Faculty Bibliography

OBJECTIVE:Recent research on inferior vena cava (IVC) filter utilization in the United States has largely focused on national aggregate Medicare datasets, showing recent declines. Whether these national Medicare trends are generalizable across regions and payer populations is unknown. We studied recent state-level variation in IVC filter utilization across both Medicare and private insurance populations. MATERIALS AND METHODS/METHODS:Using large individual beneficiary claims-level Medicare research identifiable files and a proprietary U.S. research database of the commercially insured population, we identified all billed IVC filter placement procedures performed between 2009 and 2015. We compared population-adjusted utilization rates by state and payer type. RESULTS:Between 2009 and 2015, IVC filter utilization across the United States declined by 36.3% (from 177.9 to 113.3 procedures per 100,000 beneficiaries) in the Medicare population and by 26.6% (from 32.7 to 24.0 procedures per 100,000 beneficiaries) in the privately insured population. For the Medicare population, state-level utilization rates varied 5.2-fold, from 48.4 to 251.3 procedures per 100,000 beneficiaries in Alaska and New Jersey, respectively. For the private insurance population, rates varied 5.5-fold, from 10.8 to 59.5 procedures per 100,000 beneficiaries in Oregon and Michigan, respectively. Nationally, utilization in the Medicare population was 5.0 times higher than that in the private insurance population (range by state, from 2.0 times higher in Hawaii to 11.1 times higher in Utah). Despite the national decline, utilization in Medicare and private insurance populations increased in five and seven states, respectively. State-level IVC filter utilization rates for the Medicare population correlated strongly with those for the privately insured population (r = 0.74; p < 0.001). In both the Medicare and privately insured populations, utilization rates correlated moderately with beneficiary age (r = 0.44 and r = 0.50, respectively; p < 0.001 for both). CONCLUSION/CONCLUSIONS:IVC filter utilization rates vary dramatically by state and payer population, and they likely depend in part on the age of the covered population. To better identify demographic and socioeconomic drivers of utilization, future research should prioritize nonaggregate multipayer claims-level approaches.

Technical advances in MRI have improved image quality and have led to expanding clinical indications for its use. However, long examination and interpretation times, as well as higher costs, still represent barriers to use of MRI. Abbreviated MRI protocols have emerged as an alternative to standard MRI protocols. These abbreviated MRI protocols seek to reduce longer MRI protocols by eliminating unnecessary or redundant sequences that negatively affect cost, MRI table time, patient comfort, image quality, and image interpretation time. However, the diagnostic information is generally not compromised. Abbreviated MRI protocols have already been used successfully for hepatocellular carcinoma screening, for prostate cancer detection, and for screening for nonalcoholic fatty liver disease as well as monitoring patients with this disease. It has been reported that image acquisition time and costs can be considerably reduced with abbreviated MRI prototcols, compared with standard MRI protocols, while maintaining a similar sensitivity and accuracy. Nevertheless, multiple applications still need to be explored in the abdomen and pelvis (eg, surveillance of metastases to the liver; follow-up of cystic pancreatic lesions, adrenal incidentalomas, and small renal masses; evaluation of ovarian cysts in postmenopausal women; staging of cervical and uterine corpus neoplasms; evaluation of müllerian duct anomalies). This article describes some successful applications of abbreviated MRI protocols, demonstrates how they can help in improving the MRI workflow, and explores potential future directions. ^©RSNA, 2019.

PURPOSE/OBJECTIVE:To assess the effect on reader performance of an interactive case-based online tutorial for prostate magnetic resonance imaging (MRI) interpretation using Prostate Imaging and Reporting Data System (PI-RADS). METHODS:An educational website was developed incorporating scrollable multiparametric prostate MRI examinations with annotated solutions based on PI-RADS version 2. Three second-year radiology residents evaluated a separate set of 60 prostate MRI examinations both before and after review of the online case material, identifying and scoring dominant lesions. These 60 examinations included 30 benign cases and 30 cases with a dominant lesion demonstrating Gleason score ≥3 + 4 tumor on fusion-targeted biopsy. The readers' pooled performance was compared between the 2 sessions using logistic regression and Wilcoxon signed rank tests. RESULTS:All readers completed the online material within four-hours. Review of the online material significantly improved sensitivity (from 57.8%-73.3%, P = 0.003) and negative predictive value (from 69.2%-78.2%, P = 0.049), but not specificity (from 70.0%-67.8%, P = 0.692) or positive predictive value (from 59.6%-64.7%, P = 0.389). Reader confidence (1-10 scale; 10 = maximal confidence) also improved significantly (from 5.6 ± 2.7 to 6.3 ± 2.6, P = 0.026). However, accuracy of assigned PI-RADS scores did not improve significantly (from 45.5%-53.3%, P = 0.149). CONCLUSION/CONCLUSIONS:An online interactive case-based website in prostate MRI interpretation improved novice readers' sensitivity and negative predictive value for tumor detection, as well as readers' confidence. This online material may serve as a resource complementing existing traditional methods of instruction by providing a more flexible educational experience among a larger volume of learners. However, further more targeted educational initiatives regarding the proper application of PI-RADS remain warranted.

