR images showing higher values than PSIR for ischemic (3.3 %, 3.9 % and 4.9 % at 2, 3, and 5 SD, respectively), and non-ischemic (9.7 %, 7.4 % and 4.1 % at ≥2, ≥3, and ≥5 SD thresholds, respectively) cohorts. Background myocardial signal measured in the control population demonstrated a similar bias of 4.4 %, 2.6 % and 0.7 % of the LV volume at 2, 3 and 5 SD thresholds, respectively. The bias observed using FWHM analysis was -6.9 %.Scar quantification using phase corrected (PSIR) images achieves values highly correlated to those obtained on non-corrected (MIR) images. However, a systematic bias exists that appears exaggerated in non-ischemic cohorts. Such bias should be considered when comparing or translating knowledge between MIR- and PSIR-based imaging.
View details for DOI 10.1186/s12968-015-0163-8
View details for Web of Science ID 000359042600001
View details for PubMedID 26248535
View details for PubMedCentralID PMC4528363
- REPLY: : Extracellular Volume and Cardiac Mechanics: Have We Found a Missing Puzzle Piece? JACC-CARDIOVASCULAR IMAGING 2015; 8 (6): 749
Increased Extracellular Volume and Altered Mechanics Are Associated With LVH in Hypertensive Heart Disease, Not Hypertension Alone
2015; 8 (2): 172-180
The goal of this study was to assess the relationship among extracellular volume (ECV), native T1, and systolic strain in hypertensive patients with left ventricular hypertrophy (HTN LVH), hypertensive patients without LVH (HTN non-LVH), and normotensive controls.Diffuse myocardial fibrosis in HTN LVH patients, as reflected by increased ECV and native T1, may be an underlying mechanism contributing to increased cardiovascular risk compared with HTN non-LVH subjects and controls. Furthermore, increased diffuse fibrosis in HTN LVH subjects may be associated with reduced peak systolic and early diastolic strain rate compared with the other 2 groups.T1 mapping was performed in 20 HTN LVH (mean age, 55 ± 11 years), 23 HTN non-LVH (mean age, 61 ± 12 years), and 22 control subjects (mean age, 54 ± 7 years) on a Siemens 1.5-T Avanto (Siemens Healthcare, Erlangen, Germany) using a previously validated modified look-locker inversion-recovery pulse sequence. T1 was measured pre-contrast and 10, 15, and 20 min after injection of 0.15 mmol/kg gadopentetate dimeglumine, and the mean ECV and native T1 were determined for each subject. Measurement of circumferential strain parameters were performed using cine displacement encoding with stimulated echoes.HTN LVH subjects had higher native T1 compared with controls (p < 0.05). HTN LVH subjects had higher ECV compared with HTN non-LVH subjects and controls (p < 0.05). Peak systolic circumferential strain and early diastolic strain rates were reduced in HTN LVH subjects compared with HTN non-LVH subjects and controls (p < 0.05). Increased levels of ECV and native T1 were associated with reduced peak systolic and early diastolic circumferential strain rate across all subjects.HTN LVH patients had higher ECV, longer native T1 and associated reduction in peak systolic circumferential strain, and early diastolic strain rate compared with HTN non-LVH and control subjects. Measurement of ECV and native T1 provide a noninvasive assessment of diffuse fibrosis in hypertensive heart disease.
View details for DOI 10.1016/j.jcmg.2014.09.020
View details for Web of Science ID 000349659400009
View details for PubMedID 25577446
View details for PubMedCentralID PMC4418794
- Advanced Normalization Tools for Cardiac Motion Correction SPRINGER-VERLAG BERLIN. 2015: 3-12
Accelerated and Navigator-Gated Look-Locker Imaging for Cardiac T1 Estimation (ANGIE): Development and Application to T1 Mapping of the Right Ventricle
MAGNETIC RESONANCE IN MEDICINE
2015; 73 (1): 150-160
To develop a method for high-resolution cardiac T1 mapping.A new method, accelerated and navigator-gated look-locker imaging for cardiac T1 estimation (ANGIE), was developed. An adaptive acquisition algorithm that accounts for the interplay between navigator gating and undersampling patterns well-suited for compressed sensing was used to minimize scan time. Computer simulations, phantom experiments, and imaging of the left ventricle (LV) were used to optimize and evaluate ANGIE. ANGIE's high spatial resolution was demonstrated by T1 mapping of the right ventricle (RV). Comparisons were made to modified Look-Locker imaging (MOLLI).Retrospective reconstruction of fully sampled datasets demonstrated the advantages of the adaptive algorithm. For the LV, ANGIE measurements of T1 were in good agreement with MOLLI. For the RV, ANGIE achieved a spatial resolution of 1.2 × 1.2 mm(2) with a scan time of 157 ± 53 s per slice, and measured RV T1 values of 980 ± 96 ms versus 1076 ± 157 ms for lower-resolution MOLLI. ANGIE provided lower intrascan variation in the RV T1 estimate compared with MOLLI (P < 0.05).ANGIE enables high-resolution cardiac T1 mapping in clinically reasonable scan times. ANGIE opens the prospect of quantitative T1 mapping of thin cardiovascular structures such as the RV wall.
View details for DOI 10.1002/mrm.25100
View details for Web of Science ID 000346908800014
View details for PubMedID 24515952
View details for PubMedCentralID PMC4128906
Motion-Compensated Compressed Sensing for Dynamic Contrast-Enhanced MRI Using Regional Spatiotemporal Sparsity and Region Tracking: Block LOw-rank Sparsity with Motion-guidance (BLOSM)
MAGNETIC RESONANCE IN MEDICINE
2014; 72 (4): 1028-1038
Dynamic contrast-enhanced MRI of the heart is well-suited for acceleration with compressed sensing (CS) due to its spatiotemporal sparsity; however, respiratory motion can degrade sparsity and lead to image artifacts. We sought to develop a motion-compensated CS method for this application.A new method, Block LOw-rank Sparsity with Motion-guidance (BLOSM), was developed to accelerate first-pass cardiac MRI, even in the presence of respiratory motion. This method divides the images into regions, tracks the regions through time, and applies matrix low-rank sparsity to the tracked regions. BLOSM was evaluated using computer simulations and first-pass cardiac datasets from human subjects. Using rate-4 undersampling, BLOSM was compared with other CS methods such as k-t SLR that uses matrix low-rank sparsity applied to the whole image dataset, with and without motion tracking, and to k-t FOCUSS with motion estimation and compensation that uses spatial and temporal-frequency sparsity.BLOSM was qualitatively shown to reduce respiratory artifact compared with other methods. Quantitatively, using root mean squared error and the structural similarity index, BLOSM was superior to other methods.BLOSM, which exploits regional low-rank structure and uses region tracking for motion compensation, provides improved image quality for CS-accelerated first-pass cardiac MRI.
View details for DOI 10.1002/mrm.25018
View details for Web of Science ID 000342342300014
View details for PubMedID 24243528
View details for PubMedCentralID PMC4097987
- Seeing the Unseen Fibrosis in Heart Failure With Preserved Ejection Fraction JACC-CARDIOVASCULAR IMAGING 2014; 7 (10): 998-1000
Effect of Microvascular Obstruction and Intramyocardial Hemorrhage by CMR on LV Remodeling and Outcomes After Myocardial Infarction A Systematic Review and Meta-Analysis
2014; 7 (9): 940-952
The goal of this systematic analysis is to provide a comprehensive review of the current cardiac magnetic resonance data on microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH). Data related to the association of MVO and IMH in patients with acute myocardial infarction (MI) with left ventricular (LV) function, volumes, adverse LV remodeling, and major adverse cardiac events (MACE) were critically analyzed. MVO is associated with a lower ejection fraction, increased ventricular volumes and infarct size, and a greater risk of MACE. Late MVO is shown to be a stronger prognostic marker for MACE and cardiac death, recurrent MI, congestive heart failure/heart failure hospitalization, and follow-up LV end-systolic volumes than early MVO. IMH is associated with LV remodeling and MACE on pooled analysis, but because of limited data and heterogeneity in study methodology, the effects of IMH on remodeling require further investigation.
