Faculty Bibliography

PURPOSE: To evaluate whole-lesion ADC histogram metrics for assessing the malignant potential of pancreatic intraductal papillary mucinous neoplasms (IPMNs), including in comparison with conventional MRI features. METHODS: Eighteen branch-duct IPMNs underwent MRI with DWI prior to resection (n = 16) or FNA (n = 2). A blinded radiologist placed 3D volumes-of-interest on the entire IPMN on the ADC map, from which whole-lesion histogram metrics were generated. The reader also assessed IPMN size, mural nodularity, and adjacent main-duct dilation. Benign (low-to-intermediate grade dysplasia; n = 10) and malignant (high-grade dysplasia or invasive adenocarcinoma; n = 8) IPMNs were compared. RESULTS: Whole-lesion ADC histogram metrics demonstrating significant differences between benign and malignant IPMNs were: entropy (5.1 +/- 0.2 vs. 5.4 +/- 0.2; p = 0.01, AUC = 86%); mean of the bottom 10th percentile (2.2 +/- 0.4 vs. 1.6 +/- 0.7; p = 0.03; AUC = 81%); and mean of the 10-25th percentile (2.8 +/- 0.4 vs. 2.3 +/- 0.6; p = 0.04; AUC = 79%). The overall mean ADC, skewness, and kurtosis were not significantly different between groups (p >/= 0.06; AUC = 50-78%). For entropy (highest performing histogram metric), an optimal threshold of >5.3 achieved a sensitivity of 100%, a specificity of 70%, and an accuracy of 83% for predicting malignancy. No significant difference (p = 0.18-0.64) was observed between benign and malignant IPMNs for cyst size >/=3 cm, adjacent main-duct dilatation, or mural nodule. At multivariable analysis of entropy in combination with all other ADC histogram and conventional MRI features, entropy was the only significant independent predictor of malignancy (p = 0.004). CONCLUSION: Although requiring larger studies, ADC entropy obtained from 3D whole-lesion histogram analysis may serve as a biomarker for identifying the malignant potential of IPMNs, independent of conventional MRI features.

OBJECTIVE: To determine how ipsilateral (ipsi) and contralateral (contra) systematic biopsies (SB) impacts detection of clinically significant versus insignificant prostate cancer (PCa) in men with unilateral MRI lesion undergoing MRI fusion target biopsy (MRF-TB). MATERIALS AND METHODS: 211 cases with one unilateral MRI lesion were subjected to SB and MRF-TB. Biopsy tissue cores from the MRF-TB, ipsi-SB and contra-SB were analyzed separately. RESULTS: A direct relationship was observed between MRI suspicious score (SS) and detection of any cancer, Gleason 6 PCa and Gleason > 6 PCa. MRF-TB alone, MRF-TB + ipsi-SB and MRF-TB + contra-SB detected 64.1%, 89.1% and 76.1% of all PCa, respectively, 53.5%, 81.4% and 69.8% of Gleason 6 PCa, respectively, and 73.5%, 96.0% and 81.6% of Gleason >6 PCa, respectively. MRF-TB + ipsi-SB detected 96% of clinically significant PCa and avoided detection of 18.6% of clinically insignificant PCa. MRF-TB + contra-SB detected 81.6% of clinically significant PCa and avoided detection of 30.2% of clinically insignificant PCa. CONCLUSION: Our study suggests that ipsi-SB should be added to MRF-TB as detection of clinically significant PCa increases with only a modest increase in clinically insignificant PCa detection. Contra-SB in this setting may be deferred since it primarily detects clinically insignificant PCa.

The annual cost of healthcare delivery in the USA now exceeds US$3 trillion. Fee for service methodology is often implicated as a cause of this exceedingly high figure. The Affordable Care Act created the Center for Medicare and Medicaid Innovation (CMMI) to pilot test value based alternative payments for reimbursing physician services. In 2015, the Medicare Access and CHIP Reauthorization Act (MACRA) was passed into law. MACRA has dramatic implications for all US based healthcare providers. MACRA permanently repealed the Medicare Sustainable Growth Rate so as to stabilize physician part B Medicare payments, consolidated pre-existing federal performance programs into the Merit based Incentive Payments System (MIPS), and legislatively mandated new approaches to paying clinicians. Neurointerventionalists will predominantly participate in MIPS. MIPS unifies, updates, and streamlines previously existing federal performance programs, thereby reducing onerous redundancies and overall administrative burden, while consolidating performance based payment adjustments. While MIPS may be perceived as a straightforward continuation of fee for service methodology with performance modifiers, MIPS is better viewed as a stepping stone toward eventually adopting alternative payment models in later years. In October 2016, the Centers for Medicare and Medicaid Services (CMS) released a final rule for MACRA implementation, providing greater clarity regarding 2017 requirements. The final rule provides a range of options for easing MIPS reporting requirements in the first performance year. Nonetheless, taking the newly offered 'minimum possible' approach toward meeting the requirements will still have negative consequences for providers.

