Clinical Focus

  • Genitourinary Imaging
  • Urology Imaging
  • Gynecology Imaging
  • Body Imaging

Academic Appointments

  • Clinical Associate Professor, Radiology

Administrative Appointments

  • Co-Medical Director, Point of Care Ultrasound (2021 - Present)

Honors & Awards

  • Peer Review Excellence Award, Abdominal Radiology, Abdominal Radiology (Journal) (2023)
  • RSNA educational exhibit Cum Laude award, Radiological Society of North America (RSNA) (2023)
  • SAR Best Overall Paper, Roscoe E. Miller Award, Society of Abdominal Radiology (SAR) (2023)
  • Selected for Council of Early Career Investigators in Imaging (CECI¬2), Society of Radiologists in Ultrasound (SRU) (2023)
  • SAR educational exhibit Cum Laude award, Society of Abdominal Radiology (SAR) (2022)
  • Selected for the AUR Academic Faculty Development Program, Association of University Radiologists (AUR) (2022)
  • Selected for the Stanford Junior Leadership Bootcamp Series, Stanford Office of Faculty Development and Diversity (OFDD) (2022)
  • Selected for the Stanford Medicine Physician Leadership Certification Program (SPLC), Stanford Office of Faculty Development and Diversity (OFDD) (2022)
  • ARRS educational exhibit Certificate of Merit, American Roentgen Ray Society (ARRS) (2020)
  • SAR educational exhibit Certificate of Merit, Society of Abdominal Radiology (SAR) (2020)
  • RSNA educational exhibit Certificate of Merit, Radiological Society of North America (RSNA) (2014)
  • Alpha Omega Alpha Honor Medical Society, University of Cincinnati College of Medicine (2011)
  • Distinguished Honors Scholar, University of Cincinnati Honors Program (2008)
  • Phi Beta Kappa Society, University of Cincinnati (2008)
  • Summa Cum Laude, Unversity of Cincinnati (2008)
  • University of Cincinnati College of Medicine ROSE early acceptance program, University of Cincinnati College of Medicine (2006)

Boards, Advisory Committees, Professional Organizations

  • Associate editor, Abdominal Radiology (NY) (2023 - Present)
  • Co-chair, Society of Radiologists in Ultrasound (SRU) Early Career Interest Group (2023 - Present)
  • Editorial board member, American Journal of Kidney Disease (AJKD) (2023 - Present)
  • Member, Society of Abdominal Radiology (SAR) Scientific Program Committee (2023 - Present)
  • Co-chair (since 2024); chair of research committee (2022-2024), member (since 2022), Society of Abdominal Radiology (SAR) Advanced Ultrasound Techniques committee (2022 - Present)
  • Member, Society of Radiologists in Ultrasound (SRU) Research Committee (2022 - Present)
  • Member, Society of Abdominal Radiology (SAR) Disease Focused Panel (DFP) Renal Cell Carcinoma (2022 - Present)
  • Member, Society of Abdominal Radiology (SAR) Disease Focused Panel (DFP) Endometriosis (2022 - Present)
  • Member, steering committee, Society of Abdominal Radiology (SAR) Disease Focused Panel (DFP) Uterine and Ovarian Cancer (2022 - Present)
  • Peer reviewer, RadioGraphics (2022 - Present)
  • Peer reviewer, American Journal of Roentgenology (AJR) (2022 - Present)
  • Member, Society of Abdominal Radiology (SAR) Disease Focused Panel (DFP) Pelvic Floor Dysfunction (2021 - Present)
  • Member, Society of Radiologists in Ultrasound (SRU) (2021 - Present)
  • Editorial board member, European Journal of Radiology Open (EJRO) (2021 - 2023)
  • Member, Society of Abdominal Radiology (SAR) International Task Force Committee (2021 - 2023)
  • Member, American College of Radiology (ACR) (2019 - Present)
  • Member, Society of Abdominal Radiology (SAR) (2019 - Present)
  • Peer reviewer, European Journal of Radiology (2019 - 2020)
  • Peer reviewer, Abdominal Radiology (NY) (2018 - Present)
  • Member, Radiological Society of North America (RSNA) (2013 - Present)

Professional Education

  • Fellowship: UCLA Radiology Fellowships (2018) CA
  • Residency: UCLA Radiology Residency (2017) CA
  • Internship: University of California Irvine Dept of Internal Medicine (2013) CA
  • Medical Education: University of Cincinnati College of Medicine Registrar (2012) OH
  • Board Certification: American Board of Radiology, Diagnostic Radiology (2018)

Community and International Work

  • RAD-AID Radiology Serving the World, China


    RAD-AID China

    Populations Served

    Underserved areas in China



    Ongoing Project


    Opportunities for Student Involvement


Current Research and Scholarly Interests

GU and Gyn clinical imaging

Clinical Trials

  • Serial Ultrasound of Solid Tumor Lesions to Detect Early Response to Cancer Immunotherapy Recruiting

    Primary objective is to assess whether changes in quantitative tumor perfusion parameters after 3 weeks of treatment, as measured by CEUS, can predict initial objective response to therapy, defined by current standard-of-care Secondary objectives are to evaluate if there is an optimal ultrasound imaging modality (CEUS or conventional power Doppler or LEAD ultrasound) or optimal time point to predict initial objective response and to assess the correlation of tumor perfusion parameters with change in overall tumor burden, change in diameter on a per-lesion basis, and with 12-month progression-free survival (PFS).

    View full details

All Publications

  • Differentiation of Hepatocellular Adenoma Subtypes and Focal Nodular Hyperplasia on Gadoxetate Disodium-Enhanced MRI: An Updated Diagnostic Algorithm. AJR. American journal of roentgenology Cao, J. J., Shen, L., Yoon, L., Kamaya, A., Tse, J. R. 2024

    View details for DOI 10.2214/AJR.24.31628

    View details for PubMedID 39016449

  • Follow-up imaging and surgical costs associated with different guidelines for management of incidentally detected gallbladder polyps. Academic radiology Vo-Phamhi, J. M., Tiyarattanachai, T., Matuszczak, M., Shen, L., Kim, S., Kamaya, A. 2024


    To compare follow-up imaging and surgical cost implications of the Society of Radiologists in Ultrasound (SRU) guidelines, 2017 and 2022 European (EUR) guidelines, 2020 Canadian Association of Radiologists (CAR) recommendations, and 2013 American College of Radiology (ACR) White Paper for managing incidentally detected gallbladder polyps.253 consecutive patients with gallbladder polyps identified on ultrasound were independently reviewed by three radiologists for polyp size and morphology. Electronic medical records were reviewed for patient demographics, cholecystectomy (if performed) pathological findings, or any subsequent diagnosis of gallbladder cancer. For each patient, the following were calculated for each of the 5 guidelines studied: 1) number of recommended follow-up ultrasounds based on initial presentation, 2) number of surgical consultations recommended based on initial presentation, 3) number of surgical consultations recommended based on growth, and 4) associated imaging and surgical costs. Interrater agreement was calculated.The SRU 2022 guidelines suggested significantly fewer follow-up ultrasounds and surgical consultations, leading to a cost reduction of 96.5 % and 96.7 % compared to European 2022 and 2017, respectively; 86.5 % compared to CAR; and 86.2 % compared to ACR guidelines. With SRU Recommendations, the majority of gallbladder polyps would be classified as extremely low risk (68.4 %), 30.8 % low risk, and 0.8 % indeterminate risk. In our cohort, a single case of gallbladder cancer was identified (26 mm) which would be recommended for surgical consult by all guidelines.The SRU 2022 guidelines can lead to significant savings for patients, health systems, and society, while reducing unnecessary medical interventions for managing incidentally detected gallbladder polyps.

    View details for DOI 10.1016/j.acra.2024.05.034

    View details for PubMedID 38862347

  • Gastrointestinal devices: common and uncommon foreign bodies. Abdominal radiology (New York) Shen, L., Aslan, E., Cao, J. J., Shen, J., Tse, J. R. 2024


    Devices for the gastrointestinal tract are widely available and constantly advancing with less invasive techniques. They play a crucial role in diagnostic and therapeutic interventions and are commonly placed by interventional radiologists, gastroenterologists, and surgeons. These devices frequently appear in imaging studies, which verify their proper placement, identify any complications, or may be incidentally detected. Radiologists must be able to identify these devices at imaging and understand their intended purpose to assess their efficacy, detect complications such as incorrect positioning, and avoid misinterpreting them as abnormalities. Furthermore, many patients with these devices may require MRI, making assessing compatibility essential for safe patient care. This review seeks to provide a succinct and practical handbook for radiologists regarding both common and uncommon gastrointestinal devices. In addition to textual descriptions of clinical indications, imaging findings, complications, and MRI compatibility, the review incorporates a summary table as a quick reference point for key information and illustrative images for each device.

