Faculty Bibliography

BACKGROUND:MR is an important imaging modality for evaluating musculoskeletal malignancies owing to its high soft tissue contrast and its ability to acquire multiparametric information. PET provides quantitative molecular and physiologic information and is a critical tool in the diagnosis and staging of several malignancies. PET/MR, which can take advantage of its constituent modalities, is uniquely suited for evaluating skeletal metastases. We reviewed the current evidence of PET/MR in assessing for skeletal metastases and provided recommendations for its use. METHODS:We searched for the peer reviewed literature related to the usage of PET/MR in the settings of osseous metastases. In addition, expert opinions, practices, and protocols of major research institutions performing research on PET/MR of skeletal metastases were considered. RESULTS:Peer-reviewed published literature was included. Nuclear medicine and radiology experts, including those from 13 major PET/MR centers, shared the gained expertise on PET/MR use for evaluating skeletal metastases and contributed to a consensus expert opinion statement. [18F]-FDG and non [18F]-FDG PET/MR may provide key advantages over PET/CT in the evaluation for osseous metastases in several primary malignancies. CONCLUSION/CONCLUSIONS:PET/MR should be considered for staging of malignancies where there is a high likelihood of osseous metastatic disease based on the characteristics of the primary malignancy, hight clinical suspicious and in case, where the presence of osseous metastases will have an impact on patient management. Appropriate choice of tumor-specific radiopharmaceuticals, as well as stringent adherence to PET and MR protocols, should be employed.

PURPOSE/OBJECTIVE:TikTok, the fastest growing social media application worldwide, has been infrequently studied in medicine. We analyzed the top radiology-related posts on TikTok in order to describe opportunities for radiology engagement. MATERIALS AND METHODS/METHODS:We retrieved the top 300 posts meeting the search criteria "radiology." User- and post-related data were categorized based on a prespecified coding system. Descriptive statistics were reported. Kruskal-Wallis H and Mann-Whitney U tests were performed to assess for differences in followers, plays, likes, and comments among posts and users. RESULTS:284 working posts were broadcast by 187 unique users with median 119 followers (interquartile range [IQR]: 31-1,206) and 20 posts (IQR: 7-49). Most (81%, 151/187) were nonphysician radiology personnel, while only 5% (9/187) were radiologists. Posts by radiologists had more plays than those by nonphysician radiology personnel (median 3643 vs 1282, P = 0.001). The 284 posts had median 1520 plays (IQR 429-4374), 60 likes (IQR 18-272), and 2 comments (IQR 0-9). Most posts were work-related (184/284, 65%), followed by clinical (68/284, 24%), personal (30/284, 11%), or promotional (2/284, 1%). However, posts by radiologists were mostly clinical (65%, 31/48) and represented a large majority of posted imaging cases (29/33, 88%). Posts about COVID-19 represented 38% (107/284) of the study sample and 48% (93/193) of posts after the first U.S. COVID-19 case COVID-19 posts had significantly more comments (3 vs. 2, P = 0.034) and more likes approaching significance (89 vs 51, P = 0.134) than non-COVID-19 posts. CONCLUSIONS:Though radiologists represent a minority of TikTok users their post represent the majority of this platform's clinical content. This presents an important opportunity for radiologists to utilize TikTok for contemporary, unique content creation and engagement with nonphysician radiology personnel.

