Faculty Bibliography

PURPOSE/OBJECTIVE:Prostate multiparametric magnetic resonance imaging (mpMRI) has utility in detecting post-radiotherapy local recurrence. We conducted a multireader study to evaluate the diagnostic performance of mpMRI for local recurrence after low dose rate (LDR) brachytherapy. METHODS:A total of 19 patients with biochemical recurrence after LDR brachytherapy underwent 3T endorectal coil mpMRI with T2-weighted imaging, dynamic contrast-enhanced imaging (DCE) and diffusion-weighted imaging (DWI) with pathologic confirmation. Prospective reads by an experienced prostate radiologist were compared with reads from 4 radiologists of varying experience. Readers identified suspicious lesions and rated each MRI detection parameter. MRI-detected lesions were considered true-positive with ipsilateral pathologic confirmation. Inferences for sensitivity, specificity, positive predictive value (PPV), kappa, and index of specific agreement were made with the use of bootstrap resampling. RESULTS:Pathologically confirmed recurrence was found in 15 of 19 patients. True positive recurrences identified by mpMRI were frequently located in the transition zone (46.7%) and seminal vesicles (30%). On patient-based analysis, average sensitivity of mpMRI was 88% (standard error [SE], 3.5%). For highly suspicious lesions, specificity of mpMRI was 75% (SE, 16.5%). On lesion-based analysis, the average PPV was 62% (SE, 6.7%) for all lesions and 78.7% (SE, 10.3%) for highly suspicious lesions. The average PPV for lesions invading the seminal vesicles was 88.8% (n=13). The average PPV was 66.6% (SE, 5.8%) for lesions identified with T2-weighted imaging, 64.9% (SE, 7.3%) for DCE, and 70% (SE, 7.3%) for DWI. CONCLUSION/CONCLUSIONS:This series provides evidence that mpMRI after LDR brachytherapy is feasible with a high patient-based cancer detection rate. Radiologists of varying experience demonstrated moderate agreement in detecting recurrence.

As societal stakeholders call for increased evidence-based health policy, considerable attention has focused on Medicare, the country's largest payer. Concurrently, medical imaging has come under considerable scrutiny as a contributor to rising health care expenditures. Accordingly, many recent studies have focused on multiple factors related to the utilization of imaging among Medicare beneficiaries. This article summarizes several national Medicare fee-for-service data sources relevant to supporting ongoing investigations. Aggregated 100% data sets include the Physician/Supplier Procedure Summary Master Files and the Medicare Provider Utilization and Payment Data: Physician and Other Supplier Public Use File. The former focuses on services, specialties, and sites of service; the latter focuses on providers. Both permit high-level national assessments of imaging utilization and spending. Individual 5% random-sample claims-level data sources include the Carrier Standard Analytical File Limited Data Set and the Research Identifiable File, which contain greater beneficiary-level information. Both facilitate more robust patient- and encounter-level analyses and some assessment of downstream outcomes but involve greater costs and require greater privacy oversight. More recently, Medicare data are being merged with registry data (eg, Surveillance, Epidemiology, and End Results-Medicare Linked Database files), creating opportunities for even more robust analyses given richer clinical information. Understanding these data sets and trade-offs in their use will aid policy-focused imaging health services researchers in most effectively conducting their investigations.

PURPOSE: To evaluate the impact of questionnaires completed by patients at the time of abdominopelvic CT performed for abdominal pain on the completeness of clinical information and the identification of potential causes of pain, compared with order requisitions alone. METHODS: 100 outpatient CT examinations performed for the evaluation of abdominal pain were retrospectively reviewed. The specificity of the location of pain was compared between the order requisition and patient questionnaire. An abdominal imaging fellow (Reader 1) and abdominal radiologist (Reader 2) reviewed the examinations independently in two sessions 6 weeks apart (one with only the order requisition and one also with the questionnaire). Readers recorded identified causes of pain and rated their confidence in interpretation (1-5 scale; least to greatest confidence). RESULTS: In 30% of patients, the questionnaire provided a more specific location for pain. Among these, the pain was localized to a specific quadrant in 40%. With having access to the questionnaire, both readers identified additional causes for pain not identified in session 1 (Reader 1, 8.6% [7/81]; Reader 2 5.3% [4/75]). Additional identified causes of pain included diverticulitis, cystitis, peritoneal implants, epiploic appendagitis, osseous metastatic disease, umbilical hernia, gastritis, and SMA syndrome. Confidence in interpretation was significantly greater using the questionnaire for both readers (Reader 1: 4.8 +/- 0.6 vs. 4.0 +/- 0.5; Reader 2: 4.9 +/- 0.3 vs. 4.7 +/- 0.5, p < 0.001). CONCLUSION: Patient questionnaires provide additional relevant clinical history, increased diagnostic yield, and improve radiologists' confidence. Radiology practices are encouraged to implement questionnaires and make these readily available to radiologists at the time of interpretation.