    View details for DOI 10.1007/s00261-024-04336-2

    View details for PubMedID 38831074

    View details for PubMedCentralID 4640916

  • World Health Organization (WHO) 2022 Classification Update: Radiologic and Pathologic Features of Papillary Renal Cell Carcinomas. Academic radiology Shen, L., Yoon, L., Mullane, P. C., Liang, T., Tse, J. R. 2024


    To describe imaging and pathology features of newly defined papillary renal cell carcinoma (pRCC) based on the WHO 2022 update.This retrospective study included 87 patients with 93 pathologically proven papillary renal cell carcinomas who underwent pre-treatment renal mass protocol CT or MRI. Baseline and post-treatment follow-up imaging was evaluated by two radiologists systematically based on established lexicon.At pathology, 63 (68%) were grade 1-2, 29 (31%) were grade 3-4, and 1 (%) was unreported. At surgical pathology, 84 (90%) were localized (≤pT2b), 5 (5%) were pT3a, and none were ≥pT3b; 4 (4%) had unknown pT stage (core biopsies). 33 (35%) had necrosis and 39 (41%) had hemorrhage. None had sarcomatoid or rhabdoid differentiation. At imaging, 73 (83%) were solid and 16 (17%) were cystic. Of 16 cystic masses, four were Bosniak class IIF (three were heterogeneously T1 hyperintense) and 12 were class IV. All were well-circumscribed. 92 (99%) were hypovascular. Median follow-up for 74 patients was 30 months (IQR 12-56). One untreated patient had non-regional nodal metastasis at presentation, and one patient had metastasis to lymph nodes and bones after surgery, but the patient had unresected renal masses elsewhere without pathology. Otherwise, no recurrence or metastases were detected.Most pRCCs present as a hypovascular, circumscribed, solid renal mass. A few pRCCs present as the newly defined Bosniak class IIF subtype. Our results can form the basis of a non-invasive, likelihood score to identify this relatively indolent pathology in the era of virtual biopsy and active surveillance.

    View details for DOI 10.1016/j.acra.2024.01.034

    View details for PubMedID 38365492

  • Beta-Catenin-Mutated Hepatocellular Adenomas at Hepatobiliary Phase MRI: A Systematic Review and Meta-Analysis JOURNAL OF MAGNETIC RESONANCE IMAGING Shen, L., Altmayer, S., Tse, J. R. 2024

    View details for DOI 10.1002/jmri.29279

    View details for Web of Science ID 001162103000001

  • Beta-Catenin-Mutated Hepatocellular Adenomas at Hepatobiliary Phase MRI: A Systematic Review and Meta-Analysis. Journal of magnetic resonance imaging : JMRI Shen, L., Altmayer, S., Tse, J. R. 2024


    Beta-catenin-mutated hepatocellular adenomas (β-HCAs) can appear iso- to hyperintense at the hepatobiliary phase (HBP) at magnetic resonance imaging (MRI). Given the relatively lower prevalence of β-HCAs, prior studies had limited power to show statistically significant differences in the HBP signal intensity between different subtypes.To assess the diagnostic performance of HBP MRI to discriminate β-HCA from other subtypes.Systemic review and meta-analysis.Ten original studies were included, yielding 266 patients with 397 HCAs (9%, 36/397 β-HCAs and 91%, 361/397 non-β-HCAs).1.5 T and 3.0 T, HBP.PubMed, Web of Science, and Embase databases were searched from January 1, 2000, to August 31, 2023, for all articles reporting HBP signal intensity in patients with histopathologically proven HCA subtypes. QUADAS-2 was used to assess risk of bias and concerns regarding applicability.Univariate random-effects model was used to calculate pooled estimates. Heterogeneity estimates were assessed with I2 heterogeneity index. Meta-regression (mixed-effect model) was used to test for differences in the prevalence of HBP signal between HCA groups. The threshold for statistical significance was set at P < 0.05.HBP iso- to hyperintensity was associated with β-HCAs (pooled prevalence was 72.3% in β-HCAs and 6.3% in non-β-HCAs). Pooled sensitivity and specificity were 72.3% (95% confidence interval 54.1-85.3) and 93.7% (93.8-97.7), respectively. Specificity had substantial heterogeneity with I2 of 83% due to one study, but not for sensitivity (I2  = 0). After excluding this study, pooled sensitivity and specificity were 77.4% (59.6-88.8) and 94.1% (88.9-96.9), with no substantial heterogeneity. One study had high risk of bias for patient selection and two studies were rated unclear for two domains.Iso- to hyperintensity at HBP MRI may help to distinguish β-HCA subtype from other HCAs with high specificity. However, there was heterogeneity in the pooled estimates.3 TECHNICAL EFFICACY: Stage 2.

    View details for DOI 10.1002/jmri.29279

    View details for PubMedID 38465878

  • Establishing a Point-of-Care Ultrasound (POCUS) Program: An Institutional Approach for Developing a POCUS Program Infrastructure. Journal of the American College of Radiology : JACR Shen, L., Lobo, V. E., Cordova, D., Larson, D. B., Kamaya, A. 2023


    Point of care ultrasound (POCUS) is rapidly accelerating in adoption and applications outside of the traditional realm of diagnostic radiology departments. While utilization of this imaging technology in a distributed fashion has great potential, there are many associated challenges. To address these challenges, we developed an enterprise-wide POCUS program at our institution (Stanford Health Care). Here, we share our experience, the governance organization, our approach to device and information security, training, and quality assurance. We also share our basic principles we use to guide our approach to manage these challenges. Through our work, we have learned that a foundational framework of defining POCUS, the different levels of POCUS use, and delineating program management elements are critical. We hope our experience may be helpful to others who are also interested in POCUS or in the process of creating a POCUS program in their institution. With a clearly established framework, patient safety and quality of care are improved for everyone.

    View details for DOI 10.1016/j.jacr.2023.10.026

    View details for PubMedID 37984768

  • Risk of malignancy in T1-hyperintense Bosniak version 2019 class II and IIF cystic renal masses. Abdominal radiology (New York) Shen, L., Tse, J. R., Lemieux, S., Yoon, L., Mullane, P. C., Liang, T., Davenport, M. S., Pedrosa, I., Silverman, S. G. 2023


    Bosniak classification version 2019 includes cystic masses in class II and IIF based partly on their hyperintense appearance at T1-weighted MRI. The prevalence of malignancy in non-enhancing heterogeneously T1-hyperintense masses is unknown, nor whether the pattern of T1 hyperintensity affects malignancy likelihood.To determine the malignancy proportion among six patterns of T1 hyperintensity within non-enhancing cystic renal masses.This retrospective, single-institution study included 72 Bosniak class II and IIF, non-enhancing, T1-hyperintense cystic renal masses. Diagnosis was confirmed by histopathology or by follow-up imaging demonstrating 5-year size and morphologic stability, decreased in size by ≥ 30%, resolution, or Bosniak down-classification. Six patterns of T1 hyperintensity were pre-defined: homogeneous (pattern A), fluid-fluid level (pattern B), peripherally markedly T1-hyperintense (pattern C), containing a T1-hyperintense non-enhancing nodule (pattern D), peripherally T1-hypointense (pattern E), and heterogeneously T1-hyperintense without a distinct pattern (pattern F). Three readers independently assigned each mass to a pattern. Individual and mean malignancy proportion were determined. Mann-Whitney test and Fischer's exact test compared the likelihood of malignancy between patterns. Inter-reader agreement was analyzed with Gwet's agreement coefficient (AC).Among 72 masses, the mean number of masses assigned was 11 (15%) to pattern A, 21 (29%) to pattern B, 6 (8%) to pattern C, 7 (10%) to pattern D, 5 (7%) to pattern E, and 22 (31%) to pattern F. Five of 72 masses (7%) were malignant; none was assigned pattern A, B, or D. Mean malignancy proportion was 5% (0/9, 1/6, and 0/4) for pattern C, 13% (0/4, 1/3, and 1/7) for pattern E, and 18% (5/20, 3/21, and 4/25) for pattern F. Malignant masses were more likely assigned to pattern E or F (p = 0.003-0.039). Inter-reader agreement was substantial (Gwet's AC: 0.68).Bosniak version 2019 class IIF masses that are non-enhancing and heterogeneously T1-hyperintense with a fluid-fluid level are likely benign. Those that are non-enhancing and heterogeneously T1-hyperintense without a distinct pattern have a malignancy proportion up to 25% (5/20).

