Faculty Bibliography

BACKGROUND:The number of prostate biopsy cores that need to be taken from each magnetic resonance imaging (MRI) region of interest (ROI) to optimize sampling while minimizing overdetection has not yet been clearly elucidated. OBJECTIVE:To characterize the incremental value of additional MRI-ultrasound (US) fusion targeted biopsy cores in defining the optimal number when planning biopsy and to predict men who might benefit from more than two targeted cores. DESIGN, SETTING, AND PARTICIPANTS/METHODS:This was a retrospective cohort study of MRI-US fusion targeted biopsies between 2015 and 2017. INTERVENTION/METHODS:MRI-US fusion targeted biopsy in which four biopsy cores were directed to each MRI-targeted ROI. OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSIS/UNASSIGNED:The MRI-targeted cores representing the first highest Gleason core (FHGC) and first clinically significant cancer core (FCSC; GS≥3+4) were evaluated. We analyzed the frequency of FHGC and FCSC among cores 1-4 and created a logistic regression model to predict FHGC >2. The number of unnecessary cores avoided and the number of malignancies missed for each Gleason grade were calculated via clinical utility analysis. The level of agreement between biopsy and prostatectomy Gleason scores was evaluated using Cohen's κ. RESULTS AND LIMITATIONS/CONCLUSIONS:A total of 479 patients underwent fusion targeted biopsy with four individual cores, with 615 ROIs biopsied. Among those, FHGC was core 1 in 477 (76.8%), core 2 in 69 (11.6%), core 3 in 48 (7.6%), and core 4 in 24 men (4.0%) with any cancer. Among men with clinically significant cancer, FCSC was core 1 in 191 (77.8%), core 2 in 26 (11.1%), core 3 in 17 (6.2%), and core 4 in 11 samples (4.9%). In comparison to men with a Prostate Imaging-Reporting and Data System (PI-RADS) score of 5, patients were significantly less likely to have FHGS >2 if they had PI-RADS 4 (odds ratio [OR] 0.287; p=0.006), PI-RADS 3 (OR 0.284; p=0.006), or PI-RADS 2 (OR 0.343; p=0.015). Study limitations include a single-institution experience and the retrospective nature. CONCLUSIONS:Cores 1-2 represented FHGC 88.4% and FCSC 88.9% of the time. A PI-RADS score of 5 independently predicted FHGC >2. Although the majority of cancers in our study were appropriately characterized in the first two biopsy cores, there remains a proportion of men who would benefit from additional cores. PATIENT SUMMARY/UNASSIGNED:In men who undergo magnetic resonance imaging-ultrasound fusion targeted biopsy, the first two biopsy cores diagnose the majority of clinically significant cancers. However, there remains a proportion of men who would benefit from additional cores.

PURPOSE/OBJECTIVE:The aim of this study was to assess changing Medicare volumes of, and coverage for, secondary interpretations of diagnostic imaging examinations stratified by modality and body region service families. METHODS:Medicare Physician/Supplier Procedure Summary Master Files for 2003 to 2016 were obtained. Aggregate Part B fee-for-service claims frequency and payment data were isolated for noninvasive diagnostic imaging and stratified by service family. Using published Medicare payment rules, secondary interpretations were identified as studies billed using both modifiers 26 and 77. Billed and denied services volumes were calculated and compared across modality and body region service families. RESULTS:Seven service families showed a compound annual growth rate from 2003 to 2016 of >20% (an additional 12 service families, >10% growth). For select high-volume service families (chest radiography and fluoroscopy [R&F], brain MRI, and abdominal and pelvic CT), relative growth in billed secondary interpretation services exceeded that for primary interpretations. In 2016, body region and modality service families with the most billed secondary interpretations were chest R&F (674,124), abdominal and pelvic R&F (65,566), brain CT (45,642), extremity R&F (34,560), abdominal and pelvic CT (14,269), and chest CT (10,914). All service families had secondary interpretation denial rates <25% in 2016 (15 service families, <10%). CONCLUSIONS:Among Medicare beneficiaries, the frequency of billed secondary interpretation services for diagnostic imaging services increased from 2003 to 2016 across a broad range of modalities and body regions, often dramatically. Payment denial rates were consistently low across service families. As CMS continues to seek input on appropriate coverage for these services, these findings suggest increasing clinical demand for and payer acceptance of these value-added radiologist services.