View details for DOI 10.1016/j.jcmg.2014.06.012
View details for Web of Science ID 000342268100014
View details for PubMedID 25212800
View details for PubMedCentralID PMC4301583
Adenosine Stress Cardiovascular Magnetic Resonance With Variable-Density Spiral Pulse Sequences Accurately Detects Coronary Artery Disease Initial Clinical Evaluation
2014; 7 (4): 639-U109
Adenosine stress cardiovascular magnetic resonance perfusion imaging can be limited by motion-induced dark-rim artifacts, which may be mistaken for true perfusion abnormalities. A high-resolution variable-density spiral pulse sequence with a novel density compensation strategy has been shown to reduce dark-rim artifacts in first-pass perfusion imaging. We aimed to assess the clinical performance of adenosine stress cardiovascular magnetic resonance using this new perfusion sequence to detect obstructive coronary artery disease.Cardiovascular magnetic resonance perfusion imaging was performed during adenosine stress (140 μg/kg per minute) and at rest on a Siemens 1.5-T Avanto scanner in 41 subjects with chest pain scheduled for coronary angiography. Perfusion images were acquired during injection of 0.1 mmol/kg Gadolinium-diethylenetriaminepentacetate at 3 short-axis locations using a saturation recovery interleaved variable-density spiral pulse sequence. Significant stenosis was defined as >50% by quantitative coronary angiography. Two blinded reviewers evaluated the perfusion images for the presence of adenosine-induced perfusion abnormalities and assessed image quality using a 5-point scale (1 [poor] to 5 [excellent]). The prevalence of obstructive coronary artery disease by quantitative coronary angiography was 68%. The average sensitivity, specificity, and accuracy were 89%, 85%, and 88%, respectively, with a positive predictive value and negative predictive value of 93% and 79%, respectively. The average image quality score was 4.4±0.7, with only 1 study with more than mild dark-rim artifacts. There was good inter-reader reliability with a κ statistic of 0.67.Spiral adenosine stress cardiovascular magnetic resonance results in high diagnostic accuracy for the detection of obstructive coronary artery disease with excellent image quality and minimal dark-rim artifacts.
View details for DOI 10.1161/CIRCIMAGING.113.001584
View details for Web of Science ID 000339172100010
View details for PubMedID 24759900
View details for PubMedCentralID PMC4102611
Postprocedure Mapping of Cardiac Resynchronization Lead Position Using Standard Fluoroscopy Systems: Implications for the Nonresponder with Scar
PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY
2014; 37 (6): 757-767
The relationship between cardiac resynchronization therapy (CRT), left ventricular (LV) lead position, scar, and regional mechanical function influences CRT response.To determine LV lead position relative to LV structural characteristics in standard clinical practice, we developed and validated a practical yet mathematically rigorous method to register procedural fluoroscopic LV lead position with pre-CRT cardiac magnetic resonance (CMR).After one-time calibration of the standard fluoroscopic suite, we identified the projected CMR LV lead position using three reference landmarks on both CMR and fluoroscopy. This predicted lead position was validated in a canine model by histology and in eight "validation group" patients based on postoperative computed tomography scans (n = 7) or CMR coronary sinus venography (n = 1). The methodology was applied in an additional eight patients with CRT nonresponse and infarction-related myocardial scar.The projected and actual lead positions were within 1.2 mm in the canine model. The median distance between projected and actual lead positions for the validation group (n = 8) and animal validation case was 11.3 mm (interquartile range 9.2-14.6 mm). In the application (nonresponder) group (n = 8), the lead mapped to the scar periphery in three patients, the core of the scar in one patient, and more than 3 cm from scar in four patients.This methodology projects procedural fluoroscopic LV lead position onto pre-CRT CMR using standard fluoroscopic equipment and a one-time calibration, enabling assessment of LV lead position with sufficient accuracy to identify the lead position relative to regional function and infarction-related scar in CRT nonresponders.
View details for DOI 10.1111/pace.12344
View details for Web of Science ID 000337733100015
View details for PubMedID 24472061
View details for PubMedCentralID PMC4055519
Impact of Mechanical Activation, Scar, and Electrical Timing on Cardiac Resynchronization Therapy Response and Clinical Outcomes
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2014; 63 (16): 1657-1666
Using cardiac magnetic resonance (CMR), we sought to evaluate the relative influences of mechanical, electrical, and scar properties at the left ventricular lead position (LVLP) on cardiac resynchronization therapy (CRT) response and clinical events.CMR cine displacement encoding with stimulated echoes (DENSE) provides high-quality strain for overall dyssynchrony (circumferential uniformity ratio estimate [CURE] 0 to 1) and timing of onset of circumferential contraction at the LVLP. CMR DENSE, late gadolinium enhancement, and electrical timing together could improve upon other imaging modalities for evaluating the optimal LVLP.Patients had complete CMR studies and echocardiography before CRT. CRT response was defined as a 15% reduction in left ventricular end-systolic volume. Electrical activation was assessed as the time from QRS onset to LVLP electrogram (QLV). Patients were then followed for clinical events.In 75 patients, multivariable logistic modeling accurately identified the 40 patients (53%) with CRT response (area under the curve: 0.95 [p < 0.0001]) based on CURE (odds ratio [OR]: 2.59/0.1 decrease), delayed circumferential contraction onset at LVLP (OR: 6.55), absent LVLP scar (OR: 14.9), and QLV (OR: 1.31/10 ms increase). The 33% of patients with CURE <0.70, absence of LVLP scar, and delayed LVLP contraction onset had a 100% response rate, whereas those with CURE ≥0.70 had a 0% CRT response rate and a 12-fold increased risk of death; the remaining patients had a mixed response profile.Mechanical, electrical, and scar properties at the LVLP together with CMR mechanical dyssynchrony are strongly associated with echocardiographic CRT response and clinical events after CRT. Modeling these findings holds promise for improving CRT outcomes.
View details for DOI 10.1016/j.jacc.2014.02.533
View details for Web of Science ID 000334736300011
View details for PubMedID 24583155
View details for PubMedCentralID PMC4427624
Late Gadolinium Enhancement on Cardiac Magnetic Resonance Predicts Adverse Cardiovascular Outcomes in Nonischemic Cardiomyopathy A Systematic Review and Meta-Analysis
2014; 7 (2): 250-258
Late gadolinium enhancement (LGE) by cardiac MR (CMR) is a predictor of adverse cardiovascular outcomes in patients with nonischemic cardiomyopathy (NICM). However, these findings are limited by single-center studies, small sample sizes, and low event rates. We performed a meta-analysis to evaluate the prognostic role of LGE by CMR (LGE-CMR) imaging in patients with NICM.PubMed, Cochrane CENTRAL, and EMBASE were searched for studies looking at the prognostic value of LGE-CMR in patients with NICM. The primary end points included all-cause mortality, heart failure hospitalization, and a composite end point of sudden cardiac death (SCD) or aborted SCD. Pooling of odds ratios was performed using a random-effect model, and annualized event rates were assessed. Data were included from 9 studies with a total of 1488 patients and a mean follow-up of 30 months. Patients had a mean age of 52 years, 67% were men, and the average left ventricular ejection fraction was 37% on CMR. LGE was present in 38% of patients. Patients with LGE had increased overall mortality (odds ratio, 3.27; P<0.00001), heart failure hospitalization (odds ratio, 2.91; P=0.02), and SCD/aborted SCD (odds ratio, 5.32; P<0.00001) compared with those without LGE. The annualized event rates for mortality were 4.7% for LGE+ subjects versus 1.7% for LGE- subjects (P=0.01), 5.03% versus 1.8% for heart failure hospitalization (P=0.002), and 6.0% versus 1.2% for SCD/aborted SCD (P<0.001).LGE in patients with NICM is associated with increased risk of all-cause mortality, heart failure hospitalization, and SCD. Detection of LGE by CMR has excellent prognostic characteristics and may help guide risk stratification and management in patients with NICM.