    View details for DOI 10.1007/s00261-023-03955-5

    View details for PubMedID 37202641

    View details for PubMedCentralID 2550668

  • External Validation of a Five-Tiered CT Algorithm for the Diagnosis of Clear-Cell Renal Cell Carcinoma: A Retrospective Five-Reader Study. AJR. American journal of roentgenology Lemieux, S., Shen, L., Liang, T., Lo, E., Chu, Y., Kamaya, A., Tse, J. R. 2023


    Background: A 5-tiered CT algorithm was proposed in 2022 for predicting whether a small (cT1a) solid renal mass represents clear-cell renal cell carcinoma (ccRCC). Purpose: To perform an external-validation study of the proposed CT algorithm for diagnosis of ccRCC among small solid renal masses. Methods: This retrospective study included 93 patients [median age, 62 years; 42 women, 51 men] with 97 small solid renal masses on corticomedullary-phase contrast-enhanced CT performed between January 2012 and July 2022 that underwent surgical resection. Five readers (three attending radiologists, two clinical fellows) independently evaluated masses for mass-to-cortex corticomedullary attenuation ratio and heterogeneity score; these scores were used to derive the CT score by the previously proposed CT algorithm. The CT score's sensitivity, specificity, and PPV for ccRCC were calculated at threshold of ≥4, and NPV for ccRCC was calculated at threshold of ≥3 (consistent with thresholds in studies of the MRI-based clear-cell likelihood score and the CT algorithm's initial study). The CT score's sensitivity and specificity for papillary RCC were calculated at a threshold of ≤2. Interreader agreement was assessed using Gwet's AC1. Results: Overall, 61/97 (63%) masses were malignant; 44/97 (44%) were ccRCC. Across readers, CT score had sensitivity ranging from 47% to 95% [pooled sensitivity, 74% (95% CI, 68-80%)], specificity ranging from 19% to 83% [pooled specificity, 59% (95% CI, 52-67%)], PPV ranging from 48% to 76% [pooled PPV, 59% (95% CI, 49-71%)], and NPV ranging from 83% to 100% [pooled NPV, 90% (95% CI, 84-95%)], for ccRCC. CT score ≤2 had sensitivity ranging from 44% to 100% and specificity ranging from 77% to 98% for papillary RCC (representing 9/97 masses). Interreader agreement was substantial for attenuation score (AC1=0.70), poor for heterogeneity score (AC1=0.17), fair for 5-tiered CT score (AC1=0.32), and fair for dichotomous CT score at threshold of ≥4 (AC1=0.24; 95% CI, 0.14-0.33). Conclusion: The 5-tiered CT algorithm for evaluation of small solid renal masses was tested in an external sample and showed high NPV for ccRCC. Clinical Impact: The CT algorithm may be used for risk stratification and patient selection for active surveillance by identifying patients unlikely to have ccRCC.

    View details for DOI 10.2214/AJR.23.29151

    View details for PubMedID 37162037

  • Diagnostic performance of the "drooping" sign in CT diagnosis of exophytic renal angiomyolipoma. Abdominal radiology (New York) Shen, L., Nawaz, R., Tse, J. R., Negrete, L. M., Lubner, M. G., Toia, G. V., Liang, T., Wentland, A. L., Kamaya, A. 2023


    To evaluate the prevalence of angular interface and the "drooping" sign in exophytic renal angiomyolipomas (AMLs) and the diagnostic performance in differentiating exophytic lipid-poor AMLs from other solid renal masses.This IRB-approved, two-center study included 185 patients with 188 exophytic solid renal masses < 4 cm with histopathology and pre-operative CT within 30 days of surgical resection or biopsy. Images were reviewed for the presence of angular interface and the "drooping" sign qualitatively by three readers blinded to the final diagnosis, with majority rules applied. Both features were assessed quantitatively by cohort creators (who are not readers) independently. Free-marginal kappa was used to assess inter-reader agreement and agreement between two methods assessing each feature. Fisher's exact test, Mann-Whitney test, and multivariable logistic regression with two-tailed p < 0.05 were used to determine statistical significance. Diagnostic performance was assessed.Ninety-four patients had 96 AMLs, and 91 patients had 92 non-AMLs. Seventy-four (77%) of AMLs were lipid-poor based on quantitative assessment on CT. The presence of angular interface and the "drooping" sign by both qualitative and quantitative assessment were statistically significantly associated with AMLs (39% (qualitative) and 45% (quantitative) vs 15% (qualitative) and 13% (quantitative), and 48% (qualitative) and 43% (quantitative) vs 4% (qualitative) and 1% (quantitative), respectively, all p < 0.001) in univariable analysis. In multivariable analysis, only the "drooping" sign in either qualitative or quantitative assessment was a statistically significant predictor of AMLs (both p < 0.001). Inter-reader agreement for the "drooping" sign was moderate (k = 0.55) and for angular interface was fair (k = 0.33). Agreement between the two methods of assessing the "drooping" sign was substantial (k = 0.84) and of assessing the angular interface was moderate (k = 0.59). The "drooping" sign both qualitatively and quantitatively, alone or in combination of angular interface, had very high specificity (96-100%) and positive predictive value (PPV) (89-100%), moderate negative predictive value (62-68%), but limited sensitivity (23-49%) for lipid-poor AMLs.The "drooping" sign by both qualitative and quantitative assessment is highly specific for lipid-rich and lipid-poor AMLs. This feature alone or in combination with angular interface can aid in CT diagnosis of lipid-poor AMLs with very high specificity and PPV.

    View details for DOI 10.1007/s00261-023-03880-7

    View details for PubMedID 36947205

    View details for PubMedCentralID 4040184

  • Hepatocellular Adenomas: Molecular Basis and Multimodality Imaging Update. Radiographics : a review publication of the Radiological Society of North America, Inc Tse, J. R., Felker, E. R., Naini, B. V., Shen, L., Shen, J., Lu, D. S., Kamaya, A., Raman, S. S. 2023; 43 (3): e220134


    Hepatocellular adenomas (HCAs) are a family of liver tumors that are associated with variable prognoses. Since the initial description of these tumors, the classification of HCAs has expanded and now includes eight distinct genotypic subtypes based on molecular analysis findings. These genotypic subtypes have unique derangements in their cellular biologic makeup that determine their clinical course and may allow noninvasive identification of certain subtypes. Multiphasic MRI performed with hepatobiliary contrast agents remains the best method to noninvasively detect, characterize, and monitor HCAs. HCAs are generally hypointense during the hepatobiliary phase; the beta-catenin-mutated exon 3 subtype and up to a third of inflammatory HCAs are the exception to this characterization. It is important to understand the appearances of HCAs beyond their depictions at MRI, as these tumors are typically identified with other imaging modalities first. The two most feared related complications are bleeding and malignant transformation to hepatocellular carcinoma, although the risk of these complications depends on tumor size, subtype, and clinical factors. Elective surgical resection is recommended for HCAs that are persistently larger than 5 cm, adenomas of any size in men, and all beta-catenin-mutated exon 3 HCAs. Thermal ablation and transarterial embolization are potential alternatives to surgical resection. In the acute setting of a ruptured HCA, patients typically undergo transarterial embolization with or without delayed surgical resection. This update on HCAs includes a review of radiologic-pathologic correlations by subtype and imaging modality, related complications, and management recommendations. © RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

    View details for DOI 10.1148/rg.220134

    View details for PubMedID 36821508

  • Bosniak Classification, Version 2019 Class IIF: Follow-up Strategy Should be Revised. The Journal of urology Tse, J. R., Shen, L. 2023: 101097JU0000000000003365

    View details for DOI 10.1097/JU.0000000000003365

    View details for PubMedID 36787378

  • Editorial Comment: Meta-Analysis Supports ACR TI-RADS for Risk Stratification of Thyroid Nodules Over Other Systems. AJR. American journal of roentgenology Shen, L. 2023

    View details for DOI 10.2214/AJR.23.29094

    View details for PubMedID 36752372

  • Growth Kinetics of Pancreatic Neuroendocrine Neoplasms by Histopathologic Grade. Pancreas Cao, J. J., Shen, L., Visser, B. C., Yoon, L., Kamaya, A., Tse, J. R. 2023; 52 (2): e135-e143


    The aims of the study are to describe the growth kinetics of pathologically proven, treatment-naive pancreatic neuroendocrine neoplasms (panNENs) at imaging surveillance and to determine their association with histopathologic grade and Ki-67.This study included 100 panNENs from 95 patients who received pancreas protocol computed tomography or magnetic resonance imaging from January 2005 to July 2022. All masses were treatment-naive, had histopathologic correlation, and were imaged with at least 2 computed tomography or magnetic resonance imaging at least 90 days apart. Growth kinetics was assessed using linear and specific growth rate, stratified by grade and Ki-67. Masses were also assessed qualitatively to determine other possible imaging predictors of grade.There were 76 grade 1 masses, 17 grade 2 masses, and 7 grade 3 masses. Median (interquartile range) linear growth rates were 0.06 cm/y (0-0.20), 0.40 cm/y (0.22-1.06), and 2.70 cm/y (0.41-3.89) for grade 1, 2, and 3 masses, respectively (P < 0.001). Linear growth rate correlated with Ki-67 with r2 of 0.623 (P < 0.001). At multivariate analyses, linear growth rate was the only imaging feature significantly associated with grade (P = 0.009).Growth kinetics correlate with Ki-67 and grade. Grade 1 panNENs grow slowly versus grade 2-3 panNENs.

