Low-Volume and High-Volume Readers of Neurological and Musculoskeletal MRI: Achieving Subspecialization in Radiology

Abstract

Differentiate high versus low-volume radiologists who interpret neurological(Neuro) MRI or musculoskeletal(MSK) MRI, and measure the proportion of Neuro/MSK MRI read by low-volume radiologists. Methods: We queried the 2015 Medicare Physician and Other Supplier Public Use File for radiologists who submitted claims for Neuro or MSK MRI. Radiologists were classified as high-volume versus low-volume based on their work RVU(wRVU) focus and/or volume of studies interpreted using three different methodologies: (Method1) percentage of wRVU in Neuro/MSK MRI, (Method2) absolute number of Neuro/MSK MRI interpreted, and (Method3) both percentage and absolute number. Multiple thresholds with each methodology were tested, and the percent of Neuro/MSK MRI interpreted by low-volume radiologists was calculated for each threshold. Results: For Neuro(MSK) MRI 33%(50%) of studies were interpreted by a radiologist whose wRVU in Neuro/MSK MRI is less than 20% (Method1). With Method2, 22%(37%) of Neuro(MSK) MRI was interpreted by radiologists who read fewer than the mean number of Neuro/MSK MRI interpreted by an "average fulltime radiologist" whose wRVU in Neuro/MSK MRI is approximately 20%. With 1 Method3, 38%(57%) of Neuro(MSK) MRI was interpreted by "low-volume" radiologists. If instead, 50% wRVU threshold is used for Methods 1/2/3, 70%/ 58%/77% (86%/80%/90%) of Neuro(MSK) MRI is read by low-volume radiologists. Discussion: A large number of radiologists read a low volume of Neuro or MSK MRI; these low-volume Neuro/MSK MRI radiologists read a substantial portion of Neuro/MSK MRI. It is unknown which of the methods for distinguishing lowvolume radiologists, combined with which threshold may best correlate with high performing or low-performing radiologists.