OBJECTIVES/OBJECTIVE:To perform a systematic review on apparent diffusion coefficient (ADC) values of renal tumor subtypes and meta-analysis on the diagnostic performance of ADC for differentiation of localized clear cell renal cell carcinoma (ccRCC) from other renal tumor types. METHODS:Medline, Embase, and the Cochrane Library databases were searched for studies published until May 1, 2019, that reported ADC values of renal tumors. Methodological quality was evaluated. For the meta-analysis on diagnostic test accuracy of ADC for differentiation of ccRCC from other renal lesions, we applied a bivariate random-effects model and compared two subgroups of ADC measurement with vs. without cystic and necrotic areas. RESULTS:We included 48 studies (2588 lesions) in the systematic review and 13 studies (1126 lesions) in the meta-analysis. There was no significant difference in ADC of renal parenchyma using b values of 0-800 vs. 0-1000 (p = 0.08). ADC measured on selected portions (sADC) excluding cystic and necrotic areas differed significantly from whole-lesion ADC (wADC) (p = 0.002). Compared to ccRCC, minimal-fat angiomyolipoma, papillary RCC, and chromophobe RCC showed significantly lower sADC while oncocytoma exhibited higher sADC. Summary estimates of sensitivity and specificity to differentiate ccRCC from other tumors were 80% (95% CI, 0.76-0.88) and 78% (95% CI, 0.64-0.89), respectively, for sADC and 77% (95% CI, 0.59-0.90) and 77% (95% CI, 0.69-0.86) for wADC. sADC offered a higher area under the receiver operating characteristic curve than wADC (0.852 vs. 0.785, p = 0.02). CONCLUSIONS:ADC values of kidney tumors that exclude cystic or necrotic areas more accurately differentiate ccRCC from other renal tumor types than whole-lesion ADC values. KEY POINTS/CONCLUSIONS:• Selective ADC of renal tumors, excluding cystic and necrotic areas, provides better discriminatory ability than whole-lesion ADC to differentiate clear cell RCC from other renal lesions, with area under the receiver operating characteristic curve (AUC) of 0.852 vs. 0.785, respectively (p = 0.02). • Selective ADC of renal masses provides moderate sensitivity and specificity of 80% and 78%, respectively, for differentiation of clear cell renal cell carcinoma (RCC) from papillary RCC, chromophobe RCC, oncocytoma, and minimal-fat angiomyolipoma. • Selective ADC excluding cystic and necrotic areas are preferable to whole-lesion ADC as an additional tool to multiphasic MRI to differentiate clear cell RCC from other renal lesions whether the highest b value is 800 or 1000.

Diverticular disease of the colon and small bowel is an important cause of pathology leading to emergency department visits and urgent gastrointestinal surgery. CT is a highly sensitive and specific modality for the diagnosis of acute diverticulitis and its complications as well as for the exclusion of alternate causes of pathology. Ultrasound, MRI and virtual CT colonoscopy have important adjunct roles for screening and workup of complications in specific patient populations. While diverticular disease most commonly involves the descending and sigmoid colon, it can also affect the proximal colon and small bowel. Acute diverticulitis may be categorized as uncomplicated or complicated according to the degree of inflammatory changes and related complications it induces, although some degree of overlap exists in clinical practice. Uncomplicated diverticulitis is classically characterized by localized inflammation surrounding a diverticulum ranging from wall thickening and phlegmonous change to the development of small, localized pericolic abscesses. Complicated forms of disease manifest with larger pericolic and distant abscesses, fistulae to adjacent organs, perforation, and peritonitis. Recurrent episodes of diverticulitis may lead to muscular hypertrophy of the bowel wall and luminal narrowing, potentially leading to bowel obstruction. Several imaging features may help to differentiate diverticulitis from colonic malignancy, however this remains a diagnostic imaging challenge that often requires further evaluation with colonoscopy. In this review, we discuss the pathophysiology and key imaging features of acute diverticulitis and its complications. We explore both common and uncommon presentations of the disease involving the colon and small bowel, acute and chronic manifestations of disease, and pitfalls to recognize when imaging alone may be insufficient to distinguish benign from malignant.