    View details for DOI 10.1097/MPA.0000000000002221

    View details for PubMedID 37523605

  • Diagnostic performance of hypoechoic perinephric fat as a predictor of prediabetes and diabetes. Abdominal radiology (New York) Shen, L., Tse, J. R., Negrete, L. M., Shon, A., Yoon, L., Liang, T., Kamaya, A. 2022


    To evaluate prevalence and predictive value of hypoechoic perinephric fat (HPF) in patients with prediabetes and diabetes compared to non-diabetics.Of 240 patients with renal ultrasound and hemoglobin A1c (HbA1c) measurements, 114 patients had either prediabetes (HbA1c 5.7-6.4%) or diabetes (HbA1c ≥ 6.5%), and 126 patients did not. Two radiologists (blinded to diagnosis) reviewed images and discrepancies were resolved by a third. Inter-reader agreement was compared using free-marginal kappa and intraclass correlation coefficient. Fisher's exact test, Mann-Whitney test, multivariable logistic regression, and Spearman's rank correlation test with two-tailed p < 0.05 were used to determine statistical significance.HPF was exclusively identified in prediabetic and diabetic patients with a prevalence of 23% (vs 0%; p < 0.001). Identification of HPF had almost perfect inter-reader agreement (k = 0.94) and was statistically significant (p = 0.034) while controlling for body mass index (BMI) and estimated glomerular filtration rate in multivariable analysis. HPF had extremely high specificity and positive predictive value (100% for both) in patients with prediabetes and diabetes although it was not a sensitive finding (23% sensitivity). In patients with prediabetes and diabetes, those with HPF were statistically significantly more likely to have chronic kidney disease (CKD) (p = 0.003). There was no statistically significant difference in BMI, stages of CKD, and types of diabetes.Hypoechoic perirenal fat has almost perfect inter-reader agreement and is highly specific for and predictive of prediabetes and diabetes. Its presence may also help identify those with chronic kidney disease among prediabetic and diabetic patients.

    View details for DOI 10.1007/s00261-022-03763-3

    View details for PubMedID 36480029

  • Outcomes of Bosniak Classification Version 2019 Class IIF Cystic Renal Masses at Imaging Surveillance. AJR. American journal of roentgenology Shen, L., Yoon, L., Chung, B. I., Kamaya, A., Tse, J. R. 2022


    Background: Bosniak classification system version 2019 (v2019) recommends that class IIF masses undergo follow-up imaging at 6 months, 12 months, and then annually for 5 years. The frequency and timing of upgrade on follow-up imaging are incompletely understood. Purpose: To describe the temporal evolution of Bosniak v2019 class IIF cystic renal masses, with attention to outcomes at 6-month follow-up, time to class upgrade, and malignant histologic diagnoses. Methods: This retrospective study included 219 patients (91 women, 128 men; median age, 72 years) with 246 localized class IIF masses from January 2005 to June 2022. Patients underwent both a baseline and at least one follow-up renal-mass protocol contrast-enhanced CT or MRI. Two radiologists evaluated masses at all follow-up time points to categorize masses as downgraded (class I or II), stable (localized class IIF), or upgraded (class III or IV, solid, or ≥T3a, N1, or M1 disease); a third radiologist resolved discrepancies. Incidence rate of upgrade was determined. Histopathologic outcomes were assessed for resected masses. Results: Median follow-up was 28.4 months (IQR, 13.7-59.4 months). At 6-month follow-up, 5 (2%) masses were downgraded, 241 (98%) were stable, and none were upgraded. Based on final follow-up, 14 (6%) masses were downgraded, 223 (91%) were stable, and 9 (4%) were upgraded. All upgrade events entailed a class increase to III (n=7) or IV (n=2); no mass became solid or developed T3, N1, or M1 disease. Among the nine upgraded masses, median time to upgrade was 53.5 months (IQR, 23.2-63.7 months). Incidence rate of upgrade was 3.006 per 100,000 person-days (95% CI, 1.466-5.516). Ten masses were resected; histopathology was benign in six, and malignant in four. Of the four malignant masses, one was upgraded to class III after 15 months of preoperative follow-up imaging, and three remained class IIF on preoperative follow-up imaging. No resected malignant mass developed postoperative recurrence. Conclusion: Bosniak v2019 class IIF masses are unlikely to represent aggressive malignancy; only 4% were upgraded over time, and never on initial 6-month follow-up. Clinical Impact: The currently recommended initial 6-month follow-up imaging examination for class IIF masses is of questionable clinical utility.

    View details for DOI 10.2214/AJR.22.28599

    View details for PubMedID 36416398

  • Differentiation of benign from malignant solid renal lesions using CT-based radiomics and machine learning: comparison with radiologist interpretation. Abdominal radiology (New York) Wentland, A. L., Yamashita, R., Kino, A., Pandit, P., Shen, L., Brooke Jeffrey, R., Rubin, D., Kamaya, A. 2022


    PURPOSE: To assess the performance of a machine learning model trained with contrast-enhanced CT-based radiomics features in distinguishing benign from malignant solid renal masses and to compare model performance with three abdominal radiologists.METHODS: Patients who underwent intra-operative ultrasound during a partial nephrectomy were identified within our institutional database, and those who had pre-operative contrast-enhanced CT examinations were selected. The renal masses were segmented from the CT images and radiomics features were derived from the segmentations. The pathology of each mass was identified; masses were labeled as either benign [oncocytoma or angiomyolipoma (AML)] or malignant [clear cell, papillary, or chromophobe renal cell carcinoma (RCC)] depending on the pathology. The data were parsed into a 70/30 train/test split and a random forest machine learning model was developed to distinguish benign from malignant lesions. Three radiologists assessed the cohort of masses and labeled cases as benign or malignant.RESULTS: 148 masses were identified from the cohort, including 50 benign lesions (23 AMLs, 27 oncocytomas) and 98 malignant lesions (23 clear cell RCC, 44 papillary RCC, and 31 chromophobe RCCs). The machine learning algorithm yielded an overall accuracy of 0.82 for distinguishing benign from malignant lesions, with an area under the receiver operating curve of 0.80. In comparison, the three radiologists had significantly lower accuracies (p=0.02) ranging from 0.67 to 0.75.CONCLUSION: A machine learning model trained with CT-based radiomics features can provide superior accuracy for distinguishing benign from malignant solid renal masses compared to abdominal radiologists.

    View details for DOI 10.1007/s00261-022-03735-7

    View details for PubMedID 36370180

  • I saw the "bear paw" sign - Massive renal xanthogranulomatous pyelonephritis. Clinical imaging Mynarski, N. J., Shen, L., Negrete, L. M. 2022; 93: 70-74


    The bear paw sign is a radiologic sign seen on computed tomography (CT) that indicates the development of xanthogranulomatous pyelonephritis (XGP). It refers to the multiple, rim-enhancing, low attenuation renal collections seen in the diffuse form of XGP. The term "bear paw" sign first appeared in the literature in 1989 and has since been widely used to describe this serious, but treatable, pathology.

    View details for DOI 10.1016/j.clinimag.2022.11.006

    View details for PubMedID 36410078

  • Positive predictive value of LI-RADS US-3 observations: multivariable analysis of clinical and imaging features. Abdominal radiology (New York) Tse, J. R., Shen, L., Tiyarattanachai, T., Bird, K. N., Liang, T., Yoon, L., Kamaya, A. 2022


    PURPOSE: To determine how clinical and imaging features affect the positive predictive values (PPV) of US-3 observations.METHODS: In this retrospective study, 10,546 adult patients who were high risk for hepatocellular carcinoma (HCC) from 2017 to 2021 underwent ultrasound screening/surveillance. Of these, 225 adult patients (100 women, 125 men) with an US-3 observation underwent diagnostic characterization with multiphasic CT (93; 41%), MRI (130; 58%), or contrast-enhanced ultrasound (2; 1%). US-3 observations included focal observations≥10mm in 216 patients and new venous thrombi in 9 patients. PPV with 95% confidence intervals were calculated using diagnostic characterization as the reference standard. Multivariable analysis of clinical and imaging features was performed to determine the strongest associations with cancer.RESULTS: Overall PPV for an US-3 observationwas 33% (27-39%) for at least intermediate probability of cancer (≥LR-3) and 15% (10-20%) for at least probable cancer (≥LR-4). At multivariable analysis, cirrhosis had the strongest effect size for at least probable cancer (p<0.001; odds ratio OR 20.4), followed by observation size (p<0.001; OR 2.65) and age (p=0.004; OR 1.05). Alpha-fetoprotein, visualization score, and observation echogenicity were not statistically significant associations. Modality (MRI versus CT) did not affect PPV. Due to the large effect of cirrhosis, PPV was then stratified by the presence (n=116; 52%) or absence (n=109; 48%) of cirrhosis. For at least probable cancer (≥LR-4), PPV increased from 4% (0-7%; non-cirrhotic) to 26% (18-34%; p<0.001; cirrhosis).CONCLUSION: Cirrhosis most strongly affects PPV of US-3 observations for at least probable cancer at diagnostic characterization among high-risk patients, increasing to 1 in 4 among cirrhotic patients from 1 in 25 among non-cirrhotic patients.