View details for DOI 10.1161/CIRCIMAGING.113.001144
View details for Web of Science ID 000332994400006
View details for PubMedID 24363358
View details for PubMedCentralID PMC4007583
PET/MRI: Current state of the art and future potential for cardiovascular applications
JOURNAL OF NUCLEAR CARDIOLOGY
2013; 20 (6): 976-989
Positron emission tomography-magnetic resonance imaging (PET/MRI) is emerging as a novel diagnostic modality with exciting potential for a role in multiple cardiovascular applications. The combination of the high sensitivity of PET tracers with the excellent spatial resolution and tissue characterization of cardiac MRI will provide complementary information in a variety of cardiac pathologies. While initial efforts have focused on the combination of MRI and PET for assessment of coronary artery disease, cardiomyopathy, viability, and inflammation, this new technology holds enormous potential for molecular cardiovascular imaging. This article will review the development of PET/MRI, review the current research, and discuss potential future applications.
View details for DOI 10.1007/s12350-013-9780-5
View details for Web of Science ID 000327858600006
View details for PubMedID 23996656
Markedly Increased Volume of Distribution of Gadolinium in Cardiac Amyloidosis Demonstrated by T-1 Mapping
JOURNAL OF MAGNETIC RESONANCE IMAGING
2013; 38 (6): 1591-1595
To perform myocardial T1 mapping pre- and post-gadolinium (Gd) administration and determine the volume of distribution of Gd (VdGd ) in patients with cardiac amyloidosis to assess extracellular space expansion from amyloid protein deposition.T1 mapping was performed before contrast and 20 minutes following bolus administration of 0.15 mmol/kg of gadopentetate dimeglumine (Magnevist) in five subjects with cardiac amyloidosis and in eight healthy volunteers using previously validated 3-5 Modified Look-Locker Inversion (MOLLI) pulse sequence. The partition coefficient (λ) and VdGd were determined and compared between groups.Before contrast the T1 of the blood and myocardium are longer in amyloidosis as compared to controls (1665 vs. 1509 msec; P = 0.03 and 1144 vs. 963 msec; P < 0.001, respectively). Postcontrast blood T1 was also significantly longer in amyloidosis (486 vs. 408 msec; P = 0.003) with a trend towards shorter T1 in the myocardium (503 vs. 544 msec; P = 0.15). The VdGd was 83% higher in amyloidosis than in controls (0.51 vs. 0.28; P = 0.005).Myocardial VdGd is markedly increased in cardiac amyloidosis, reflecting the increased extracellular space occupied by amyloid proteins. The precontrast T1 of blood and myocardium are increased in amyloidosis extending diagnostic utility in patients who cannot receive Gd.
View details for DOI 10.1002/jmri.24078
View details for Web of Science ID 000327756800035
View details for PubMedID 23450747
View details for PubMedCentralID PMC3855558
Electromechanical and Scar-Mediated Interactions in Cardiac Resynchronization Therapy Based on Cardiac Magnetic Resonance
LIPPINCOTT WILLIAMS & WILKINS. 2013
View details for Web of Science ID 000332162907542
MRI T1 Mapping of the Right Ventricle Using High Resolution ANGIE
LIPPINCOTT WILLIAMS & WILKINS. 2013
View details for Web of Science ID 000332162902005
Quantifying Myocardial Fibrosis in Hypertensive Left Ventricular Hypertrophy Using T1 Mapping
LIPPINCOTT WILLIAMS & WILKINS. 2013
View details for Web of Science ID 000332162902103
Improved First-Pass Spiral Myocardial Perfusion Imaging with Variable Density Trajectories
MAGNETIC RESONANCE IN MEDICINE
2013; 70 (5): 1369-1379
To develop and evaluate variable-density spiral first-pass perfusion pulse sequences for improved efficiency and off-resonance performance and to demonstrate the utility of an apodizing density compensation function (DCF) to improve signal-to-noise ratio (SNR) and reduce dark-rim artifact caused by cardiac motion and Gibbs Ringing.Three variable density spiral trajectories were designed, simulated, and evaluated in 18 normal subjects, and in eight patients with cardiac pathology on a 1.5T scanner.By using a DCF, which intentionally apodizes the k-space data, the sidelobe amplitude of the theoretical point spread function (PSF) is reduced by 68%, with only a 13% increase in the full-width at half-maximum of the main-lobe when compared with the same data corrected with a conventional variable-density DCF, and has an 8% higher resolution than a uniform density spiral with the same number of interleaves and readout duration. Furthermore, this strategy results in a greater than 60% increase in measured SNR when compared with the same variable-density spiral data corrected with a conventional DCF (P < 0.01). Perfusion defects could be clearly visualized with minimal off-resonance and dark-rim artifacts.Variable-density spiral pulse sequences using an apodized DCF produce high-quality first-pass perfusion images with minimal dark-rim and off-resonance artifacts, high SNR and contrast-to-noise ratio, and good delineation of resting perfusion abnormalities.
View details for DOI 10.1002/mrm.24569
View details for Web of Science ID 000326115000020
View details for PubMedID 23280884
View details for PubMedCentralID PMC3929110
Prognostic Value of Stress Cardiac Magnetic Resonance Imaging in Patients With Known or Suspected Coronary Artery Disease A Systematic Review and Meta-Analysis
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2013; 62 (9): 826-838
This study sought to perform a systematic review and meta-analysis to understand the role of stress cardiac magnetic resonance imaging (CMR) in assessing cardiovascular prognosis in patients with known or suspected coronary artery disease (CAD).Although stress CMR is excellent for the diagnosis of obstructive CAD, the prognostic value of stress CMR has been less well described.PubMed, Cochrane CENTRAL, and metaRegister of Controlled Trials were searched for stress CMR studies with >6 months of prognostic data. Primary endpoints were cardiovascular death, myocardial infarction (MI), and a composite outcome of cardiovascular death or MI during follow-up. Summary effect estimates were generated with random-effects modeling, and annualized event rates were assessed.Nineteen studies (14 vasodilator, 4 dobutamine, and 1 that used both) involved a total of 11,636 patients with a mean follow-up of 32 months. Patients had a mean age of 63 ± 12 years, 63% were male, and 26% had previous MI; mean left ventricular ejection fraction was 61 ± 12%; and late gadolinium enhancement was present in 29% and ischemia in 32%. Patients with ischemia had a higher incidence of MI (odds ratio [OR]: 7.7; p < 0.0001), cardiovascular death (OR: 7.0; p < 0.0001), and the combined endpoint (OR: 6.5; p < 0.0001) compared with those with a negative study. The combined outcome annualized events rates were 4.9% for a positive versus 0.8% for a negative stress CMR (p < 0.0001), 2.8% versus 0.3% for cardiovascular death (p < 0.0001), and 2.6% versus 0.4% for MI (p < 0.0005). The presence of late gadolinium enhancement was also significantly associated with a worse prognosis.A negative stress CMR study is associated with very low risk of cardiovascular death and MI. Stress CMR has excellent prognostic characteristics and may help guide risk stratification of patients with known or suspected CAD.
View details for DOI 10.1016/j.jacc.2013.03.080
View details for Web of Science ID 000323899900010
View details for PubMedID 23727209
View details for PubMedCentralID PMC3863376
Prognostic value of late gadolinium enhancement in dilated cardiomyopathy patients A meta-analysis
SAUDI MEDICAL JOURNAL
2013; 34 (7): 719-726
To evaluate the prognostic value of late gadolinium enhancement (LGE) in dilated cardiomyopathy (DCM) patients.We searched PubMed, MEDLINE, the Cochrane library and EMBASE databases from September to December 2012 in the Renmin Hospital of Wuhan University, Wuhan, China for studies of LGE in DCM patients. We extracted the clinical outcomes (all-cause mortality, cardiovascular mortality, sudden cardiac death [SCD], aborted SCD, heart failure hospitalization) after carefully reviewed. A meta-analysis was performed to calculate pooled odds ratios (OR) with 95% confidence intervals (CIs) for prognostic outcomes in LGE positive versus LGE negative patients with DCM.Five studies for 545 DCM patients were contained in this meta-analysis. The results showed LGE positive patients was significantly associated with higher cardiovascular mortality (pooled OR: 2.67; 95% CI: 1.12-6.35; p=0.03), aborted SCD (pooled OR: 5.26; 95% CI: 1.57-17.55; p=0.007), and heart failure hospitalization (pooled OR: 3.91; 95% CI: 1.99-7.69; p<0.001).Late gadolinium enhancement during cardiac MRI is significantly associated with cardiovascular mortality, aborted SCD and heart failure hospitalization in DCM patients. The LGE can be a potential stratification tool to predict the risk of cardiac events among patients with DCM.