Purpose: The tremendous popularity of the new integrated interventional radiology (IR) and diagnostic radiology residency highlights the importance of medical student outreach to promote a diverse new generation of trainees. In order to promote women in IR, and attract female applicants directly from medical school, the Women in IR committee (WIR) of the Resident Fellow and Student Section (RFS) of the Society of Interventional Radiology (SIR) started accepting female and honorary male medical student members in March 2018. We aimed to assess the interests and goals of medical students joining WIR to better address their needs and to guide future recruitment. Materials: This retrospective study analyzed the WIR registration form responses during a 4-week recruitment period. Prior to medical student recruitment, WIR had 38 active female resident and fellow members. Recruitment banners were sent to the RFS medical students and posted on the RFS website and social media accounts.
Result(s): Among 43 students who registered, 7%, 28%, 37% and 28% were first, second, third and fourth year students, respectively. 19% were males. When asked to select any committee activities in which they were interested, the majority indicated research (93%), educational activities (86%), publishing articles online (60%), organizing events (58%), and leading new projects (53%). When asked their goals in joining WIR, female students wanted to promote WIR (69%), network (63%), build mentorship (31%), seek more opportunities (26%), address barriers for women (23%), and make an impact in IR (23%); male students wanted to support WIR (100%), address barriers (50%), and advance IR with diversity and inclusion (50%).
Conclusion(s): Medical students showed robust interests in joining WIR. Both female and male students expressed interests in promoting WIR and addressing barriers for the gender gap. Female students expressed interests in increasing networking, mentorship, and opportunities in IR. Male students emphasized the importance of diversity and inclusion. Recruiting medical students into SIR committees and providing networking, mentorship, and projects may attract both more female and male medical students into the field.
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PURPOSE/OBJECTIVE:To determine whether the presence of an ultrasound hypoechoic region at the site of a MRI region of interest (ROI) results in improved prostate cancer (PCa) detection and predicts clinically significant PCa on MRI - ultrasound fusion targeted prostate biopsy (MRF-TB). MATERIALS AND METHODS/METHODS:Between July 2011 and June 2017, 1058 men who underwent MRF-TB and systematic biopsy by a single surgeon were prospectively entered into an IRB-approved database. MRI ROI were identified and scored for suspicion by a single radiologist. Each MRI ROI was prospectively evaluated for presence of a hypoechoic region at the site (ROI-HyR) by the surgeon and graded as 0,1,2 representing none, poorly demarcated, or well demarcated, respectively. Interaction of MRI suspicion score (mSS) and US grade (USG), and prediction of cancer detection rate (CDR) by USG, was evaluated by univariate and multivariate analysis. RESULTS:For 672 men, overall and Gleason Score (GS)≥7 CDR were 61.2% and 39.6%, respectively. CDR for USG 0,1,2 were 46.2%, 58.6%, 76.0% (p<0.001) for any cancer and 18.7%, 35.2%, 61.1% (p<0.001) for GS≥7, respectively. For MRF-TB only, GS≥7 CDR for USG 0,1,2 was 12.8%, 25.7%, 52.0% (p<0.001), respectively. On univariate analysis, among mSS 2-4, USG was predictive of GS≥7 CDR. Multivariable regression analysis revealed USG, PSAD, and mSS were predictive of GS≥7 PCa on MRF-TB. CONCLUSIONS:Ultrasound findings at the site of MRI ROI independently predict the likelihood of GS≥7 PCa, as men with a well demarcated ROI-HyR at the time of MRF-TB have a higher risk than men without.