RATIONALE AND OBJECTIVES: To characterize online news coverage relating to mammography, including articles' stance toward screening mammography. MATERIALS AND METHODS: Google News was used to search U.S. news sites over a 9-year period (2006-2015) based on the search terms "mammography" and "mammogram." The top 100 search results were recorded. Identified articles were manually reviewed. RESULTS: The top 100 news articles were from the following sources: local news outlet (50%), national news outlet (24%), nonimaging medical source (13%), entertainment or culture news outlet (6%), business news outlet (4%), peer-reviewed journal (1%), and radiology news outlet (1%). Most common major themes were the screening mammography controversy (29%), description of a new breast imaging technology (23%), dense breasts (11%), and promotion of a public screening initiative (11%). For the most recent year, article stance toward screening mammography was 59%, favorable; 16%, unfavorable; and 25%, neutral. After 2010, there was an abrupt shift in articles' stances from neutral to both favorable and unfavorable. CONCLUSIONS: A wide range of online news sources addressed a range of issues related to mammography. National, rather than local, news sites were more likely to focus on the screening controversy and more likely to take an unfavorable view. The controversial United States Preventive Services Task Force guidelines may have influenced articles to take a stance on screening mammography. As such online news may impact public perception of the topic and thus potentially impact guideline adherence, radiologists are encouraged to maintain awareness of this online coverage and to support the online dissemination of reliable and accurate information.

RATIONALE AND OBJECTIVES: This study aimed to assess a novel method of three-dimensional (3D) co-registration of prostate magnetic resonance imaging (MRI) examinations performed before and after prostate cancer focal therapy. MATERIALS AND METHODS: We developed a software platform for automatic 3D deformable co-registration of prostate MRI at different time points and applied this method to 10 patients who underwent focal ablative therapy. MRI examinations were performed preoperatively, as well as 1 week and 6 months post treatment. Rigid registration served as reference for assessing co-registration accuracy and precision. RESULTS: Segmentation of preoperative and postoperative prostate revealed a significant postoperative volume decrease of the gland that averaged 6.49 cc (P = .017). Applying deformable transformation based on mutual information from 120 pairs of MRI slices, we refined by 2.9 mm (max. 6.25 mm) the alignment of the ablation zone, segmented from contrast-enhanced images on the 1-week postoperative examination, to the 6-month postoperative T2-weighted images. This represented a 500% improvement over the rigid approach (P = .001), corrected by volume. The dissimilarity by Dice index of the mapped ablation zone using deformable transformation vs rigid control was significantly (P = .04) higher at the ablation site than in the whole gland. CONCLUSIONS: Our findings illustrate our method's ability to correct for deformation at the ablation site. The preliminary analysis suggests that deformable transformation computed from mutual information of preoperative and follow-up MRI is accurate in co-registration of MRI examinations performed before and after focal therapy. The ability to localize the previously ablated tissue in 3D space may improve targeting for image-guided follow-up biopsy within focal therapy protocols.

OBJECTIVE:Radiologic technologists may repeat images within a radiographic examination because of perceived suboptimal image quality, excluding these original images from submission to a PACS. This study assesses the appropriateness of technologists' decisions to repeat musculoskeletal and chest radiographs as well as the utility of repeat radiographs in addressing examinations' clinical indication. MATERIALS AND METHODS/METHODS:We included 95 musculoskeletal and 87 chest radiographic examinations in which the technologist repeated one or more images because of perceived image quality issues, rejecting original images from PACS submission. Rejected images were retrieved from the radiograph unit and uploaded for viewing on a dedicated server. Musculoskeletal and chest radiologists reviewed rejected and repeat images in their timed sequence, in addition to the studies' remaining images. Radiologists answered questions regarding the added value of repeat images. RESULTS:The reviewing radiologist agreed with the reason for rejection for 64.2% of musculoskeletal and 60.9% of chest radiographs. For 77.9% and 93.1% of rejected radiographs, the clinical inquiry could have been satisfied without repeating the image. For 75.8% and 64.4%, the repeated images showed improved image quality. Only 28.4% and 3.4% of repeated images were considered to provide additional information that was helpful in addressing the clinical question. CONCLUSION/CONCLUSIONS:Most repeated radiographs (chest more so than musculoskeletal radiographs) did not add significant clinical information or alter diagnosis, although they did increase radiation exposure. The decision to repeat images should be made after viewing the questionable image in context with all images in a study and might best be made by a radiologist rather than the performing technologist.