View details for Web of Science ID 000327423700009
View details for PubMedID 23860892
Comparison of methods for determining the partition coefficient of gadolinium in the myocardium using T-1 mapping
JOURNAL OF MAGNETIC RESONANCE IMAGING
2013; 38 (1): 217-224
To develop and validate modified Look-Locker (MOLLI) protocols to generate myocardial T1 maps within clinically acceptable breath-hold durations and to compare partition coefficients (λ) of gadolinium (Gd)-DTPA determined from either bolus injection (BI) or continuous infusion (CI) techniques.T1 mapping was performed in phantoms and in 10 volunteers on a 1.5T scanner using the standard (3-3-5) MOLLI technique and two MOLLI schemes with shorter breath-hold durations. Imaging was performed precontrast and every 5 minutes following a bolus of 0.1 mmol/kg Gd-DTPA and a 15-minute delayed continuous infusion of 0.001 mmol/kg Gd-DTPA until equilibrium T1 in the myocardium was achieved to enable direct comparison of T1 relaxation times between techniques and λ's between the BI and CI methods.There was good agreement of T1 values between the 3-3-5 standard MOLLI protocol and the modified 3-5 MOLLI protocol in both phantom studies over a range of heart rates and in human subjects. Both MOLLI protocols produced similar measurements of λ using both the BI and CI methods.A reduced breath-hold MOLLI T1 mapping protocol combined with the BI method can accurately characterize T1 and λ in clinically applicable breath-hold durations without requiring a long equilibrium phase infusion.
View details for DOI 10.1002/jmri.23875
View details for Web of Science ID 000321614600027
View details for PubMedID 23197434
View details for PubMedCentralID PMC3899916
Advances in Parametric Mapping With CMR Imaging
2013; 6 (7): 806-822
Cardiac magnetic resonance imaging (CMR) is well established and considered the gold standard for assessing myocardial volumes and function, and for quantifying myocardial fibrosis in both ischemic and nonischemic heart disease. Recent developments in CMR imaging techniques are enabling clinically-feasible rapid parametric mapping of myocardial perfusion and magnetic relaxation properties (T1, T2, and T2* relaxation times) that are further expanding the range of unique tissue parameters that can be assessed using CMR. To generate a parametric map of perfusion or relaxation times, multiple images of the same region of the myocardium are acquired with different sensitivity to the parameter of interest, and the signal intensities of these images are fit to a model which describes the underlying physiology or relaxation parameters. The parametric map is an image of the fitted perfusion parameters or relaxation times. Parametric mapping requires acquisition of multiple images typically within a breath-hold and thus requires specialized rapid acquisition techniques. Quantitative perfusion imaging techniques can more accurately determine the extent of myocardial ischemia in coronary artery disease and provide the opportunity to evaluate microvascular disease with CMR. T1 mapping techniques performed both with and without contrast are enabling quantification of diffuse myocardial fibrosis and myocardial infiltration. Myocardial edema and inflammation can be evaluated using T2 mapping techniques. T2* mapping provides an assessment of myocardial iron-overload and myocardial hemorrhage. There is a growing body of evidence for the clinical utility of quantitative assessment of perfusion and relaxation times, although current techniques still have some important limitations. This article will review the current imaging technologies for parametric mapping, emerging applications, current limitations, and potential of CMR parametric mapping of the myocardium. The specific focus will be the assessment and quantification of myocardial perfusion and magnetic relaxation times.
View details for DOI 10.1016/j.jcmg.2013.05.005
View details for Web of Science ID 000321677300008
View details for PubMedID 23845576
View details for PubMedCentralID PMC4073213
Kalman filter techniques for accelerated Cartesian dynamic cardiac imaging
MAGNETIC RESONANCE IN MEDICINE
2013; 69 (5): 1346-1356
In dynamic MRI, spatial and temporal parallel imaging can be exploited to reduce scan time. Real-time reconstruction enables immediate visualization during the scan. Commonly used view-sharing techniques suffer from limited temporal resolution, and many of the more advanced reconstruction methods are either retrospective, time-consuming, or both. A Kalman filter model capable of real-time reconstruction can be used to increase the spatial and temporal resolution in dynamic MRI reconstruction. The original study describing the use of the Kalman filter in dynamic MRI was limited to non-Cartesian trajectories because of a limitation intrinsic to the dynamic model used in that study. Here the limitation is overcome, and the model is applied to the more commonly used Cartesian trajectory with fast reconstruction. Furthermore, a combination of the Kalman filter model with Cartesian parallel imaging is presented to further increase the spatial and temporal resolution and signal-to-noise ratio. Simulations and experiments were conducted to demonstrate that the Kalman filter model can increase the temporal resolution of the image series compared with view-sharing techniques and decrease the spatial aliasing compared with TGRAPPA. The method requires relatively little computation, and thus is suitable for real-time reconstruction.
View details for DOI 10.1002/mrm.24375
View details for Web of Science ID 000318026400017
View details for PubMedID 22926804
View details for PubMedCentralID PMC3536913
- PROGNOSTIC VALUE OF STRESS CARDIAC MAGNETIC RESONANCE IMAGING IN PATIENTS WITH KNOWN OR SUSPECTED CORONARY ARTERY DISEASE: A SYSTEMATIC REVIEW AND META-ANALYSIS ELSEVIER SCIENCE INC. 2013: E809
Elevated circulating fibrocyte levels in patients with hypertensive heart disease
JOURNAL OF HYPERTENSION
2012; 30 (9): 1856-1861
Autopsy and biopsy studies have shown that there is significantly more fibrosis in hearts of patients with hypertensive heart disease compared to normal hearts. Fibrocytes, a population of circulating bone marrow-derived cells, have been shown to home to tissues and promote scar formation in several diseases, but their role in human hypertensive heart disease has not been investigated to date. Our objective was to determine whether fibrocyte levels are elevated in individuals with hypertensive heart disease.We measured peripheral blood fibrocyte levels and their activated phenotypes in 12 individuals with hypertensive heart disease as determined by increased left ventricular mass on noninvasive imaging and compared them to fibrocyte levels from 19 healthy normal controls and correlated them to cardiac MRI findings.Compared to normal controls, individuals with hypertensive heart disease had significantly higher circulating levels of total fibrocytes [median (interquartile range); 149000 (62200-220000) vs. 564500 (321000-1.2900e(+006)), P < 0.0001, respectively] as well as activated fibrocytes [15700 (6380-19800) vs. 478500 (116500-1.2360e(+006)) P < 0.0001]. Moreover, the fibrocyte subsets expressing the chemokine markers CXCR4 (P < 0.0001), CCR2 (P < 0.0001), CCR7 (P < 0.0001) and coexpression of both CXCR4 and CCR2 (P < 0.0001) were significantly elevated in patients with hypertensive heart disease compared to controls. Lastly, in patients with hypertensive heart disease there was a strong correlation between left ventricular mass index and total fibrocytes (r = 0.65, P = 0.037) and activated fibrocytes (r = 0.70, P = 0.016).Our data suggest that bone marrow-derived circulating fibrocytes are associated with the presence and extent of left ventricular hypertrophy in patients with hypertensive heart disease.