Purpose: To assess changing utilization in extremity angiography from 2001 to 2016, focusing on relative shifts between modalities and provider specialties. Materials: Medicare PSPS Master Files from 2001-2016 were used to determine national utilization of traditional invasive catheter angiography, CTA, and MRA, normalized to extremities imaged per 100,000 beneficiaries. Result(s): From 2001 to 2016, extremity angiography increased from 769 to 1,352 total extremities imaged per 100,000 beneficiaries, largely attributable to massive early growth in CTA (22 in 2001 to 614 in 2009; plateau of 645 in 2016), with small changes in catheter angiography (702 to 676) and MRA (45 to 30). Extremity angiography shifted from 91% catheter, 6% MRA, 3% CTA in 2001 to 50% catheter, 48% CTA, and 2% MRA in 2016. For radiologists, overall angiography increased (488 to 733) due to a large increase in CTA (20 to 595) despite a large decrease in catheter (428 to 122), while MRA remained low (40 to 27); extremity angiography by radiologists shifted from 88% catheter, 8% MRA, and 4% CTA in 2001 to 81% CTA, 15% catheter, and 4% MRA in 2016. For cardiologists, there were increases in angiography overall (155 to 240) and catheter (153 to 205), and to a lesser extent in CTA (1 to 33); extremity angiography by cardiologists shifted from 99% catheter, <1% CTA, <1% MRA in 2001 to 85% catheter, 14% CTA, <1% MRA in 2016. For surgeons, overall angiography increased from 65 to 261 and was 99% catheter in both 2001 and 2016. Radiologists' market share of extremity angiography varied from 63% (2001) to 54% (2016). Despite a marked decrease in radiologists' share for catheter (61% to 17%), radiologists were the dominant provider throughout for CTA (89% to 92%) and MRA (89% to 90%). Conclusion(s): Utilization of extremity angiography in Medicare beneficiaries nearly tripled from 2001 to 2016, almost entirely due to the advent of CTA by radiologists. Cardiologists and surgeons acquired the large volume of catheter angiography given up by radiologists. Further work is necessary to assess if the growth of CTA represents additive (i.e., expanded patient populations being evaluated) vs. duplicative (i.e., same patients undergoing both tests) imaging.

Purpose: To evaluate trends in transcatheter hemodialysis conduit procedures in the Medicare population over a recent 15-year interval. Materials: Aggregate national claims data were extracted from CMS PSPS Master Files from 2001-2015 for hemodialysis conduit angiography and thrombectomy procedures. Utilization was stratified by billing specialty and site of service. Additionally, individual claims data from 2004-2015 CMS 5% Research Identifiable Files were used to assess state-level utilization. Utilization was normalized per 100,000 Medicare fee-for-service beneficiaries. Result(s): From 2001-2015, hemodialysis conduit angiography utilization rates increased from 385 to 1,045 per 100,000 beneficiaries [compound annual growth rate (CAGR) +7.4%)], and thrombectomy rates increased from 114 to 168 (CAGR +2.8%). The CAGR for angiography was, by specialty, +1.5% for radiologists, +18.4% for surgeons, and +24.0% for nephrologists, and by site, +29.1% for office and +0.8% for hospital settings. Radiologists' overall market share of angiography decreased from 81.5% in 37.0%. By combination of specialty and site of service, angiography utilization growth was greatest for nephrologists in the office (from 5 to 265) and surgeons in the office (0 to 128). The greatest decline was for radiologists in the hospital (299 to 205). At the state level, there was marked heterogeneity in dialysis angiography utilization in 2015 [0 (Wyoming) to 1,1,73 (Georgia)], temporal change in angiography utilization from 2004-2015 [CAGR -100.0% (Wyoming) to +19.9% (Nevada)], and radiologists' 2015 market share [4.8% (Washington DC) to 100.0% (North Dakota)]. Nonetheless, radiologists' market share decreased in 49 states, and in some states dramatically (e.g., in Nevada, from 100.0% in 2004 to 6.7% in 2015). Conclusion(s): Transcatheter dialysis conduit angiography utilization has grown substantially, and more so than thrombectomy. This growth has been accompanied by a drastic market shift from radiologists in the hospital to nephrologists and surgeons in the office. Despite wide geographic heterogeneity across the U.S., decreasing radiologist market share has been observed in nearly every state.

