Faculty Bibliography

OBJECTIVES/OBJECTIVE:To assess the inter-reader variability in response assessment for HCC treated with radioembolization (TARE) compared with 3D quantitative criteria (qEASL); and to evaluate their role in prediction of pathological necrosis and clinical outcomes. MATERIALS AND METHODS/METHODS:57 patients with 77 HCCs who underwent TARE were included. Five radiologists recorded multiple imaging features and assigned mRECIST/LIRADS Treatment Response (TR) categories on post-treatment MRI at 4-6 weeks and 6-9 months after TARE. qEASL categories were assigned by a separate reader. Inter-reader variability between LIRADS TR/mRECIST/qEASL were evaluated and hazards regression was used in predicting clinical outcomes. RESULTS:Inter-reader agreement was fair for mRECIST (K = 0.43 and 0.34 at first and second follow-up respectively); moderate for LIRADS TR (K = 0.48 and 0.53 at first and second follow-up respectively). Inter-criterion agreement was moderate to substantial (r = 0.41-0.65 and r = 0.54-0.60 at first and second follow-up) for mRECIST-qEASL. LIRADS TR correlated well with qEASL for all readers at both follow-ups (K = 0.45-0.78; K = 0.39-0.77 for first and second follow-up). qEASL was the most accurate in predicting Tumor-Free Survival (TFS) on first (HR 2.23 [1.44-3.46], p < 0.001) and second (HR 1.69 [1.15-2.48], p = 0.008) follow-up. LIRADS TR was the most accurate in predicting histopathological necrosis (8 patients underwent liver transplantation and 1 patient underwent tumor resection during the period of the study). CONCLUSIONS:HCC response assessment following TARE is challenging, resulting in poor to moderate inter-reader agreement for mRECIST, and moderate inter-reader agreement for LIRADS TR response assessment criteria. qEASL outperformed mRECIST criteria for early identification of responders and predicting TFS, suggesting an advantage in volumetric tumor response assessment. LIRADS TR outperformed other criteria in predicting pathological necrosis.

The role of the radiologist in the diagnosis and management of patients with endometriosis is increasing. Improvement in MRI imaging techniques has improved detection rate of subtle manifestations of endometriosis by radiologists. Therefore, the role of imaging in the diagnosis and follow-up after treatment is also likely to increase. Knowledge of new medical management pathways used in treating patients with endometriosis-related pain is important. The knowledge of various medication regimens will allow radiologists to continue to evaluate baseline disease, and to potentially assess for imaging response/stability to these medications. This article will review the current medical therapies in use in the management of endometriosis-related pain and describe potential imaging-related findings expected with these therapies.

Endometriosis is a common entity causing chronic pain and infertility in women. The gold standard method for diagnosis is diagnostic laparoscopy, which is invasive and costly. MRI has shown promise in its ability to diagnose endometriosis and its efficacy for preoperative planning. The Society of Abdominal Radiology established a Disease-Focused Panel (DFP) to improve patient care for patients with endometriosis. In this article, the DFP performs a literature review and uses its own experience to provide technical recommendations on optimizing MRI Pelvis for the evaluation of endometriosis.

OBJECTIVE. The objective of this article is to assess radiologist concordance in characterizing thyroid nodules using the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS), focusing on the effect of radiologist experience on reader concordance. MATERIALS AND METHODS. Three experienced and three less experienced radiologists assessed 150 thyroid nodules using the TI-RADS lexicon. Percent concordance was determined for various endpoints. RESULTS. Interreader concordance for the five TI-RADS categories was 87.2% for shape, 81.2% for composition, 76.1% for echogenicity, 72.9% for margins, and 69.8% for echogenic foci. Concordance for individual features was 96.3% for rim calcifications, 90.8% for macrocalcifications, 90.1% for spongiform, 83.5% for comet tail artifact, and 77.7% for punctate echogenic foci. Concordance for the TI-RADS level and recommendation for fine-needle aspiration (FNA) were 50.4% and 78.9%, respectively. Concordance was significantly (p < 0.05) higher for less experienced readers in identifying margins (84.3% vs 67.4%), echogenic foci (76.9% vs 69.3%), comet tail artifact (89.6% vs 79.2%), and punctate echogenic foci (85.3% vs 75.5%), and lower for peripheral rim calcifications (95.0% vs 97.8 %), but was not different (p > 0.05) for the remaining categories and features. CONCLUSION. A range of TI-RADS categories, features, and recommendations for FNA had generally moderate interreader agreement among six radiologists. Our results show that concordance for numerous characteristics was significantly higher for the less experienced versus the more experienced readers. These results suggest that less experienced readers relied more on the explicit TI-RADS criteria, whereas the experienced radiologists partially relied on their accumulated experience when forming impressions. However, the overall TI-RADS level and recommendation for FNA were unaffected, supporting the robustness of the TI-RADS lexicon and its continued use in practice.

Endometriosis is a common gynecologic disorder characterized by the presence of ectopic endometrial tissue outside the endometrial cavity. Magnetic Resonance Imaging (MRI) has become a mainstay for diagnosis and staging of this disease. In the literature, significant heterogeneity exists in the descriptions of imaging findings and anatomic sites of involvement. The Society of Abdominal Radiology's Endometriosis Disease-Focused Panel presents this consensus document to establish an MRI lexicon for endometriosis MRI evaluation and anatomic localization.