View details for DOI 10.1097/HJH.0b013e32835639bb
View details for Web of Science ID 000308801600024
View details for PubMedID 22796709
View details for PubMedCentralID PMC3643814
MR Cine DENSE Dyssynchrony Parameters for the Evaluation of Heart Failure Comparison With Myocardial Tissue Tagging
2012; 5 (8): 789-797
We sought to assess the effectiveness of automated mechanical dyssynchrony (MD) parameters based on regional heterogeneity of strain (circumferential [CURE], longitudinal [LURE], and radial uniformity ratio estimates) relative to parameters based on regional time to peak contraction with cardiac magnetic resonance (CMR) cine DENSE (Displacement Encoding with Stimulated Echoes) validated with myocardial tissue tagging (MTT) strain data.Dyssynchrony measures based on the Fourier transformation (FT) of regional strain, such as CURE (previously evaluated in cardiac resynchronization therapy candidates), directly assess MD and yield straightforward global dyssynchrony indexes; however, performance relative to the 12-segment standard deviation of time to peak strain (SD12) or maximal regional delay in time to peak strain is unknown.Cine DENSE and MTT were obtained with CMR (1.5-T Siemens Avanto, Siemens, Erlangen, Germany) in 13 canines: 3 normal control subjects, 5 with tachycardia pacing-induced heart failure (HF) and left bundle branch ablation (LBBB-HF), and 5 with HF and narrow QRS (NQRS-HF). Strain and dyssynchrony parameters were determined with both CMR methods.Both HF groups had reduced peak strains and left ventricular ejection fraction compared with normal cases. There was strong agreement between cine DENSE and MTT on the basis of intraclass correlation coefficients (CURE: 0.99, 95% CI: 0.96 to 1.00; LURE: 0.92, 95% CI: 0.77 to 0.98; circumferential strain [E(CC)]: 0.95, 95% CI: 0.72 to 0.99; longitudinal strain [E(LL)]: 0.82, 95% CI: 0.42 to 0.97). The FT-based metrics (scale 0 to 1), in particular CURE, discriminated highly between LBBB-HF and NQRS-HF groups (median difference): CURE: 0.60, 95% CI: 0.43 to 0.76; LURE: 0.39, 95% CI: 0.19 to 0.58; radial uniformity ratio estimate: 0.22, 95% CI: 0.04 to 0.40). In contrast, relative confidence intervals for group differences in time-to-peak parameters were wide, indicating less consistent discrimination (median difference): SD12-E(CC): 52.5, 95% CI: -4.0 to 109.2; SD12-E(LL): 40.9, 95% CI: -5.3 to 87.1; SD12-radial strain: 42.0, 95% CI: 0.4 to 83.6). Correlations between FT-based and time-to-peak parameters were significant (CURE/SD12-E(CC): r = -0.62, p = 0.03; LURE/SD12-E(LL): r = -0.76, p = 0.005) but not as tight as correlations between time-to-peak parameters.Automated FT-based circumferential, radial, and longitudinal dyssynchrony measures compare favorably with time-to-peak parameters. Cine DENSE was effective for this application and validated with MTT. Further clinical evaluation in cardiac resynchronization therapy candidates with CMR or other imaging modalities is warranted.
View details for DOI 10.1016/j.jcmg.2011.12.024
View details for Web of Science ID 000308588500004
View details for PubMedID 22897992
View details for PubMedCentralID PMC3680367
- LGE and the Risk of Sudden Death in HCM REPLY JACC-CARDIOVASCULAR IMAGING 2012; 5 (7): 762-763
Prognostic Value of Late Gadolinium Enhancement in Clinical Outcomes for Hypertrophic Cardiomyopathy
2012; 5 (4): 370-377
The objective of this study was to perform a systematic review and meta-analysis of the predictive value of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) for future cardiovascular events and death in hypertrophic cardiomyopathy (HCM).The utility of LGE for detecting myocardial fibrosis is well established. The prognostic value of LGE in HCM has been described in several studies, but controversy exists given the limited power of these studies to predict future events.We searched multiple databases including PubMed for studies of LGE in HCM that reported selected clinical outcomes (cardiovascular mortality, sudden cardiac death [SCD], aborted SCD, and heart failure death). We performed a systematic review of the literature and meta-analysis to determine pooled odds ratios for these clinical events.Four studies evaluated 1,063 patients over an average follow-up of 3.1 years. The pooled prevalence of LGE was 60%. The pooled odds ratios (OR) demonstrate that LGE by CMR correlated with cardiac death (pooled OR: 2.92, 95% confidence interval [CI]: 1.01 to 8.42; p = 0.047), heart failure death (pooled OR: 5.68, 95% CI: 1.04 to 31.07; p = 0.045), and all-cause mortality (pooled OR: 4.46, 95% CI: 1.53 to 13.01; p = 0.006), and showed a trend toward significance for predicting sudden death/aborted sudden death (pooled OR: 2.39, 95% CI: 0.87 to 6.58; p = 0.091).Late gadolinium enhancement by CMR has prognostic value in predicting adverse cardiovascular events among HCM patients. There are significant relationships between LGE and cardiovascular mortality, heart failure death, and all-cause mortality in HCM. Additionally, LGE and SCD/aborted SCD displayed a trend toward significance. The assessment of LGE by CMR has the potential to provide important information to improve risk stratification in HCM in clinical practice.
View details for DOI 10.1016/j.jcmg.2011.11.021
View details for Web of Science ID 000302839500006
View details for PubMedID 22498326
Non-invasive imaging and monitoring cardiotoxicity of cancer therapeutic drugs
JOURNAL OF NUCLEAR CARDIOLOGY
2012; 19 (2): 377-388
Cardiotoxicity due to administration of cancer therapeutic agents such as anthracyclines and herceptin are well described. Established guidelines to screen for chemotherapy-related cardiotoxicity (CRC) are primarily based on serial assessment of left ventricular (LV) ejection fraction (EF). However, other parameters such as LV volume, diastolic function, and strain may also be useful in screening for cardiotoxicity. More recent advances in molecular imaging of apoptosis and tissue characterization by cardiac MRI are techniques which might allow early detection of patients at high risk for developing cardiotoxicity prior to a drop in EF. This comprehensive multi-modality review will discuss both the current established imaging techniques as well as the emerging technologies which may revolutionize the future of screening and evaluation for CRC.
View details for DOI 10.1007/s12350-012-9512-2
View details for Web of Science ID 000304403900023
View details for PubMedID 22351492
View details for PubMedCentralID PMC3314105
- FIRST-IN-MAN NOVEL HYBRID PEDIATRIC CARDIAC CATHETERIZATION & MAGNETIC RESONANCE IMAGING SYSTEM ELSEVIER SCIENCE INC. 2012: E167
T2-weighted MRI of post-infarct myocardial edema in mice
MAGNETIC RESONANCE IN MEDICINE
2012; 67 (1): 201-209
T(2) -weighted, cardiac magnetic resonance imaging (T(2) w CMR) can be used to noninvasively detect and quantify the edematous region that corresponds to the area at risk (AAR) following myocardial infarction (MI). Previously, CMR has been used to examine structure and function in mice, expediting the study of genetic manipulations. To date, CMR has not been applied to imaging of post-MI AAR in mice. We developed a whole-heart, T(2) w CMR sequence to quantify the AAR in mouse models of ischemia and infarction. The ΔB(0) and ΔB(1) environment around the mouse heart at 7 T were measured, and a T(2) -preparation sequence suitable for these conditions was developed. Both in vivo T(2) w and late gadolinium enhanced CMR were performed in mice after 20-min coronary occlusions, resulting in measurements of AAR size of 32.5 ± 3.1 (mean ± SEM)% left ventricular mass, and MI size of 50.1 ± 6.4% AAR size. Excellent interobserver agreement and agreement with histology were also found. This T(2) w imaging method for mice may allow for future investigations of genetic manipulations and novel therapies affecting the AAR and salvaged myocardium following reperfused MI.