PURPOSE/OBJECTIVE:Acclimating residents to radiology residency requires attention to new responsibilities, educational material, and social cohesion. To this end, we instituted a structured orientation week for incoming residents and assessed its impact. PROCEDURES/METHODS:During the first weeks of July 2016 and 2017, first year residents attended a five day orientation free of clinical duties, consisting of didactics, hands-on training sessions, and social events. After two orientation cohorts, residents who completed orientation week, and two cohorts who had not, were given a voluntary, anonymous survey using Likert scale questions (1 [worst] to 5 [best]) regarding preparedness for responsibilities, learning, and social cohesion. Residents were asked which components were or would have been helpful. Independent samples t-tests were performed to evaluate differences between the two groups (two-tailed p < 0.05). FINDINGS/RESULTS:21/37 (57%) residents participated. Higher percentages of residents who participated in the orientation week gave scores ≥4 when asked about preparedness for rotations (70% vs. 36%), learning new material (80% vs. 36%), and class cohesiveness (90% vs. 70%). Mean scores on these questions were also higher for these residents with regards to: preparedness for new responsibilities (3.7 vs. 2.9), learning new material (3.8 vs. 2.9), and class cohesiveness (4.5 vs. 3.8), with differences approaching significance (p = 0.09-0.15). Individual components receiving most votes of ≥4 were social outings, resident lunches, didactic lectures, and PACS training. CONCLUSION/CONCLUSIONS:A weeklong orientation program free of clinical duties was valued by residents and contributed to acclimation to new responsibilities, education, and social cohesion.

Prostate cancer screening reduces advanced disease and prostate cancer death but is controversial due to downstream harms including unnecessary biopsies and overtreatment. In 2012 the United States Preventive Services Task Force (USPSTF) recommended against screening men for prostate cancer, a practice common since the early 1990's. This dramatic policy change was opposed by many physicians and patient groups. Our group reported on the Twitter response within 24 hours of these guidelines, showing a missed opportunity for greater advocacy since the majority of tweets did not express an opinion.

Facial transplant (FT) is a viable option for patients with severe craniomaxillofacial deformities. Transplant imaging requires coordination between radiologists and surgeons and an understanding of the merits and limitations of imaging modalities. Digital subtraction angiography and CT angiography are critical to mapping vascular anatomy, while volume-rendered CT allows evaluation of osseous defects and landmarks used for surgical cutting guides. This article highlights the components of successful FT imaging at two institutions and in two index cases. A deliberate stepwise approach to performance and interpretation of preoperative FT imaging, which consists of the modalities and protocols described here, is essential to seamless integration of the multidisciplinary FT team. ^©RSNA, 2019 See discussion on this article by Lincoln .

BACKGROUND:The value of dynamic contrast-enhanced (DCE) sequences in prostate MRI compared with noncontrast MRI is controversial. PURPOSE/OBJECTIVE:To evaluate the population net benefit of risk stratification using DCE-MRI for detection of high-grade prostate cancer (HGPCA), with or without high spatiotemporal resolution DCE imaging. STUDY TYPE/METHODS:Decision curve analysis. POPULATION/METHODS:Previously published patient studies on MRI for HGPCA detection, one using DCE with golden-angle radial sparse parallel (GRASP) images and the other using standard DCE-MRI. FIELD STRENGTH/SEQUENCE/UNASSIGNED:GRASP or standard DCE-MRI at 3 T. ASSESSMENT/RESULTS:Each study reported the proportion of lesions with HGPCA in each Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) category (1-5), before and after reclassification of peripheral zone lesions from PI-RADS 3-4 based on contrast-enhanced images. This additional risk stratifying information was translated to population net benefit, when biopsy was hypothetically performed for: all lesions, no lesions, PI-RADS ≥3 (using NC-MRI), and PI-RADS ≥4 on DCE. STATISTICAL TESTS/UNASSIGNED:Decision curve analysis was performed for both GRASP and standard DCE-MRI data, translating the avoidance of unnecessary biopsies and detection of HGPCA to population net benefit. We standardized net benefit values for HGPCA prevalence and graphically summarized the comparative net benefit of biopsy strategies. RESULTS:For a clinically relevant range of risk thresholds for HGPCA (>11%), GRASP DCE-MRI with biopsy of PI-RADS ≥4 lesions provided the highest net benefit, while biopsy of PI-RADS ≥3 lesions provided highest net benefit at low personal risk thresholds (2-11%). In the same range of risk thresholds using standard DCE-MRI, the optimal strategy was biopsy for all lesions (0-15% risk threshold) or PI-RADS ≥3 on NC-MRI (16-33% risk threshold). DATA CONCLUSION/UNASSIGNED:GRASP DCE-MRI may potentially enable biopsy of PI-RADS ≥4 lesions, providing relatively preserved detection of HGPCA and avoidance of unnecessary biopsies compared with biopsy of all PI-RADS ≥3 lesions. J. Magn. Reson. Imaging 2019.