    View details for DOI 10.1007/s00261-022-03681-4

    View details for PubMedID 36253490

  • Predictive value and prevalence of refractive edge shadow in diagnosis of ovarian dermoids. Abdominal radiology (New York) Shen, L., Tse, J. R., Negrete, L. M., Lo, E., Yoon, L., Kamaya, A. 2022


    To evaluate the diagnostic performance of refractive edge shadow in evaluation of ovarian dermoids compared to other benign adnexal masses.Ultrasound images of 139 patients with 154 dermoids, endometriomas, and hemorrhagic cysts were retrospectively reviewed by 3 radiologists blinded to final diagnosis. Ultrasound and clinical features were compared to pathology or follow-up ultrasound results as reference standard. Inter-reader agreements with free-marginal kappa and diagnostic performance were evaluated. The former was compared using Fisher's exact test or Mann-Whitney test with p < 0.05 to determine statistical significance.The study sample consisted of 154 lesions: 50 dermoids, 50 endometriomas, and 54 hemorrhagic cysts. Refractive edge shadow, homogeneous echogenic appearance, tip of the iceberg sign, mural echogenic nodule, echogenic shadowing focus, and dot-dash sign all were statistically significant across all readers for the diagnosis of dermoid. Prevalence of each feature in dermoids compared to other entities were as follows: refractive edge shadow (70% vs 8%; p < 0.001), homogeneously echogenic appearance (34% vs 2%; p < 0.001), tip of the iceberg sign (16% vs 1%; p < 0.001), mural echogenic nodule (38% vs 2%; p < 0.001), echogenic shadowing focus (13% vs 1%; p < 0.001), and dot-dash sign (44% vs 1%; p < 0.001). Refractive edge shadow had the highest sensitivity, negative predictive value, and accuracy among all ultrasound features associated with dermoids (70%, 86%, and 85%, respectively).Refractive edge shadow is a promising ultrasound feature for diagnosis of dermoids, with the highest diagnostic accuracy and prevalence compared to other previously described features associated with dermoids.

    View details for DOI 10.1007/s00261-022-03666-3

    View details for PubMedID 36098759

  • Clinical and ultrasound features of dermoid-associated adnexal torsion. Abdominal radiology (New York) Shen, L., Tse, J. R., Negrete, L. M., Flory, M. N., Yoon, L., Kamaya, A. 2022


    To determine the clinical and ultrasound features of dermoid-associated adnexal torsion.Forty-four patients with at least one dermoid and ultrasound ≤ 30 days of surgery were retrospectively reviewed by three radiologists. Ultrasound and clinical findings were compared to intra-operative findings using Fisher's exact test or Mann-Whitney test with p < 0.05 to determine statistical significance.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.Correct. No edit RESULTS: Twenty patients had torsion, while 24 patients did not. Patients with dermoid-associated torsion were more likely to present to emergency department (ED) (100% vs 13%; p < 0.001) and have acute unilateral pelvic pain (100% vs 42%; p < 0.001). On ultrasound, patients with torsion had larger dermoids (median largest dimension 9.0 cm (IQR 7.7-11.1) vs 6.0 cm (IQR 4.4-7.5); p < 0.001), displaced dermoid anterior or superior to the uterus (59% vs 21%; p = 0.016), and ipsilateral adnexal fluid (41% vs 4%; p = 0.003). Displaced dermoid and ipsilateral adnexal fluid had substantial (kappa = 0.72) and moderate inter-rater agreement (kappa = 0.49), respectively. The combination of ED presentation and each statistically significant ultrasound feature (dermoid size ≥ 5.0 cm, displaced dermoid, and ipsilateral adnexal fluid) yielded high specificity and positive predictive value (ranging from 93-100% to 92-100%, respectively). The combination of ED presentation and dermoid size ≥ 5.0 cm yielded the highest sensitivity, negative predicative value, and accuracy (100%, 100%, and 96%, respectively).Please check and confirm whether the edit made to the article title is in order.Looks great. No edits. Thank you!Although the diagnosis of adnexal torsion in the presence of an ovarian dermoid is traditionally challenging, the combination of ED presentation and ultrasound features increase diagnostic confidence of dermoid-associated adnexal torsion.

    View details for DOI 10.1007/s00261-022-03601-6

    View details for PubMedID 35809127

  • Interobserver agreement between eight observers using IOTA simple rules and O-RADS lexicon descriptors for adnexal masses. Abdominal radiology (New York) Antil, N., Raghu, P. R., Shen, L., Tiyarattanachai, T., Chang, E. M., Ferguson, C. W., Ho, A. A., Lutz, A. M., Mariano, A. J., Morimoto, L. N., Kamaya, A. 2022


    PURPOSE: To evaluate interobserver agreement in assigning imaging features and classifying adnexal masses using the IOTA simple rules versus O-RADS lexicon and identify causes of discrepancy.METHODS: Pelvic ultrasound (US) examinations in 114 women with 118 adnexal masses were evaluated by eight radiologists blinded to the final diagnosis (4 attendings and 4 fellows) using IOTA simple rules and O-RADS lexicon. Each feature category was analyzed for interobserver agreement using intraclass correlation coefficient (ICC) for ordinal variables and free marginal kappa for nominal variables. The two-tailed significance level (a) was set at 0.05.RESULTS: For IOTA simple rules, interobserver agreement was almost perfect for three malignant lesion categories (M2-4) and substantial for the remaining two (M1, M5) with k-values of 0.80-0.82 and 0.68-0.69, respectively. Interobserver agreement was almost perfect for two benign feature categories (B2, B3), substantial for two (B4, B5) and moderate for one (B1) with k-values of 0.81-0.90, 0.69-0.70 and 0.60, respectively. For O-RADS, interobserver agreement was almost perfect for two out of ten feature categories (ascites and peritoneal nodules) with k-values of 0.89 and 0.97. Interobserver agreement ranged from fair to substantial for the remaining eight feature categories with k-values of 0.39-0.61. Fellows and attendings had ICC values of 0.725 and 0.517, respectively.CONCLUSION: O-RADS had variable interobserver agreement with overall good agreement. IOTA simple rules had more uniform interobserver agreement with overall excellent agreement. Greater reader experience did not improve interobserver agreement with O-RADS.

    View details for DOI 10.1007/s00261-022-03580-8

    View details for PubMedID 35763052

  • Outcomes of LI-RADS US-2 Subthreshold Observations Detected on Surveillance Ultrasound. AJR. American journal of roentgenology Tse, J. R., Shen, L., Bird, K. N., Yoon, L., Kamaya, A. 2022


    Background: Ultrasound LI-RADS version 2017 recommends that patients with US-2 subthreshold observations undergo repeat surveillance ultrasound in 3-6 months and return to routine surveillance if the observation shows no growth for 2 years. However, outcomes of US-2 observations are unknown. Objective: To determine imaging outcomes of US-2 observations detected on surveillance ultrasound examinations. Methods: This retrospective study included 175 patients (median age, 59 years; 70 women, 105 men) at high risk for hepatocellular carcinoma (HCC) with US-2 observations (i.e., subcentimeter observations) on surveillance ultrasound. Observations were classified on ≥2-year follow-up ultrasound as showing no correlate, stable (if remaining subcentimeter), or progressed (if measuring ≥10 mm, meeting US-3 criteria). Observations were classified on follow-up multiphasic CT or MR (stratified as <2-year vs ≥2-year follow-up) as showing no correlate or, if showing a correlate, using CT/MRI LI-RADS version 2018. Results: A total of 111 patients had ≥2-year follow-up ultrasound and 106 had follow-up CT or MRI (79 before 2 years, 27 after 2 years). Based on final follow-up examinations, 173/175 observations were stable on ≥2-year follow-up ultrasound (n=68); showed no correlate on follow-up ultrasound, CT, or MRI (n=88); or were classified as LR-1 or LR-2 on CT or MRI (n=17). The remaining 2/175 observations were LR-3 on CT or MRI. No observations progressed to US-3 on follow-up ultrasound or were classified as ≥LR-4 on CT or MRI. A correlate was observed in 25 of the 106 follow-up CT or MRI examinations, (LR-1 or LR-2 in 23; LR-3 in 2). Eight patients developed HCC at a median of 2.0 years after initial US-2 observation detection; all HCCs were in separate locations from the baseline observations and were preceded by a surveillance ultrasound that could not re-identify the baseline observation. In three patients who underwent liver transplant, the explant showed no dysplastic nodule or HCC. Conclusion: US-2 subthreshold observations are unlikely to progress or become HCC and commonly have no correlate on follow-up imaging. Clinical Impact: Because of the low progression rate of US-2 subthreshold observations, it is unclear if an extended period of intensive surveillance, as recommended by multiple professional societies, is warranted.