View details for DOI 10.1002/mrm.22975
View details for Web of Science ID 000298482800023
View details for PubMedID 21630350
View details for PubMedCentralID PMC3188362
- Coronary Angiographic Evaluation of Low-Risk Chest Pain in the Emergency Department CT-STAT, or Maybe Not Quite That Fast? JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 2011; 58 (14): 1423-1425
Optimization of Spiral-Based Pulse Sequences for First-Pass Myocardial Perfusion Imaging
MAGNETIC RESONANCE IN MEDICINE
2011; 65 (6): 1602-1610
Although spiral trajectories have multiple attractive features such as their isotropic resolution, acquisition efficiency, and robustness to motion, there has been limited application of these techniques to first-pass perfusion imaging because of potential off-resonance and inconsistent data artifacts. Spiral trajectories may also be less sensitive to dark-rim artifacts that are caused, at least in part, by cardiac motion. By careful consideration of the spiral trajectory readout duration, flip angle strategy, and image reconstruction strategy, spiral artifacts can be abated to create high-quality first-pass myocardial perfusion images with high signal-to-noise ratio. The goal of this article was to design interleaved spiral pulse sequences for first-pass myocardial perfusion imaging and to evaluate them clinically for image quality and the presence of dark-rim, blurring, and dropout artifacts.
View details for DOI 10.1002/mrm.22746
View details for Web of Science ID 000291115500010
View details for PubMedID 21590802
View details for PubMedCentralID PMC3134590
Prevalence and distribution of regional scar in dysfunctional myocardial segments in Duchenne muscular dystrophy
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE
2011; 13: 20
The segmental relationship between cardiovascular magnetic resonance (CMR) peak circumferential strain (Ecc) and myocardial scar has not been well characterized in Duchenne muscular dystrophy (DMD), and it is unknown whether echocardiography accurately measures Ecc in DMD. We assessed segmental Ecc and scar using CMR with myocardial tissue tagging and late gadolinium enhancement (LGE) in patients with DMD, then compared CMR with echocardiographic velocity vector imaging (VVI) for regional Ecc based on independent observer assessments.Participants enrolled (n = 16; age 8-23) had median left ventricular (LV) ejection fraction of 0.52 (range 0.28-0.69), and 156 basal and mid-cavity myocardial segments from the 13 patients completing the LGE protocol were analyzed for strain and scar. Segmental CMR Ecc in the most negative quartile (quartile 4) ruled out scar in that segment, but scar was present in 46% of segments in the least negative (most dysfunctional) Ecc quartile 1, 33% of Ecc quartile 2 segments, and 15% of Ecc quartile 3 segments. Overall scar prevalence in inferior, inferolateral, and anterolateral segments was eight times higher than in inferoseptal, anteroseptal, and anterior segments (p < 0.001). This increased proportion of scar in lateral versus septal segments was consistent across CMR Ecc quartiles (quartile 1: 76% versus 11%, p = 0.001; quartile 2: 65% versus 9%, p < 0.001; quartile 3: 38% versus 0%, p < 0.001). Echocardiographic analysis could be performed in 12 of 14 patients with CMR exams and had to be limited to mid-cavity slices. Echo segmental Ecc in the most negative quartile made scar by CMR in that segment highly unlikely, but the correlation in segmental Ecc between CMR and echo was limited (r = 0.27; p = 0.02).The relationship between scar and Ecc in DMD is complex. Among myocardial segments with depressed Ecc, scar prevalence was much higher in inferior, inferolateral, and anterolateral segments, indicating a regionally dependent association between abnormal Ecc and scar, with free wall segments commonly developing dysfunction with scar and septal segments developing dysfunction without scar. Although normal echocardiographic Ecc predicted absence of scar, regional echocardiographic Ecc by VVI has only a limited association with CMR Ecc in DMD.
View details for DOI 10.1186/1532-429X-13-20
View details for Web of Science ID 000289428100001
View details for PubMedID 21396105
View details for PubMedCentralID PMC3075215
Improved Detection of Subendocardial Hyperenhancement in Myocardial Infarction Using Dark Blood-Pool Delayed Enhancement MRI
AMERICAN JOURNAL OF ROENTGENOLOGY
2011; 196 (2): 339-348
Delayed enhancement MRI using fast segmented k-space inversion recovery (IR) gradient-echo imaging is a well established "bright-blood" technique for identifying myocardial infarction and is used as the reference standard sequence in this study. The purpose of this study was to validate a recently developed dark blood-pool delayed enhancement technique in a porcine animal model, evaluate its performance in human patients, and quantify its performance compared with the reference standard in both.In an animal study, the reference standard and dark blood-pool delayed enhancement were assessed in three pigs with induced myocardial infarction. In a human study, 26 patients, 31-81 years old (19 men and seven women), with a known history of myocardial infarction were imaged using the reference standard and dark blood-pool delayed enhancement. Contrast-to-noise ratio (CNR), signal intensity ratio, signal-to-noise ratio (SNR), and qualitative scores of hyperenhancement were recorded. Measurements were compared using paired samples t test and Wilcoxon's signed rank test.In the animal study, the mean CNR of infarct to blood pool was 11 times higher for dark blood-pool delayed enhancement than for the reference standard. The mean SNR was 4.4 times higher for the reference standard. In the human study, the mean CNR and signal intensity ratio of hyperenhancing myocardium to the blood pool were 1.9 (p = 0.04) and 5.5 (p < 0.01) times higher, respectively, for dark blood-pool delayed enhancement compared with reference standard. The mean CNR and signal intensity ratio of hyperenhancing myocardium to normal myocardium and SNR were 2.8 (p < 0.01), 1.3 (p = 0.07), and 2.8 (p < 0.01) higher, respectively, for the reference standard. Qualitative analysis identified seven extra segments with grade 1 scars using dark blood-pool delayed enhancement (p < 0.01).Dark blood-pool delayed enhancement is complementary to the reference standard. It can detect more subendocardial foci of hyperenhancement, thus potentially identifying more infarcts and changing patient management.
View details for DOI 10.2214/AJR.10.4418
View details for Web of Science ID 000287135600017
View details for PubMedID 21257885
The Role of Cardiac Magnetic Resonance in the Evaluation of Patients Presenting with Suspected or Confirmed Acute Coronary Syndrome
CARDIOLOGY RESEARCH AND PRACTICE
2011; 2011: 605785
Cardiac magnetic resonance imaging (CMR) has an important emerging role in the evaluation and management of patients who present with symptoms concerning for acute coronary syndrome (ACS). This paper discusses the role of CMR in the emergency department setting, where CMR can aid in the early and accurate diagnosis of non-ST elevation ACS in low and intermediate risk patients. For those with confirmed myocardial infarction (MI), CMR provides comprehensive prognostic information and can readily diagnose structural complications related to MI. Furthermore, the pattern of late gadolinium enhancement (LGE) seen on CMR can help determine the etiology of cardiac injury in the subset of patients presenting with ACS who do not have obstructive coronary artery disease by angiography.
View details for DOI 10.4061/2011/605785
View details for Web of Science ID 000214709000077
View details for PubMedID 22028981
View details for PubMedCentralID PMC3199125
- Prognosis in Hypertrophic Cardiomyopathy With Contrast-Enhanced Cardiac Magnetic Resonance The Future Looks Bright JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 2010; 56 (11): 888-889
Assessment of Advanced Coronary Artery Disease Advantages of Quantitative Cardiac Magnetic Resonance Perfusion Analysis
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2010; 56 (7): 561-569
The purpose of this paper was to compare quantitative cardiac magnetic resonance (CMR) first-pass contrast-enhanced perfusion imaging to qualitative interpretation for determining the presence and severity of coronary artery disease (CAD).Adenosine CMR can detect CAD by measuring perfusion reserve (PR) or by qualitative interpretation (QI).Forty-one patients with an abnormal nuclear stress scheduled for X-ray angiography underwent dual-bolus adenosine CMR. Segmental myocardial perfusion analyzed using both QI and PR by Fermi function deconvolution was compared to quantitative coronary angiography.In the 30 patients with complete quantitative data, PR (mean +/- SD) decreased stepwise as coronary artery stenosis (CAS) severity increased: 2.42 +/- 0.94 for <50%, 2.14 +/- 0.87 for 50% to 70%, and 1.85 +/- 0.77 for >70% (p < 0.001). The PR and QI had similar diagnostic accuracies for detection of CAS >50% (83% vs. 80%), and CAS >70% (77% vs. 67%). Agreement between observers was higher for quantitative analysis than for qualitative analysis. Using PR, patients with triple-vessel CAD had a higher burden of detectable ischemia than patients with single-vessel CAD (60% vs. 25%; p = 0.02), whereas no difference was detected by QI (31% vs. 21%; p = 0.26). In segments with myocardial scar (n = 64), PR was 3.10 +/- 1.34 for patients with CAS <50% (n = 18) and 1.91 +/- 0.96 for CAS >50% (p < 0.0001).Quantitative PR by CMR differentiates moderate from severe stenoses in patients with known or suspected CAD. The PR analysis differentiates triple- from single-vessel CAD, whereas QI does not, and determines the severity of CAS subtending myocardial scar. This has important implications for assessment of prognosis and therapeutic decision making.