Purpose: To explore variation in downstream costs associated with cartilage lesions incidentally detected on radiographs. Materials andMethods: The cohort was composed of 120 patients with incidental, not previously diagnosed, cartilage lesions seen on appendicular plain radiographs. The population was divided into three subgroups based on the interpreting radiologist's description: enchondroma, lowgrade cartilage lesion, and chondrosarcoma. Downstream events (follow-up imaging, office visits, biopsy, tumor resection) associated with the lesions were identified from the electronic medical record. American College of Radiology (ACR) Appropriateness Criteria were used to classify radiologists' recommendations. NationalMedicare rates were used to estimate costs of downstream events. Average cost per lesion was stratified, and cost ratios were computed among subgroups.
Result(s): Average downstream cost per lesion was $75.56. Costs were 4.6 times greater in patients under the age of 65 than over. Costs were 13.2 and 13.7 times higher when radiologists characterized lesions as chondrosarcoma versus low-grade cartilage lesion and enchondroma, respectively. There was no statistically significant difference in costs between the subgroups when accounting for size and location of lesions. Compared to when follow-up imaging was neither recommended nor obtained, costs rose from $0 to $26.03 per patient when follow-up imaging was recommended and obtained, and $62.21 per patient when followup imaging was obtained despite not being recommended. Costs rose from $0 to $14.83 per patient when radiologists' recommendations for follow-up were adherent to the ACR guidelines for management of incidental bone lesions. Costs were 2.3 times greater when ordering physicians overmanaged compared with radiologists' recommendations. No malignancy was pathologically proven in the cohort.
Conclusion(s): Costs for incidental cartilage lesions vary. Size and location of lesions do not have a significant effect on downstream costs; however, radiologists' characterization and recommendation have an impact. Therefore, it is imperative that radiologists accurately characterize such lesions and recommendations reflect the best value for patient care

BACKGROUND:Patient-specific 3D models are being used increasingly in medicine for many applications including surgical planning, procedure rehearsal, trainee education, and patient education. To date, experiences on the use of 3D models to facilitate patient understanding of their disease and surgical plan are limited. The purpose of this study was to investigate in the context of renal and prostate cancer the impact of using 3D printed and augmented reality models for patient education. METHODS:Patients with MRI-visible prostate cancer undergoing either robotic assisted radical prostatectomy or focal ablative therapy or patients with renal masses undergoing partial nephrectomy were prospectively enrolled in this IRB approved study (n = 200). Patients underwent routine clinical imaging protocols and were randomized to receive pre-operative planning with imaging alone or imaging plus a patient-specific 3D model which was either 3D printed, visualized in AR, or viewed in 3D on a 2D computer monitor. 3D uro-oncologic models were created from the medical imaging data. A 5-point Likert scale survey was administered to patients prior to the surgical procedure to determine understanding of the cancer and treatment plan. If randomized to receive a pre-operative 3D model, the survey was completed twice, before and after viewing the 3D model. In addition, the cohort that received 3D models completed additional questions to compare usefulness of the different forms of visualization of the 3D models. Survey responses for each of the 3D model groups were compared using the Mann-Whitney and Wilcoxan rank-sum tests. RESULTS:All 200 patients completed the survey after reviewing their cases with their surgeons using imaging only. 127 patients completed the 5-point Likert scale survey regarding understanding of disease and surgical procedure twice, once with imaging and again after reviewing imaging plus a 3D model. Patients had a greater understanding using 3D printed models versus imaging for all measures including comprehension of disease, cancer size, cancer location, treatment plan, and the comfort level regarding the treatment plan (range 4.60-4.78/5 vs. 4.06-4.49/5, p < 0.05). CONCLUSIONS:All types of patient-specific 3D models were reported to be valuable for patient education. Out of the three advanced imaging methods, the 3D printed models helped patients to have the greatest understanding of their anatomy, disease, tumor characteristics, and surgical procedure.

RATIONALE AND OBJECTIVES/OBJECTIVE:This study aimed to characterize articles in popular general radiology journals that go uncited for a decade after publication. METHODS:Using the Web of Science database, we identified annual citation counts for 13,459 articles published in Radiology, American Journal of Roentgenology, and Academic Radiology between 1997 and 2006. From this article cohort, we then identified all original research articles that accrued zero citations within a decade of publication. A concurrent equal-sized cohort of most cited articles was created. Numerous characteristics of the uncited and most cited articles were identified and compared. RESULTS:Only 47 uncited articles went uncited for a decade after publication. When compared to the 47 most cited articles over that same window, the uncited articles were significantly (P < .05) less likely to have a clinical focus, include a nonradiologist author and authors from multiple institutions and multiple nations, report research funding support and statistically significant findings, and include punctuation marks in their titles. Compared to the most cited articles, uncited articles also had significantly (P < .05) fewer authors, abstract words, manuscript words, references, tables, figure parts, and pages, as well as smaller subject sample sizes. CONCLUSION/CONCLUSIONS:Of articles published in popular general radiology journals, only a very small number of original research investigations remained uncited a decade after publication. Given that citations reflect the impact of radiology research, this observation suggests that journals are appropriately selecting meaningful work. Investigators seeking to avoid futile publication might consider their research initiatives in light of these characteristics.