PURPOSE/OBJECTIVE:The purpose of this study was to reduce radiation exposure during pediatric central venous line (CVL) placement by implementing a radiation safety process including a radiation safety briefing and a job-instruction model with a preradiation time-out. METHODS:We reviewed records of all patients under 21 who underwent CVL placement in the operating room covering 22 months before the intervention through 10 months after 2013-2016. The intervention consisted of a radiation safety briefing by the surgeon to the intraoperative staff before each case and a radiation safety time-out. We measured and analyzed the dose area product (DAP), total radiation time pre- and postintervention, and the use of postprocedural chest radiograph. RESULTS:, P < 0.001) and a 73% decrease in the median radiation time (28 vs 7.6 s, P < 0.001). Additionally, there was a significant reduction in use of confirmatory CXR (95% vs 15%, P < 0.01). CONCLUSION/CONCLUSIONS:A preoperative radiation safety briefing and a radiation safety time-out supported by a job-instruction model were effective in significantly lowering the absorbed doses of radiation in children undergoing CVL insertion. TYPE OF STUDY/METHODS:Case-control study. LEVEL OF EVIDENCE/METHODS:Level III.

Purpose: To determine the impact of DWI and T2WI acquisition parameters on first-order hepatic texture measures at 3T MRI.
Material(s) and Method(s): Five healthy volunteers (3 M/2F, mean 40 years old) were prospectively imaged at 3T using baseline liver free-breathing DWI and T2WI acquisition twice to assess scan-rescan repeatability. Three modifications to acquisition parameters were also performed individually: decreased averages (2 vs. 4); lower resolution (DWI: 128x96 vs. 192x144 and T2WI: 192x192 vs. 320x320); and increased slice thickness (8 vs. 4 mm). A single reader placed four co-registered hepatic ROIs using 3D Slicer v4.8.1 (https://urldefense.proofpoint.com/v2/url?u=http-3A__www.slicer.org&d=DwIFAg&c=j5oPpO0eBH1iio48DtsedeElZfc04rx3ExJHeIIZuCs&r=EQR3KLkQ5UWCWWT7EfebH2P_dJeKQhvwk7yvrJe5GJY&m=VVljDEDjGLS_4z5jZ0uX9AVqXkAPM24hpGmZl06It_E&s=TQM-Y7ippXB-a-cXGwkMg-DnVAXTLHOB9hyiAIzdwXQ&e= ). 10 first-order histogram texture features (average of the four ROI) were compared to baseline acquisition. Percent difference (%diff) and coefficient of variance (CV) were computed using MedCalc.
Result(s): For ADC, 8 out of 10 parameters were repeat-able with <10% scan-rescan %diff; Skewness and Minimum were least repeatable with >10% scan-rescan %diff. Entropy was the only parameter that had < 10% CV and %diff for all acquisition schemes; all other parameters had >10% CV for at least one modified acquisition scheme. Skewness, Minimum, and Variance had the largest average CV. Change in slice thickness had the largest impact on most texture features. For T2WI, 9 out of 10 parameters were repeatable with <10% scan-rescan %diff; Skewness had >10% scan-rescan %diff. Entropy and Uniformity were the only two parameters that had <15% CV and %diff for all acquisition schemes. Change in slice thickness had the largest impact on most texture features.
Conclusion(s): ADC and T2WI first-order hepatic texture features, except for entropy, depend on acquisition parameters. Care must be taken to maintain identical acquisition schemes to compare changes in these features, such as after treatment