View details for DOI 10.1016/j.jacc.2010.02.061
View details for Web of Science ID 000280609200005
View details for PubMedID 20688211
View details for PubMedCentralID PMC2930835
Multi-modality imaging of diastolic function
JOURNAL OF NUCLEAR CARDIOLOGY
2010; 17 (2): 316-327
Non-invasive evaluation of diastolic function continues to play a critical role in furthering our understanding of diastole, improving the diagnosis of diastolic dysfunction, evaluating left ventricular filling pressures, and providing important prognostic information for patients with heart failure. Echocardiography, cardiovascular magnetic resonance, and nuclear cardiology each provide important tools for evaluating diastolic performance. This review will focus on the techniques from multiple cardiovascular imaging modalities which have been used for the clinical assessment of diastolic function.
View details for DOI 10.1007/s12350-010-9196-4
View details for Web of Science ID 000275778800020
View details for PubMedID 20165993
- Noninvasive Assessment of Myocardial Perfusion CIRCULATION-CARDIOVASCULAR IMAGING 2009; 2 (5): 412-424
Prognostic validation of an algorithm to convert myocardial perfusion SPECT imaging data from a 12-segment model to a 17-segment model
JOURNAL OF NUCLEAR CARDIOLOGY
2009; 16 (4): 605-613
A 17-segment model has become the standard for interpreting myocardial perfusion single-photon emission computed tomography (SPECT). Methods for converting pre-existing databases from 12-segment models to the 17-segment model are needed for ongoing prognostic studies.To develop the conversion algorithm, 150 consecutive SPECT studies (82 abnormal) were read by both a 12-segment and the standard 17-segment models. Summed stress scores (SSSs) were calculated from a 17-segment model derived from the 12-segment data and compared to those of the standard 17-segment model. The effect of the conversion algorithm on prognostic data derived from the 12-segment model was evaluated in 25,876 patients from the Duke Nuclear Cardiology Database, including a sample of 3,205 patients with known covariates for adjusted analysis. The derived 17-segment SSS from the 12-segment model was highly correlated (R = 0.99) to the SSS from the standard 17-segment model. In both unadjusted and adjusted analysis, there was no difference in the prognostic information.An algorithm for conversion of 12-segment perfusion scores to 17-segment scores has been developed which is highly correlated to visual interpretation by the 17-segment model with nearly identical prognostic information.
View details for DOI 10.1007/s12350-009-9103-z
View details for Web of Science ID 000267913000017
View details for PubMedID 19495902
View details for PubMedCentralID PMC2803346
Evaluation of emphysema severity and progression in a rabbit model: comparison of hyperpolarized He-3 and Xe-129 diffusion MRI with lung morphometry
JOURNAL OF APPLIED PHYSIOLOGY
2007; 102 (3): 1273-1280
The apparent diffusion coefficients (ADCs) of hyperpolarized (3)He and (129)Xe gases were measured in the lungs of rabbits with elastase-induced emphysema and correlated against the mean chord length from lung histology. In vivo measurements were performed at baseline and 2, 4, 6, and 8 wk after instillation of elastase (mild and moderate emphysema groups) or saline (control group). ADCs were determined from acquisitions that used two b values. To investigate the effect of b value on the results, b-value pairs of 0 and 1.6 s/cm(2) and 0 and 4.0 s/cm(2) were used for (3)He, and b-value pairs of 0 and 5.0 s/cm(2) and 0 and 10.0 s/cm(2) were used for (129)Xe. At 8 wk after instillation, the rabbits were euthanized, and the lungs were analyzed histologically and morphometrically. ADCs for the rabbits in the control group did not change significantly from baseline to week 8, whereas ADCs for the rabbits in the emphysema groups increased significantly (P < 0.05) for all gas and b-value combinations except (129)Xe with the b-value pair of 0 and 5.0 s/cm(2). The largest percent change in mean ADC from baseline to week 8 (15.3%) occurred with (3)He and the b-value pair of 0 and 1.6 s/cm(2) for rabbits in the moderate emphysema group. ADCs (all b values) were strongly correlated (r = 0.62-0.80, P < 0.001) with mean chord lengths from histology. These results further support the ability of diffusion-weighted MRI with hyperpolarized gases to detect regional and global structural changes of emphysema within the lung.
View details for DOI 10.1152/japplphysiol.00418.2006
View details for Web of Science ID 000244722400060
View details for PubMedID 17110518
The effects of SNR on ADC measurements in diffusion-weighted hyperpolarized He-3 MRI
JOURNAL OF MAGNETIC RESONANCE
2007; 185 (1): 42-49
The theoretical dependence of the mean and standard deviation of ADC values on signal-to-noise ratio (SNR) was derived and compared to measured values in porous phantoms and the lungs of human subjects using diffusion-weighted hyperpolarized helium-3 MRI. For SNR values below 15, mean ADC values were highly SNR-dependent due to a combination of noise and choice of noise thresholding. Above SNR values of 15 and for mean ADC values within ranges relevant for evaluating lung disease (<0.6 cm2/s), the mean ADC was largely independent of SNR. The standard deviation, by contrast, was highly dependent on SNR over a much larger range, but this dependence was well predicted by theory, suggesting the histogram of ADC values might be corrected for these stochastic processes to more accurately evaluate disease using restricted diffusion measures in the lungs.
View details for DOI 10.1016/j.jmr.2006.11.006
View details for Web of Science ID 000245688100006
View details for PubMedID 17150391
Detection of age-dependent changes in healthy adult lungs with diffusion-weighted He-3 MRI
ASSOC UNIV RADIOLOGISTS. 2005: 1385-1393
To investigate changes in lung microstructure in healthy adult subjects with no smoking history using diffusion-weighted 3He MRI.Diffusion magnetic resonance imaging using hyperpolarized helium 3 (3He) was applied to healthy volunteers to explore the dependence of lung microstructural changes with age, reflected by changes in the apparent diffusion coefficient (ADC) of 3He in lung air spaces. Data from three sites (University of Virginia (UVa), N = 25; University of Wisconsin (UW), N = 8; University of Nottingham (UN), N = 11) were combined in pooled analysis, including a total of N = 44 subjects (age range, 18-69 years; average age, 41.7 +/- 16.7 years).ADC was found to depend on age at all three sites (UW, R = +0.95, P = .0003; UVa, R = +0.74, P < .0001; UN, R = +0.96, P < .0001). Increases in mean ADCs with age appeared similar across sites (UW, +0.0017 cm2 s(-1) y(-1); UVa, +0.0015 cm2 s(-1) y(-1); pooled, +0.0015 cm2 s(-1) y(-1); P = .71). In a regional analysis performed on UW data, the increase in ADC affected all regions of the lung, but the apical and middle regions showed a greater increase compared with the base of the lung.Results suggest the observed age dependence of the ADC may be caused by changes in lung microstructure that increase alveolar volume during the aging process.