PURPOSE/OBJECTIVE:To propose a highly accelerated, high-resolution dynamic contrast-enhanced MRI (DCE-MRI) technique called GRASP-Pro (golden-angle radial sparse parallel imaging with imProved performance) through a joint sparsity and self-calibrating subspace constraint with automated selection of contrast phases. METHODS:GRASP-Pro reconstruction enforces a combination of an explicit low-rank subspace-constraint and a temporal sparsity constraint. The temporal basis used to construct the subspace is learned from an intermediate reconstruction step using the low-resolution portion of radial k-space, which eliminates the need for generating the basis using auxiliary data or a physical signal model. A convolutional neural network was trained to generate the contrast enhancement curve in the artery, from which clinically relevant contrast phases are automatically selected for evaluation. The performance of GRASP-Pro was demonstrated for high spatiotemporal resolution DCE-MRI of the prostate and was compared against standard GRASP in terms of overall image quality, image sharpness, and residual streaks and/or noise level. RESULTS:Compared to GRASP, GRASP-Pro reconstructed dynamic images with enhanced sharpness, less residual streaks and/or noise, and finer delineation of the prostate without prolonging reconstruction time. The image quality improvement reached statistical significance (P < 0.05) in all the assessment categories. The neural network successfully generated contrast enhancement curves in the artery, and corresponding peak enhancement indexes correlated well with that from the manual selection. CONCLUSION/CONCLUSIONS:GRASP-Pro is a promising method for rapid and continuous DCE-MRI. It enables superior reconstruction performance over standard GRASP and allows reliable generation of artery enhancement curve to guide the selection of desired contrast phases for improving the efficiency of GRASP MRI workflow.

BACKGROUND:Evaluation of prostate MRI relies on diffusion-weighted imaging (DWI), commonly distorted by susceptibility artifacts, thereby creating a need for approaches to correct such distortion. PURPOSE/OBJECTIVE:To compare geometric distortion on prostate MRI between standard DWI and a geometric distortion correction method for DWI described as static distortion correction DWI (SDC DWI). STUDY TYPE/METHODS:Retrospective case study. POPULATION/METHODS:Thirty patients (ages 31-81 years) undergoing prostate MRI. SEQUENCE/UNASSIGNED:-field map to estimate geometric distortions. ASSESSMENT/RESULTS:WI) as an anatomic standard. Pixel shifts and apparent diffusion coefficient (ADC) values were compared between prostate contours applied to the SDC DWI and standard DWI sequences. Detailed characterization of the impact of SDC DWI was performed in three representative patients. STATISTICAL TESTS/UNASSIGNED:One-way analysis of variance (ANOVA) test, Spearman correlation test, and Bland-Altman plots were calculated. RESULTS:= 0.21). DATA CONCLUSION/UNASSIGNED:SDC DWI appears to correct for susceptibility-related pixel shifts in the prostate compared with standard DWI, which may have value for assessing prostate lesions obscured by geometric warping. Level of Evidence 4 Technical Efficacy Stage 1 J. Magn. Reson. Imaging 2019.

BACKGROUND:and diffusion-weighted imaging (DWI) can be utilized as a screening exam. PURPOSE/OBJECTIVE:To review the accuracy and feasibility of an interdisciplinary prospective contrast-enhanced MRI pelvis with DWI screening system for LMS prior to fibroid resection. STUDY TYPE/METHODS:Retrospective cohort study. POPULATION/METHODS:In all, 1960 adult female patients aged 18-87 undergoing screening MRI pelvis prior to uterine fibroid resection. FIELD STRENGTH/SEQUENCE/UNASSIGNED:-weighted imaging, DWI, and contrast-enhanced images were acquired at 1.5 T and 3.0 T. ASSESSMENT/RESULTS:signal intensity, irregular margins, hemorrhage, and necrosis. A preliminary cost-effectiveness analysis was performed, comparing the costs of treatment of uterine fibroids with vs. without a collaborative screening protocol using MRI. STATISTICAL TESTS/UNASSIGNED:Sensitivity, specificity, positive predictive value, and negative predictive value were obtained from the prospective evaluations. Student's t-tests were used to compare demographics and apparent diffusion coefficient values between LMS and false-positive results. RESULTS:We prospectively identified LMS patients with 100% sensitivity and 97% specificity. Preliminary cost analysis demonstrated that the MR screening protocol increased life expectancy by 0.04 years at a cost of $12,937 per life-year gained. DATA CONCLUSION/UNASSIGNED:MRI is an effective and potentially economic screening test, especially with standardized reporting and coordination with clinicians. LEVEL OF EVIDENCE/METHODS:3 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019.

Funding for research has become increasingly difficult to obtain in an environment of decreasing clinical revenue, increasing research costs, and growing competition for federal and nonfederal funding sources. This paper identifies critical requirements to build and sustain a successful radiology research program (eg, key personnel and leadership, research training and mentorship, infrastructure, institutional and departmental funding or support), reviews the current state of available funding for radiology (including federal, nonfederal, philanthropy, crowdfunding, and industry), and describes promising opportunities for future funding (eg, health services, comparative effectiveness, and patient-centered outcomes research). The funding climate, especially at the federal level, changes periodically, so it is important to have radiology-specific organizations such as the American College of Radiology and the Academy of Radiology Research serving as our key advocates. Key to obtaining any funding, no matter what the source, is a well-formulated grant proposal, so a review of opportunities specifically available to radiologists to develop and hone their grant-writing skills is provided. Effective and sustained funding for radiology research has the potential to cultivate young researchers, bolster quality research, and enhance health care. Those interested in pursuing research need to be aware of the ever-changing funding landscape, research priority areas, and the resources available to them to succeed. To succeed, radiology researchers need to think about diversification and flexibility in their interests, developing multidisciplinary and multi-institutional projects, and engaging a broader base of stakeholders that includes patients.