Faculty Bibliography

RATIONALE AND OBJECTIVES:To validate the educational value of a newly created learning application in enhancing prostate MRI training of radiologists for detecting prostate cancer using an observer study. MATERIALS AND METHODS:An interactive learning app, LearnRadiology, was developed using a web-based framework to display multi-parametric prostate MRI images with whole-mount histology for 20 cases curated for unique pathology and teaching points. Twenty new prostate MRI cases, different from the ones used in the web app, were uploaded on 3D Slicer. Three radiologists (R1: radiologist; R2, R3: residents) blinded to pathology results were asked to mark areas suspected of cancer and provide a confidence score (1-5, with 5 being high confidence level). Then after a minimum memory washout period of 1 month, the same radiologists used the learning app and then repeated the same observer study. The diagnostic performance for detecting cancers before and after accessing the learning app was measured by correlating MRI with whole-mount pathology by an independent reviewer. RESULTS:The 20 subjects included in the observer study had 39 cancer lesions (13 Gleason 3 + 3, 17 Gleason 3 + 4, 7 Gleason 4 + 3, and 2 Gleason 4 + 5 lesions). The sensitivity (R1: 54% → 64%, P = 0.08; R2: 44% → 59%, P = 0.03; R3: 62% → 72%, P = 0.04) and positive predictive value (R1: 68% → 76%, P = 0.23; R2: 52% → 79%, P = 0.01; R3: 48% → 65%, P = 0.04) for all 3 radiologists improved after using the teaching app. The confidence score for true positive cancer lesion also improved significantly (R1: 4.0 ± 1.0 → 4.3 ± 0.8; R2: 3.1 ± 0.8 → 4.0 ± 1.1; R3: 2.8 ± 1.2 → 4.1 ± 1.1; P < 0.05). CONCLUSION:The web-based and interactive LearnRadiology app learning resource can support medical student and postgraduate education by improving diagnostic performance of trainees for detecting prostate cancer.

Gunshot wounds (GSWs) are an important cause of disability and death in the USA. Although radiography is limited in its ability to detect bullet types, a projectile introduced during the last decade, the R.I.P. bullet by G2 Research, consists of a base slug connected to 6 to 8 sharp trocars designed to diverge within soft tissue following impact, resulting in what we believe to be a unique imaging appearance that can be confusing to those not familiar with this particular projectile. Furthermore, this bullet is 100% copper, which may allow for safe imaging with magnetic resonance imaging if correctly identified prior to scanning.

Gender-affirming surgery is a group of surgical procedures that alters the physical appearance of a transgender person to resemble that socially associated with their identified gender. Masculinization and feminization surgeries include chest and breast surgery as well as genital reconstruction. The genital reconstruction surgeries have unique anatomic imaging features and are associated with complications that may require radiologic evaluation. This review provides a review of the imaging anatomy, expected findings, and complications associated with gender-affirming surgeries.

Multiparametric MRI (mpMRI) of the prostate has evolved to be an integral component for the diagnosis, risk stratification, staging, and targeting of prostate cancer. However, anatomic and histologic mimics of prostate cancer on mpMRI exist. Anatomic feature that mimic prostate cancer on mpMRI include anterior fibromuscular stroma, normal central zone, periprostatic venous plexus, and thickened surgical capsule (transition zone pseudocapsule). Benign conditions such as post-biopsy hemorrhage, prostatitis or inflammation, focal prostate atrophy, benign prostatic hyperplasia nodules, and prostatic calcifications can also mimic prostate cancer on mpMRI. Technical challenges and other pitfalls such as image distortion, motion artifacts, and endorectal coil placements can also limit the efficacy of mpMRI. Knowledge of prostate anatomy, location of the lesion and its imaging features on different sequences, and being familiar with the common pitfalls are critical for the radiologists who interpret mpMRI. Therefore, this article reviews the pitfalls (anatomic structures and technical challenges) and benign lesions or abnormalities that may mimic prostate cancer on mpMRI and how to interpret them.