    View details for DOI 10.2214/AJR.22.27812

    View details for PubMedID 35703411

  • Nyquist sampling theorem and Bosniak classification, version 2019: effect of thin axial sections on categorization and agreement. European radiology Tse, J. R., Shen, L., Shen, J., Yoon, L., Kamaya, A. 2022


    To determine if CT axial images reconstructed at current standard of care (SOC; 2.5-3 mm) or thin (≤ 1 mm) sections affect categorization and inter-rater agreement of cystic renal masses assessed with Bosniak classification, version 2019.In this retrospective single-center study, 3 abdominal radiologists reviewed 131 consecutive cystic renal masses from 100 patients performed with CT renal mass protocol from 2015 to 2021. Images were reviewed in two sessions: first with SOC and then the addition of thin sections. Individual and overall categorizations are reported, latter of which is based on majority opinion with 3-way discrepancies resolved by a fourth reader. Major categorization changes were defined as differences between classes I-II, IIF, or III-IV.Thin sections led to a statistically significant major category change with class II for all readers individually (p = 0.004-0.041; McNemar test), upgrading 10-17% of class II masses, most commonly to class IIF followed by III. Modal reason for upgrades was due to identification of additional septa followed by larger measurement of enhancing features. Masses categorized as class I, III, or IV on SOC sections were unaffected, as were identification of protrusions. Inter-rater agreements using weighted Cohen's kappa were 0.679 for SOC and 0.691 for thin sections (both substantial).Thin axial sections upgraded up to one in six class II masses to IIF or III through identification of additional septa or larger feature. Other classes, including III-IV, were unaffected. Inter-rater agreements were substantial regardless of section thickness.• Thin axial sections (≤ 1 mm) compared to standard of care sections (2.5-3 mm) led to identification of additional septa but did not affect identification of protrusions. • Thin axial sections (≤ 1 mm) compared to standard of care sections (2.5-3 mm) can upgrade a small proportion of cystic renal masses from class II to IIF or III when applying Bosniak classification, version 2019. • Inter-rater agreements were substantial regardless of section thickness.

    View details for DOI 10.1007/s00330-022-08876-3

    View details for PubMedID 35705828

  • Safety of percutaneous, image-guided biopsy of hepatocellular carcinoma with and without concurrent ablation. Abdominal radiology (New York) Tse, J. R., Terashima, K., Shen, L., McWilliams, J. P., Lu, D. S., Raman, S. S. 2022


    PURPOSE: To determine the prevalence of adverse events after image-guided biopsy of histologically proven hepatocellular carcinomas (HCC) using a standardized, indirect access, coaxial biopsy technique.METHODS: In this IRB-approved, HIPAA compliant, and retrospective study, we evaluated all consecutive adult patients from 2011 to 2016 who underwent image-guided biopsy of HCC with and without concurrent ablation. Tumor seeding was defined as any new lesion along the needle tract on subsequent imaging. Adverse events were graded using both the Clavien-Dindo Complication Classification system and the most recently proposed Society of Interventional Radiology (SIR) Adverse Event Classification System.RESULTS: A total of 383 patients underwent 398 biopsies (64±11years; 112 women, 271 men). Most patients (282; 71%) underwent concurrent ablation. Adverse events occurred after 18 biopsies (4.5%): 13 were Grade I (Clavien-Dindo) or minor (SIR) and included hematoma (7), hepatic vein thrombus (2), portal vein thrombus (2), moderate pleural effusion (1), and small pneumothorax (1). The remaining 5 (1.3%) adverse events were classified as Grade II-IIIa (Clavien-Dindo) or moderate (SIR) and included hematoma requiring blood products (n=1), arrhythmia (n=1), and symptomatic pleural effusions requiring treatment (n=3). Baseline age, sex, cause of liver disease, HCC diameter, and HCC grade were not associated with adverse events. There were no tumor seeding events after a median follow-up of 611days (interquartile range of 211-1104).CONCLUSION: Percutaneous image-guided tissue sampling using a standardized, indirect access, coaxial technique can be performed safely with and without concurrent ablation by trained cross-sectional interventional radiologists at a tertiary liver transplant center.

    View details for DOI 10.1007/s00261-022-03494-5

    View details for PubMedID 35396970

  • Growth kinetics and progression rates of cystic renal masses on active surveillance. Tse, J., Shen, L., Yoon, L., Kamaya, A. LIPPINCOTT WILLIAMS & WILKINS. 2022
  • Evaluation of early sonographic predictors of gangrenous cholecystitis: mucosal discontinuity and echogenic pericholecystic fat. Abdominal radiology (New York) Tse, J. R., Gologorsky, R., Shen, L., Bingham, D. B., Jeffrey, R. B., Kamaya, A. 1800


    PURPOSE: To identify early sonographic features of gangrenous cholecystitis.MATERIALS AND METHODS: 101 patients with acute cholecystitis and a pre-operative sonogram were retrospectively reviewed by three radiologists in this IRB-approved and HIPAA-compliant study. Imaging data were correlated with histologic findings and compared using the Fisher's exact test or Student t test with p<0.05 to determine statistical significance.RESULTS: Forty-eight patients had gangrenous cholecystitis and 53 had non-gangrenous acute cholecystitis. Patients with gangrenous cholecystitis tended to be older (67±17 vs 48±18years; p=0.0001), male (ratio of male:female 2:1 vs 0.6:1; p=0.005), tachycardic (60% vs 28%; p=0.001), and diabetic (25% vs 8%; p=0.001). Median time between pre-operative sonogram and surgery was 1day. On imaging, patients with gangrenous cholecystitis were more likely to have echogenic pericholecystic fat (p=0.001), mucosal discontinuity (p=0.010), and frank perforation (p=0.004), while no statistically significant differences were seen in the presence of sloughed mucosa (p=0.104), pericholecystic fluid (p=0.523) or wall striations (p=0.839). In patients with gangrenous cholecystitis and echogenic pericholecystic fat, a smaller subset had concurrent mucosal discontinuity (57%), and a smaller subset of those had concurrent frank perforation (58%). The positive likelihood ratios for gangrenous cholecystitis with echogenic fat and mucosal discontinuity were 4.6 (95% confidence interval 1.9-11.3) and 14.4 (2.0-106), respectively.CONCLUSION: Echogenic pericholecystic fat and mucosal discontinuity are early sonographic findings that may help identify gangrenous cholecystitis prior to late findings of frank perforation.

    View details for DOI 10.1007/s00261-021-03320-4

    View details for PubMedID 34985635

  • Growth Kinetics and Progression Rate of Bosniak Classification, Version 2019 III and IV Cystic Renal Masses on Imaging Surveillance. AJR. American journal of roentgenology Tse, J. R., Shen, L., Shen, J., Yoon, L., Chung, B. I., Kamaya, A. 2022


    Background: Active surveillance is increasingly used as first-line management for localized renal masses. Triggers for intervention primarily reflect growth kinetics, which are poorly investigated for cystic masses defined by Bosniak classification version 2019 (v2019). Objective: To determine growth kinetics and incidence rates of progression of class III and IV cystic renal masses, as defined by Bosniak classification v2019. Methods: This retrospective study included 105 patients (68 men, 37 women; median age, 67 years) with 112 Bosniak v2019 class III or IV cystic renal masses on baseline renal-mass protocol CT or MRI examinations from January 2005 to September 2021. Mass dimensions were measured. Progression was defined as any of: linear growth rate (LGR) ≥5 mm per year (representing clinical guideline threshold for intervention), volume doubling time <1 year, T category increase, or N1 or M1 disease. Class III and IV masses were compared. Time-to-progression was estimated using Kaplan-Meier curve analysis. Results: At baseline, 58 masses were class III and 54 were class IV. Median follow-up was 406 days. Median LGR was for class III masses 0.0 mm per year [interquartile range (IQR) -1.3 to 1.8] and for class IV masses 2.3 mm per year (IQR 0.0¬¬-5.7) (p<.001). LGR exceeded 5 mm per year in 4 (7%) class 3 masses and 15 (28%) class IV masses (p=.005). Two patients, both with class IV masses, developed distant metastases. Incidence rate of progression was for class III masses 11.0 (95% CI 4.5-22.8) and for class IV masses 73.6 (95% CI 47.8-108.7) per 100,000 person-days of follow-up. Median time-to-progression was undefined for class III mases given small number of progression events and 710 days for class IV masses. Hazard ratio of progression for class IV relative to class III masses was 5.1 (95% CI 2.5-10.8) (p<.001). Conclusion: During active surveillance of cystic masses evaluated using Bosniak classification v2019, class IV masses grew faster and were more likely to progress than class III masses. Clinical Impact: In comparison with current active surveillance guidelines that treat class III and IV masses similarly, future iterations may incorporate relatively more intensive surveillance for class IV masses.