View details for DOI 10.1016/j.acra.2005.08.005
View details for Web of Science ID 000233099000005
View details for PubMedID 16253850
Hyperpolarized He-3 lung imaging at 0.5 and 1.5 tesla: A study of susceptibility-induced effects
MAGNETIC RESONANCE IN MEDICINE
2005; 53 (1): 212-216
Hyperpolarized (3)He MRI of the human lung was performed at 0.54 and 1.5 T using identical software and hardware (except for RF coils) at both field strengths. The T(*) (2) of (3)He gas in the lung was measured, and the effects of magnetic-susceptibility-induced field inhomogeneities on the appearance of interleaved-spiral and interleaved-echo-planar lung images at 1.5 T were compared to those at 0.54 T. Mean T(*) (2) values for (3)He gas in the healthy human lung were 26.8 +/- 1.5 ms and 67.9 +/- 1.3 ms at 1.5 and 0.54 T, respectively. At 0.54 T, interleaved-spiral images showed markedly less blurring due to susceptibility effects compared to images acquired at 1.5 T. At both 0.54 and 1.5 T, interleaved-echo-planar images appeared essentially identical to corresponding GRE images, even though the data-sampling period per echo and echo time were substantially longer for the interleaved-echo-planar images acquired at 0.54 T.
View details for DOI 10.1002/mrm.20329
View details for Web of Science ID 000226380700028
View details for PubMedID 15690521
Hyperpolarized gas MR imaging of the lung
JOURNAL OF THORACIC IMAGING
2004; 19 (4): 250-258
Hyperpolarized gases belong to a new class of MR contrast agents that, when inhaled, provide high temporal and spatial resolution images of the lung airspaces. At this time, hyperpolarized gas MRI is only being performed at a limited number of institutions. However, the availability of hyperpolarized gas MRI could increase dramatically in coming years as regulatory hurdles within the U.S. are surmounted. The intent of this paper is to provide an introduction to hyperpolarized gas MRI for the thoracic radiologist. It includes a description of the basic principles of hyperpolarized gas MRI and a review of the results of preliminary clinical investigations with this method.
View details for DOI 10.1097/01.rti.0000142837.52729.38
View details for Web of Science ID 000224839400006
View details for PubMedID 15502612
Ventilation imaging of the lung: Comparison of hyperpolarized helium-3 MR imaging with Xe-133 scintigraphy
2004; 11 (7): 729-734
To compare hyperpolarized helium-3 (HHe) magnetic resonance imaging (MRI) of the lung with standard Xe-133 lung ventilation scintigraphy.We performed a retrospective review of 15 subjects who underwent HHe MRI and Xe-133 lung ventilation imaging. Coronal MRI sections were acquired after a single inhalation of HHe gas, and standard posterior planar lung ventilation scintigraphy was performed during continuous breathing of Xe-133 gas. The first breath scintigram of each patient was compared with a composite MR image composed of the sum of the individual MR images and with the individual helium-3 MR images. Ventilation defects on the two imaging modalities were compared for size, conspicuity, and concordance in presence and location. Assessment was done separately for each of four lung quadrants.Comparing the composite HHe MR images with Xe-133 scintigraphy, ventilation defect size, conspicuity and concordance were the same in 67% (40/60), 63% (38/60), and 62% (37/60) quadrants, respectively. Comparing the individual HHe MR image sections with the Xe-133 ventilation scan, there was concordance between the ventilation defects in 27% (16/60) of quadrants. More defects were identified on the individual HHe MR images in 62% (37/60) of quadrants.There was good agreement between composite HHe MR image and first breath Xe-133 scintigraphic images, supporting the widely held assumption that HHe MRI likely depicts first breath lung ventilation.
View details for DOI 10.1016/j.acra.2004.04.001
View details for Web of Science ID 000222369800003
View details for PubMedID 15217589
Rapid hyperpolarized He-3 diffusion MRI of healthy and emphysematous human lungs using an optimized interleaved-spiral pulse sequence
JOURNAL OF MAGNETIC RESONANCE IMAGING
2003; 17 (5): 581-588
To develop and validate an interleaved-spiral diffusion pulse sequence capable of hyperpolarized (3)He MR imaging of the whole lung in less than 10 seconds.Hyperpolarized (3)He diffusion measurements were performed in seven healthy volunteers and five patients with emphysema using an interleaved-spiral pulse sequence that provided 11 contiguous 15-mm thick coronal ADC maps, with an in-plane resolution of 3.9 mm, covering the whole lung in 5.5 seconds. The resulting means and SDs of ADC values were compared statistically to those from a gradient-echo pulse sequence with identical resolution and diffusion-weighting gradients that acquired five ADC maps in 10.5 seconds.High-quality diffusion-weighted interleaved-spiral images covering the whole lung were obtained, and showed no significant susceptibility-induced image degradation compared to corresponding gradient-echo images. On a subject-by-subject basis, the means and SDs of ADC values for the interleaved-spiral technique were not statistically different from those for the gradient-echo technique. The mean ADC values from the two techniques were highly correlated on a section-by-section basis (R = 0.99).The interleaved-spiral diffusion pulse sequence permits rapid acquisition of contiguous ADC maps covering the whole lung during a short breath-hold period, and provides ADC values that are statistically equivalent to those from standard gradient-echo techniques.
View details for DOI 10.1002/jmri.10303
View details for Web of Science ID 000182630800009
View details for PubMedID 12720268
Emphysema: Hyperpolarized helium 3 diffusion MR imaging of the lungs compared with spirometric indexes - Initial experience
2002; 222 (1): 252-260
To quantitatively evaluate hyperpolarized helium 3 ((3)He) diffusion magnetic resonance (MR) images of the lung in patients with emphysema and to determine whether apparent diffusion coefficients (ADCs) measured with MR imaging correlate with spirometric indexes.Hyperpolarized (3)He diffusion MR imaging was performed in 16 healthy volunteers and 11 patients. Coronal diffusion-sensitized MR images were obtained during suspended respiration after inhalation of laser-polarized (3)He gas, and images of the ADC were calculated. Spirometry was performed immediately before imaging. The mean and SD of the ADCs were compared between subject groups and were correlated with spirometric indexes.ADC images were homogeneous in volunteers, but demonstrated regional variations in patients. The mean and SD of the ADCs for patients were significantly larger (P <.002) than those for volunteers. The mean ADCs for all subjects correlated with the percentage of predicted forced expiratory volume in 1 second, or FEV(1), (r = -0.797, P <.001) and the ratio of FEV(1) to forced vital capacity, or FVC, (r = -0.930, P <.001). ADC images in patients demonstrated a significant increase (P <.001) in the ADCs in the upper regions compared with the lower regions of the lung.Hyperpolarized (3)He diffusion MR imaging demonstrated potential for use in evaluating the global and regional severity of emphysema.
View details for DOI 10.1148/radiol.2221001834
View details for Web of Science ID 000172884800038
View details for PubMedID 11756734
Dynamic spiral MRI of pulmonary gas flow using hyperpolarized He-3: Preliminary studies in healthy and diseased lungs
MAGNETIC RESONANCE IN MEDICINE
2001; 46 (4): 667-677
An optimized interleaved-spiral pulse sequence, providing high spatial and temporal resolution, was developed for dynamic imaging of pulmonary ventilation with hyperpolarized (3)He, and tested in healthy volunteers and patients with lung disease. Off-resonance artifacts were minimized by using a short data-sampling period per interleaf, and gradient-fidelity errors were compensated for by using measured k-space trajectories for image reconstruction. A nonsequential acquisition order was implemented to improve image quality during periods of rapid signal change, such as early inspiration. Using a sliding-window reconstruction, cine-movies with a frame rate of 100 images per second were generated. Dynamic images demonstrating minimal susceptibility- and motion-induced artifacts were obtained in sagittal, coronal, and axial orientations. The pulse sequence had the flexibility to image multiple slices almost simultaneously. Our initial experience in healthy volunteers and subjects with lung pathology demonstrated the potential of this new tool for capturing the features of lung gas-flow dynamics.
View details for DOI 10.1002/mrm.1244
View details for Web of Science ID 000171217600005
View details for PubMedID 11590642