For many pathologies, early structural tissue changes occur at the cellular level, on the scale of micrometers or tens of micrometers. Magnetic resonance imaging (MRI) is a powerful non-invasive imaging tool used for medical diagnosis, but its clinical hardware is incapable of reaching the cellular length scale directly. In spite of this limitation, microscopic tissue changes in pathology can potentially be captured indirectly, from macroscopic imaging characteristics, by studying water diffusion. Here we focus on water diffusion and NMR relaxation in the human prostate, a highly heterogeneous organ at the cellular level. We present a physical picture of water diffusion and NMR relaxation in the prostate tissue, that is comprised of a densely-packed cellular compartment (composed of stroma and epithelium), and a luminal compartment with almost unrestricted water diffusion. Transverse NMR relaxation is used to identify fast and slow T

PURPOSE/OBJECTIVE:To conduct a meta-analysis of studies investigating discrepancy rates and clinical impact of imaging secondary interpretations and to identify factors influencing these rates. METHODS:EMBASE and PubMed databases were searched for original research investigations reporting discrepancy rates for secondary interpretations performed by radiologists for imaging examinations initially interpreted at other institutions. Two reviewers extracted study information and assessed study quality. Meta-analysis was performed. RESULTS:Twenty-nine studies representing a total of 12,676 imaging secondary interpretations met inclusion criteria; 19 of these studies provided data specifically for oncologic imaging examinations. Primary risks of bias included availability of initial interpretations, other clinical information, and reference standard before the secondary interpretation. The overall discrepancy rate of secondary interpretations compared with primary interpretations was 32.2%, including a 20.4% discrepancy rate for major findings. Secondary interpretations were management changing in 18.6% of cases. Among discrepant interpretations with an available reference standard, the secondary interpretation accuracy rate was 90.5%. The overall discrepancy rates by examination types were 28.3% for CT, 31.2% for MRI, 32.7% for oncologic imaging, 43.8% for body imaging, 39.9% for breast imaging, 34.0% for musculoskeletal imaging, 23.8% for neuroradiologic imaging, 35.5% for pediatric imaging, and 19.7% for trauma imaging. CONCLUSION/CONCLUSIONS:Most widely studied in the context of oncology, imaging secondary interpretations commonly result in discrepant interpretations that are management changing and more accurate than initial interpretations. Policymakers should consider these findings as they consider the value of, and payment for, secondary imaging interpretations.

PURPOSE: To characterize recent magnetic resonance imaging (MRI) technical development and innovation based on data regarding MRI-related patents awarded in 2016. METHODS: The US Patent and Trademark Office website was searched for patents awarded in 2016 and an abstract containing "magnetic resonance." Patent characteristics were summarized. An MRI physicist classified patents' themes. RESULTS: A total of 423 MRI-related patents were awarded in 2016. Among these, 29% had 1 inventor, 24% had 2 inventors, and 47% had >/=2 inventors. Mean interval between patents being filed and awarded was 1389 +/- 559 days (range: 167-4029). Most common countries of patents' first assignee were USA (40%), Germany (24%), Netherlands (10%), and Japan (10%). In all, 3% included assignees with different countries (most common collaborators USA and Germany). Patents' first assignee had an industry affiliation in 76% vs an academic affiliation in 21% (4% indeterminate); and 3% had industry-academia collaboration. Patents' most common themes were coils (n = 77), sequence design (n = 65), and noncoil scanner hardware (n = 41). These top themes were similar for USA, international, and industry-based patents; however, for academic-based patents, the most common themes were sequence design, reconstruction, and exogenous agents. Less common themes included image analysis, postprocessing, spectroscopy, relaxometry, diffusion, motion correction, radiation therapy, implants, wireless devices, and positron emission tomography-MRI. CONCLUSION: Most MRI-related patents were by non-US inventors. A large majority had industry affiliation; minimal industry-academic collaboration was observed. Patents from industry and academic inventors had distinct top focuses: hardware and software, respectively. Awareness of the most recent years' MRI patents may provide insights into forthcoming clinical translations and help guide ongoing research and entrepreneurism.