    View details for DOI 10.2214/AJR.22.27400

    View details for PubMedID 35293234

  • Inflammatory pseudotumor-like follicular dendritic cell tumor of the spleen: a case report and approach to differential diagnosis. Radiology case reports Nguyen, A., Negrete, L. M., Bulterys, P. L., Shen, L. 2021; 16 (11): 3213-3216


    We present a case of an inflammatory pseudotumor-like follicular dendritic cell tumor of the spleen. The patient is a 44-year-old woman, without significant underlying history, who presented with nonspecific abdominal pain for a few months. Both a contrast enhanced computed tomography and magnetic resonance imaging revealed a new 2.5 cm enhancing splenic lesion, which demonstrated hypermetabolic activity on subsequent positron emission tomography and computed tomography scan. Since the lesion was new compared to more remote imaging and hypermetabolic, a splenectomy was performed. Pathology confirmed the diagnosis and demonstrated positivity for Epstein-Barr Virus .

    View details for DOI 10.1016/j.radcr.2021.07.078

    View details for PubMedID 34484521

  • Prevalence of Malignancy and Histopathologic Association of Bosniak Classification, Version 2019 Class III and IV Cystic Renal Masses. The Journal of urology Tse, J. R., Shen, L., Shen, J., Yoon, L., Kamaya, A. 2020: 101097JU0000000000001438


    PURPOSE: Bosniak Classification, version 2019 (v2019) describes two types of class III and IV masses each: 1) thick, wall/septa ≥4 mm (III-WS), 2) obtuse protrusion ≤3 mm (III-OP), 3) obtuse protrusion ≥4 mm (IV-OP), and 4) acute protrusion of any size (IV-AP). The purposes were to determine the prevalence of malignancy and histopathologic features of class III and IV masses and subclasses.MATERIALS AND METHODS: In this IRB-approved and HIPAA-compliant study, three fellowship-trained abdominal radiologists (R1-3) reviewed cystic renal masses that had tissue pathology and pre-operative renal mass protocol CT or MRI. Classes based on v2019 and prior classification systems were retrospectively re-assigned and associated with malignancy, aggressive histologic features (necrosis or high Fuhrman grade), and radiologic progression following resection.RESULTS: The final sample included 79 masses (59 malignant, 20 benign) from 74 patients. Based on v2019, prevalence of malignancy ranged from 56-61% (mean 60%) for class III and 83-83% (mean 83%) for class IV (p=0.036, 0.013, 0.036 for R1-3). Prevalence of malignancy within subclasses were: III-WS (47-53%); III-OP (71-85%); IV-OP (75-87%); IV-AP (87-95%; p=0.029, 0.001, 0.005). All readers were more likely to classify malignancies with aggressive histologic features as class IV (88-100%) rather than class III (0-12%; p=0.012, <0.001, 0.002), corresponding to a negative predictive value of 96-100%. Following treatment (mean follow-up length 1210 days), one patient developed metastases.CONCLUSIONS: Bosniak Classification, version 2019 can help risk stratification of class III-IV masses by identifying those likely to be malignant and have aggressive histologic features.

    View details for DOI 10.1097/JU.0000000000001438

    View details for PubMedID 33085925

  • Bosniak Classification of Cystic Renal Masses Version 2019: Comparison of Categorization using CT and MRI. AJR. American journal of roentgenology Tse, J. R., Shen, J. n., Shen, L. n., Yoon, L. n., Kamaya, A. n. 2020


    Please see the Author Video associated with this article. Background: Bosniak Classification, version 2019 recently proposed refinements for cystic renal mass characterization and now formally incorporates MRI, which may improve concordance with CT. Purpose: To compare concordance of CT and MRI in evaluation of cystic renal masses using Bosniak Classification, version 2019. Materials and Methods: In this IRB-approved and HIPAA compliant study, three abdominal radiologists (R1-R3) retrospectively reviewed 68 consecutive cystic renal masses from 45 patients assessed with both CT and MR renal mass protocols within a year between 2005-2019. CT and MRI were reviewed independently and in separate sessions, using both the original and version 2019 Bosniak Classification systems. Results: Using Bosniak Classification, version 2019, cystic renal masses were classified into 12 category I, 19 category II, 13 category IIF, 4 category III, and 20 category IV by CT and 8 category I, 15 category II, 23 category IIF, 9 category III, and 13 category IV by MRI. Among individual features, MRI depicted more septa (p<0.001, p=0.046, p=0.005 for R1-R3; McNemar's test) for all radiologists, though both CT and MRI showed a similar number of protrusions (p=0.823, 1.0, 0.302) and maximal septa/wall thickness (p=1.0, 1.0, 0.145). Of discordant cases with version 2019, MRI led to the higher category in 12 masses. Reason for upgrade was most commonly due to protrusions identified only on MRI (n=4), increased number of septa (n=3), and a new category of heterogeneously T1-hyperintense (n=3). Neither modality was more likely to lead to a category change for both version 2019 (p=0.502; McNemar's test) and the original Bosniak classification system (p=0.823). Overall inter-rater agreement was substantial for both CT (κ=0.745) and MRI (κ=0.655) using version 2019 and was slightly higher than that of the original system (CT κ=0.707; MRI κ=0.623). Conclusion: CT and MRI were concordant in the majority of cases using Bosniak Classification, version 2019 and category changes by modality were not statistically significant. Inter-rater agreements were substantial for both CT and MRI. Clinical Impact: Bosniak Classification, version 2019 applied to cystic renal masses has substantial inter-rater agreement and does not lead to systematic category upgrades with either CT or MRI.

    View details for DOI 10.2214/AJR.20.23656

    View details for PubMedID 32755181

  • Human-machine partnership with artificial intelligence for chest radiograph diagnosis. NPJ digital medicine Patel, B. N., Rosenberg, L. n., Willcox, G. n., Baltaxe, D. n., Lyons, M. n., Irvin, J. n., Rajpurkar, P. n., Amrhein, T. n., Gupta, R. n., Halabi, S. n., Langlotz, C. n., Lo, E. n., Mammarappallil, J. n., Mariano, A. J., Riley, G. n., Seekins, J. n., Shen, L. n., Zucker, E. n., Lungren, M. n. 2019; 2: 111


    Human-in-the-loop (HITL) AI may enable an ideal symbiosis of human experts and AI models, harnessing the advantages of both while at the same time overcoming their respective limitations. The purpose of this study was to investigate a novel collective intelligence technology designed to amplify the diagnostic accuracy of networked human groups by forming real-time systems modeled on biological swarms. Using small groups of radiologists, the swarm-based technology was applied to the diagnosis of pneumonia on chest radiographs and compared against human experts alone, as well as two state-of-the-art deep learning AI models. Our work demonstrates that both the swarm-based technology and deep-learning technology achieved superior diagnostic accuracy than the human experts alone. Our work further demonstrates that when used in combination, the swarm-based technology and deep-learning technology outperformed either method alone. The superior diagnostic accuracy of the combined HITL AI solution compared to radiologists and AI alone has broad implications for the surging clinical AI deployment and implementation strategies in future practice.

    View details for DOI 10.1038/s41746-019-0189-7

    View details for PubMedID 31754637

    View details for PubMedCentralID PMC6861262

  • Erratum: Author Correction: Human-machine partnership with artificial intelligence for chest radiograph diagnosis. NPJ digital medicine Patel, B. N., Rosenberg, L. n., Willcox, G. n., Baltaxe, D. n., Lyons, M. n., Irvin, J. n., Rajpurkar, P. n., Amrhein, T. n., Gupta, R. n., Halabi, S. n., Langlotz, C. n., Lo, E. n., Mammarappallil, J. n., Mariano, A. J., Riley, G. n., Seekins, J. n., Shen, L. n., Zucker, E. n., Lungren, M. P. 2019; 2: 129


    [This corrects the article DOI: 10.1038/s41746-019-0189-7.].