OBJECTIVE: The purpose of this study is to assess informal consultations between radiologists and referring physicians as identified through an electronic medical record (EMR) search. MATERIALS AND METHODS: The EMR was searched for physician notes containing either the term "radiologist" or "radiology" in combination with any of the following: "second opinion," "second-opinion," "2nd opinion," "2nd-opinion," "rereview," "re-review," "reread," "re-read," "overread," "over-read," "spoke with," "discussed with," or "reviewed with." A sample of 300 notes describing a consultation by a referring physician with a diagnostic radiologist was identified. RESULTS: Of the consultations, 73.3% were related to a specific previously interpreted imaging study, and 26.7% were related to other general management issues, including patient safety. Only 18.7% of the physicians' notes indicated the name of the consulted radiologist; a fraction of these consultations were with a radiologist other than the one who originally interpreted the study or with a radiologist at an outside institution. Of consultations with a local radiologist regarding a specific prior examination, 33.9% resulted in a new finding, a change in severity of a previously detected finding, or a change in management recommendation. Of consultations with a change from the initial report, 24.6% were documented by the radiologist via an addendum; 92.9% of these addenda agreed with the referring physicians' notes. CONCLUSION: Radiologists may be unaware of how their consultations are captured within physician notes that may be incomplete or misrepresent the communication. Radiology practices should consider developing policies requiring radiologists to document informal consultations potentially affecting patient management, while developing solutions to facilitate such documentation when it is not readily achieved through report addenda (e.g., through direct documentation by the radiologist in the EMR).

PURPOSE: The aim of this study was to assess both existing Medicare provider code assignments and a new claims-based system for subspecialty classification of private practice radiologists. METHODS: Websites of the 100 largest US radiology private practices were used to identify 1,476 radiologists self-identified with a single subspecialty ([1] abdominal, [2] breast, [3] cardiothoracic, or [4] musculoskeletal imaging; [5] nuclear medicine; [6] interventional radiology; [7] neuroradiology). Concordance of existing Medicare radiology subspecialty provider codes (present only for nuclear medicine and interventional radiology) was first assessed. Next, using a classification approach based on Neiman Imaging Types of Service (NITOS) piloted among academic practices, the percentage of subspecialty work relative value units (wRVUs) from 2012 to 2014 Medicare claims were used to assign each radiologist a unique subspecialty. RESULTS: Existing Medicare provider codes matched only 8.0% of nuclear medicine physicians and 10.7% of interventional radiologists to their self-reported subspecialties. The NITOS-based system mapped a median 51.9% of private practice radiologists' wRVUs to self-identified subspecialties (range, 23.3% [nuclear medicine] to 73.6% [neuroradiology]). The 50% NITOS-based wRVU threshold previously established for academic radiologists correctly assigned subspecialties to 48.8% of private practice radiologists but incorrectly categorized 2.9%. Practice patterns of the remaining 48.3% were sufficiently varied such that no single subspecialty assignment was possible. CONCLUSIONS: Existing Medicare provider codes poorly mirror subspecialty radiologists' own practice website-designated subspecialties. Actual payer claims data permit far more granular and accurate subspecialty identification for many radiologists. As new payment models increasingly focus on subspecialty-specific performance measures, claims-based identification methodologies show promise for reproducibly and transparently matching radiologists to practice-relevant metrics.

PURPOSE: To identify factors associated with list price variation for radiologists' services. METHODS: The 2014 Medicare Physician and Other Supplier Public Use File was used to identify submitted charges ("list prices") and payments for radiologists' services (ie, not hospital service charges). Charge-to-payment ratios were computed for individual radiologists as a measure of excess charges. Numerous radiologist-level factors identifiable using publicly available data sets were explored. RESULTS: Among 26,715 radiologists nationally, the mean charge-to-payment ratio was 4.2 +/- 2.0. A greater charge-to-payment ratio was most strongly predicted for those serving higher-complexity patients (ratio ranging from 3.8 +/- 1.8 to 4.1 +/- 1.6 for radiologists in the first through third quartiles in terms of patient complexity, compared with a ratio of 4.8 +/- 2.8 for radiologists in the highest quartile in terms of patient complexity). A higher charge-to-payment ratio was also observed among those with, rather than without, a teaching institutional affiliation (4.7 +/- 2.8 versus 4.0 +/- 1.8, respectively) and among subspecialists rather than generalists (4.4 +/- 2.5 versus 3.9 +/- 1.5, respectively). Among subspecialties, charge-to-payment ratios ranged from 3.3 +/- 1.3 (breast imaging) to 5.7 +/- 4.1 (interventional radiology). Charge-to-payment ratios showed weak inverse correlations with total service volume (r = -0.13) and total payments (r = -0.11). CONCLUSION: Distinct from hospital prices and historically considered arbitrary, higher charges for radiologists' services demonstrate consistent patterns of variation and are most strongly seen for those serving higher complexity patients. As price transparency initiatives expand, radiologists should be aware of how and why their list prices compare with local and national benchmarks.