OBJECTIVE:The purpose of this study was to investigate county-level geographic patterns of mammographic screening uptake throughout the United States and to determine the impact of rural versus urban settings on breast cancer screening uptake. MATERIALS AND METHODS/METHODS:This descriptive study used County Health Rankings (CHR) data to identify the percentage of Medicare enrollees 67-69 years old per county who had at least one mammogram in 2013 or 2012 (uptake). Uptake was matched with U.S. Department of Agriculture (USDA) Atlas of Rural and Small Town America categorizations along a rural-urban continuum scale from 1 to 9 based on county population size (large urban, population ≥ 20,000 people; small urban, < 20,000 people) and proximity to a metropolitan area. Univariable and multivariable analyses were performed. RESULTS:In all, 2,243,294 Medicare beneficiaries were eligible for mammograms. National mean uptake per county was 60.5% (range, 26.0-86.0%). Uptake was significantly higher in metropolitan and large urban counties in 25 states and lower in only one. County-level mammographic uptake was moderately positively correlated with percentage of residents with some college education (r = 0.40, p < 0.001) and moderately negatively correlated with age-adjusted mortality (r = -0.41, p < 0.001). Multivariable analysis showed that percentage of white and black residents and age-adjusted mortality rate were the strongest significant independent predictors of uptake. CONCLUSION/CONCLUSIONS:Uptake of mammographic screening services in a Medicare population varies widely at the county level and is generally lowest in rural counties and urban counties with fewer than 20,000 people.

PURPOSE/OBJECTIVE:To assess trends in inferior vena cava (IVC) filter placement and retrieval procedures in Medicare beneficiaries over the last two decades. METHODS:Using Physician/Supplier Procedure Summary Master Files from 1994 through 2015, we calculated utilization rates for IVC filter placement and retrieval procedures in Medicare fee-for-service beneficiaries. Services were stratified by provider specialty group and site of service. RESULTS:IVC filter placement rates increased from 1994 to 2008 (from 65.0 to 202.1 per 100,000 beneficiaries, compound annual growth rate [CAGR] +8.4%) and then decreased to 128.9 by 2015 (CAGR -6.2%). This decrease was observed across all specialty groups and sites of service. From 1994 to 2015, placement procedure market share increased for radiologists (from 45.1% to 62.7%) and cardiologists (from 2.5% to 6.7%) but decreased for surgeons (from 46.6% to 27.9%). Overall, procedures shifted slightly from the inpatient (from 94.5% to 86.5% of all procedures) to outpatient hospital (from 4.9% to 14.9%) settings. Between 2012 and 2015, retrieval rates increased from 12.0 to 17.7 (CAGR +13.9%). Retrievals as a percentage of placement procedures were similar across specialties in 2015 (range 13.0%-13.8%). CONCLUSION/CONCLUSIONS:Despite prior dramatic growth, the utilization of IVC filters in Medicare beneficiaries markedly declined over the last decade, likely relating to evolving views regarding efficacy and long-term safety. This decline was accompanied by several filter-related market shifts, including increasing placement by radiologists and cardiologists, increasing outpatient placement procedures, and increasing retrieval rates.

PURPOSE/OBJECTIVE:As federal legislation increasingly influences health care delivery, the impact of election funding has grown. We aimed to characterize US radiologist federal political contributions over recent years. METHODS:After obtaining 2003 to 2016 finance data from the Federal Election Commission (FEC), we extracted contribution data for all self-identified radiologists. Contributions were classified by recipient group and FEC-designated political party and then analyzed temporally and geographically, in aggregate, and by individual radiologist. RESULTS:Between 2003 and 2016, the FEC reported 35,408,584 political contributions. Of these, 36,474 (totaling $16,255,099) were from 7,515 unique self-identified radiologists. Total annual radiologist contributions ranged from $480,565 in 2005 to $1,867,120 in 2012. On average, 1,697 radiologists made political contributions each year (range 903 in 2005 to 2,496 in 2016). On average, contributing radiologists gave $2,163 ± $4,053 (range $10-$121,836) over this time, but amounts varied considerably by state (range $865 in Utah to $4,325 in Arkansas). Of all radiologist dollars, 76.3% were nonpartisan, with only 14.8% to Republicans, 8.5% to Democrats, and 0.4% to others. Most radiologist dollars went to political action committees (PACs) rather than candidates (74.6% versus 25.4%). Those PAC dollars were overwhelmingly (92.5%) directed to the Radiology Political Action Committee (RADPAC), which saw self-identified radiologist contributions grow from $351,251 in 2003 to $1,113,966 in 2016. CONCLUSION/CONCLUSIONS:Radiologist federal political contributions have increased over 3-fold in recent years. That growth overwhelmingly represents contributions to RADPAC. Despite national political polarization, the overwhelming majority of radiologist political contributions are specialty-focused and nonpartisan.