    View details for DOI 10.1038/s41746-019-0198-6

    View details for PubMedID 31840097

    View details for PubMedCentralID PMC6904441

  • Author Correction: Human-machine partnership with artificial intelligence for chest radiograph diagnosis. NPJ digital medicine Patel, B. N., Rosenberg, L. n., Willcox, G. n., Baltaxe, D. n., Lyons, M. n., Irvin, J. n., Rajpurkar, P. n., Amrhein, T. n., Gupta, R. n., Halabi, S. n., Langlotz, C. n., Lo, E. n., Mammarappallil, J. n., Mariano, A. J., Riley, G. n., Seekins, J. n., Shen, L. n., Zucker, E. n., Lungren, M. P. 2019; 2 (1): 129


    An amendment to this paper has been published and can be accessed via a link at the top of the paper.

    View details for DOI 10.1038/s41746-019-0198-6

    View details for PubMedID 33293693

  • Translabial US: Preoperative Detection of Midurethral Sling Erosion in Stress Urinary Incontinence. Radiology Viragh, K. A., Cohen, S. A., Shen, L., Kurzbard-Roach, N., Raz, S., Raman, S. S. 2018; 289 (3): 721-727


    Purpose To evaluate the performance of translabial (TL) US in preoperative detection of sling erosion into pelvic organs with cystourethroscopic and surgical correlation. Materials and Methods The study cohort included women who underwent surgery at a subspecialty center (from 2008 to 2016) for suspected mesh complications in the setting of previous midurethral sling placement for stress urinary incontinence (from 1999 to 2012) with available preoperative TL US imaging. Clinical information, the finding of sling erosion identified intraoperatively and at cystourethroscopy, and blinded dual-reader radiologic analysis of the TL US studies for mesh location (intraluminal, mural, or extramural) relative to pelvic organs (bladder, urethra, vagina, or rectum) were evaluated. The diagnostic performance of TL US was correlated with the reference standard of surgical findings. The consensus of two radiologists was recorded, and interobserver agreement was evaluated with the κ statistic. Results Of the 124 women who were suspected of having sling erosion (mean age, 57.5 years ± 11.1 [standard deviation]), 15 women (12.1%) had sling erosion into the urethra or bladder at surgery. Sensitivity and specificity for erosion at TL US were 53% (95% confidence interval: 45%, 62%) and 100% (95% confidence interval: 97%, 100%), respectively, when erosion was defined as only intraluminal mesh products. Sensitivity and specificity for erosion at TL US were 93% (95% confidence interval: 89%, 98%) and 72% (95% confidence interval: 65%, 80%), respectively, when erosion was defined as visualizing either intraluminal or intramural mesh products. Interobserver agreement (κ value) was 0.95. Cystourethroscopy had 67% sensitivity and 100% specificity for sling erosion. Conclusion Preoperative translabial US can be used to detect sling erosion into the lower urinary tract, with sensitivity up to 93% and specificity up to 100%. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Benson and Phillips in this issue.

    View details for DOI 10.1148/radiol.2018180786

    View details for PubMedID 30106346

  • Pathological and 3 Tesla Volumetric Magnetic Resonance Imaging Predictors of Biochemical Recurrence after Robotic Assisted Radical Prostatectomy: Correlation with Whole Mount Histopathology. The Journal of urology Tan, N., Shen, L., Khoshnoodi, P., Alcalá, H. E., Yu, W., Hsu, W., Reiter, R. E., Lu, D. Y., Raman, S. S. 2018; 199 (5): 1218-1223


    We sought to identify the clinical and magnetic resonance imaging variables predictive of biochemical recurrence after robotic assisted radical prostatectomy in patients who underwent multiparametric 3 Tesla prostate magnetic resonance imaging.We performed an institutional review board approved, HIPAA (Health Insurance Portability and Accountability Act) compliant, single arm observational study of 3 Tesla multiparametric magnetic resonance imaging prior to robotic assisted radical prostatectomy from December 2009 to March 2016. Clinical, magnetic resonance imaging and pathological information, and clinical outcomes were compiled. Biochemical recurrence was defined as prostate specific antigen 0.2 ng/cc or greater. Univariate and multivariate regression analysis was performed.Biochemical recurrence had developed in 62 of the 255 men (24.3%) included in the study at a median followup of 23.5 months. Compared to the subcohort without biochemical recurrence the subcohort with biochemical recurrence had a greater proportion of patients with a high grade biopsy Gleason score, higher preoperative prostate specific antigen (7.4 vs 5.6 ng/ml), intermediate and high D'Amico classifications, larger tumor volume on magnetic resonance imaging (0.66 vs 0.30 ml), higher PI-RADS® (Prostate Imaging-Reporting and Data System) version 2 category lesions, a greater proportion of intermediate and high grade radical prostatectomy Gleason score lesions, higher pathological T3 stage (all p <0.01) and a higher positive surgical margin rate (19.3% vs 7.8%, p = 0.016). On multivariable analysis only tumor volume on magnetic resonance imaging (adjusted OR 1.57, p = 0.016), pathological T stage (adjusted OR 2.26, p = 0.02), positive surgical margin (adjusted OR 5.0, p = 0.004) and radical prostatectomy Gleason score (adjusted OR 2.29, p = 0.004) predicted biochemical recurrence.In this cohort tumor volume on magnetic resonance imaging and pathological variables, including Gleason score, staging and positive surgical margins, significantly predicted biochemical recurrence. This suggests an important new imaging biomarker.

    View details for DOI 10.1016/j.juro.2017.10.042

    View details for PubMedID 29128577

    View details for PubMedCentralID PMC6946378

  • Automatic Classification of Ultrasound Screening Examinations of the Abdominal Aorta. Journal of digital imaging Morioka, C., Meng, F., Taira, R., Sayre, J., Zimmerman, P., Ishimitsu, D., Huang, J., Shen, L., El-Saden, S. 2016; 29 (6): 742-748


    Our work facilitates the identification of veterans who may be at risk for abdominal aortic aneurysms (AAA) based on the 2007 mandate to screen all veteran patients that meet the screening criteria. The main research objective is to automatically index three clinical conditions: pertinent negative AAA, pertinent positive AAA, and visually unacceptable image exams. We developed and evaluated a ConText-based algorithm with the GATE (General Architecture for Text Engineering) development system to automatically classify 1402 ultrasound radiology reports for AAA screening. Using the results from JAPE (Java Annotation Pattern Engine) transducer rules, we developed a feature vector to classify the radiology reports with a decision table classifier. We found that ConText performed optimally on precision and recall for pertinent negative (0.99 (0.98-0.99), 0.99 (0.99-1.00)) and pertinent positive AAA detection (0.98 (0.95-1.00), 0.97 (0.92-1.00)), and respectably for determination of non-diagnostic image studies (0.85 (0.77-0.91), 0.96 (0.91-0.99)). In addition, our algorithm can determine the AAA size measurements for further characterization of abnormality. We developed and evaluated a regular expression based algorithm using GATE for determining the three contextual conditions: pertinent negative, pertinent positive, and non-diagnostic from radiology reports obtained for evaluating the presence or absence of abdominal aortic aneurysm. ConText performed very well at identifying the contextual features. Our study also discovered contextual trigger terms to detect sub-standard ultrasound image quality. Limitations of performance included unknown dictionary terms, complex sentences, and vague findings that were difficult to classify and properly code.

    View details for DOI 10.1007/s10278-016-9889-6

    View details for PubMedID 27400914

    View details for PubMedCentralID PMC5114229

  • MR anatomy and pathology of the ulnar nerve involving the cubital tunnel and Guyon's canal. Clinical imaging Shen, L., Masih, S., Patel, D. B., Matcuk, G. R. 2015; 40 (2): 263-74


    Ulnar neuropathy is a common and frequent reason for referral to hand surgeons. Ulnar neuropathy mostly occurs in the cubital tunnel of the elbow or Guyon's canal of the wrist, and it is important for radiologists to understand the imaging anatomy at these common sites of impingement. We will review the imaging and anatomy of the ulnar nerve at the elbow and wrist, and we will present magnetic resonance imaging examples of different causes of ulnar neuropathy, including trauma, overuse, arthritis, masses and mass-like lesions, and systemic diseases. Treatment options will also be briefly discussed.

    View details for DOI 10.1016/j.clinimag.2015.11.008

    View details for PubMedID 26995584