Imaging studies of the hands and fingers are common, and radiologists are generally comfortable with traumatic and degenerative conditions which arise frequently in daily practice. However, a variety of common and uncommon soft-tissue tumors also occur in the hand, the appropriate diagnosis of which can be a source of confusion for both clinicians and radiologists. These lesions often have overlapping imaging characteristics; however, a structured approach can help provide a focused differential diagnosis and impact further workup and management. We discuss several such tumors, categorizing them as cystic-appearing, noncystic masses along tendons and aponeuroses, adipocytic tumors, vascular lesions, and miscellaneous lesions with imaging features that can aid diagnosis.

OBJECTIVE:To evaluate whether specific clinical or radiographic factors predict inferior vena cava (IVC) or abdominal aortic (AA) resection or reconstruction (RoR) at the time of postchemotherapy retroperitoneal lymph node dissection (RPLND) for germ cell tumors of the testicle. MATERIALS AND METHODS:Two hundred seventy-seven patients undergoing postchemotherapy RPLND at two institutions between 2005 and 2015 were identified. Preoperative imaging was reviewed with radiologists blinded to operative details. Univariable and multivariable logistic regressions were performed, and a model was created to predict the need for great vessel RoR using radiographic and clinical factors. RESULTS:Of 97 patients with preoperative imaging and clinical data available, 16 (17%) underwent RoR at RPLND. On univariable analysis dominant mass size, degree of circumferential vessel involvement, and vessel deformity were associated with RoR (all P <.05). No patients with clinical stage IIA or IIB disease at diagnosis required RoR. In the multivariable model, mass involvement of the IVC >135° (odds ratio 65.5, 7.8-548, P <.01) and involvement of the AA >330° (odds ratio 29.0, 3.44-245, P <.01) were predictive for RoR. These thresholds yielded a PPV of 48% and 50% and a NPV of 92% and 97% for IVC and AA RoR, respectively. CONCLUSION:Degree of circumferential involvement of the great vessels is an independent predictor for resection or reconstruction of the IVC or AA at postchemotherapy RPLND. Patients at high risk of great vessel reconstruction should be informed accordingly and have the proper teams available for complex vascular reconstruction.

OBJECTIVE:The purpose of this study is to describe the quantitative and qualitative findings of multiparametric prostate MRI performed after MRI-guided focal laser ablation of prostate cancer. MATERIALS AND METHODS:A total of 27 consenting patients met the study inclusion criteria, which included but were not limited to the presence of clinical category T1c-T2a prostate cancer with a Gleason score of 7 or less, having undergone prostate biopsy before and after focal laser ablation, and having undergone MRI before ablation, immediately after ablation, and 3 and 12 months after ablation. Signal changes were evaluated both qualitatively and quantitatively and were then correlated with the results of subsequent biopsy performed at 3 and 12 months after ablation. RESULTS:MRI performed immediately after ablation revealed a hypovascular defect in the ablation zone, with patchy or bandlike decreased T2 signal most commonly noted at 3 months (in 66.7% of ablated lesions) and T2 scarring observed in most lesions (66.7%) at 12 months. Patchy or bandlike decreased apparent diffusion coefficient signal and scarlike changes were most prevalent at 3 months after ablation (50.0% of lesions), and these features remained the most commonly observed findings at 12 months after ablation (27.8% of lesions). At 12 months after ablation, 10 patients were found to have recurrent tumor, with three patients found to have persistent cancer when biopsy was performed at the ablation site. All postablation biopsy cases with positive results showed suspicious T2 and apparent diffusion coefficient characteristics, which were considered to be a well-defined nodular intermediate signal on both of these sequences. Two of the patients for whom positive biopsy findings were noted had focal enhancement of the ablation zone. A significant reduction in the forward volume transfer constant after ablation was found at the ablation site on follow-up examination. CONCLUSION:Multiparametric MRI can reveal postablation changes in the prostate and can be a valuable tool for monitoring patients who have undergone MRI-guided focal laser ablation.

Multiparametric MR imaging is widely embraced for the diagnosis, staging, and surveillance of prostate cancer. However, normal anatomic structures and many benign entities have overlapping imaging features with prostate cancer. Although some of these entities require biopsy and histopathologic diagnosis, some have characteristic imaging features that are suggestive of their diagnosis. Knowledge of these pitfalls is important in establishing a correct diagnosis and avoiding unnecessary biopsies, as these entities are encountered routinely in clinical practice.