OBJECTIVE: The purpose of this study was to apply a visual assessment of the intensity and pattern of T1 hyperintensity at MRI to differentiate hemorrhagic renal cysts from renal cell carcinoma (RCC). MATERIALS AND METHODS: A total of 144 T1-hyperintense renal lesions (62 cysts, all showing no enhancement on subtracted contrast-enhanced images and either 2-year stability or unenhanced CT density > 70 HU, and 82 histologically confirmed RCCs) in 144 patients were included. Two radiologists independently characterized qualitative features of the T1 hyperintensity in each lesion on unenhanced T1-weighted images. An additional radiologist placed ROIs to measure lesions' T1 signal intensity normalized to that of the psoas muscle. Chi-square and unpaired t tests were performed to compare the pattern of T1 hyperintensity between groups. RESULTS: The T1 hyperintensity was considered marked in 62.9% of cysts and 17.1% of RCCs for reader 1 and in 46.8% of cysts and 8.5% of RCCs for reader 2 (p < 0.001). The T1 hyperintensity exhibited a diffusely homogeneous distribution in 88.7% of cysts and 7.3% of RCCs for reader 1 and in 72.6% of cysts and 4.9% of RCCs for reader 2 (p < 0.001). The combination of both diffusely homogeneous distribution and marked degree of T1 hyperintensity achieved sensitivities of 40.3-56.5%, specificities of 97.6-98.8%, and accuracies of 73.6-79.9% for the diagnosis of T1-hyperintense cysts. The two cases of RCC exhibiting this imaging pattern for at least one reader were both papillary RCCs. Normalized signal intensity was 2.39 +/- 0.99 in T1-hyperintense cysts versus 2.12 +/- 0.84 in T1-hyperintense RCCs (p = 0.088). CONCLUSION: Diffuse T1 hyperintensity, particularly when marked, strongly indicates a hemorrhagic cyst rather than an RCC. Deferral of follow-up imaging may be considered when this imaging appearance is encountered at unenhanced MRI.

PURPOSE: The Internet provides a potentially valuable mechanism for radiology practices to communicate with patients and enhance the patient experience. The aim of this study was to assess the websites of US radiology private practices, with attention to the frequency of content of potential patient interest. METHODS: The 50 largest private practice radiology facilities in the United States were identified from RadiologyBusiness.com. Websites were reviewed for information content and functionality. RESULTS: Content regarding radiologists' names, medical schools, residencies, fellowships, photographs, and board certification status; contact for billing questions; and ability to make online payments was present on 80% to 98% of sites. Content regarding examination preparation, contrast use, examination duration, description of examination experience, scheduling information, directions, privacy policy, radiologists' role in interpretation, and ACR accreditation was present on 60% to 78%. Content regarding accepted insurers, delivery of results to referrers, report turnaround times, radiologists' years of experience, radiation safety, and facility hours was present on 40% to 58%. Content regarding technologist certification, registration forms, instructions for requesting a study on disc, educational videos, and patient testimonials was present on 20% to 38%. Content regarding examination prices, patient satisfaction scores, peer review, online scheduling, online report and image access, and parking was present on <20%. CONCLUSIONS: Radiology practices' websites most frequently provided information regarding their radiologists' credentials, as well as billing and payment options. Information regarding quality, safety, and the examination experience, as well as non-payment-related online functionality, was less common. These findings regarding the most common deficiencies may be useful for radiology practices in expanding their websites' content, thereby improving communication and potentially the patient experience.

OBJECTIVE: Our aim was to evaluate the frequency and outcomes of incidental breast lesions detected on abdominal MRI examinations. MATERIALS AND METHODS: Abdominal MRI reports for 11,462 women imaged at our institution from November 2007 through December 2014 were reviewed to identify those reporting an incidental breast lesion. Available breast imaging and pathology results were assessed to identify outcomes in these lesions. RESULTS: Incidental breast lesions were described in the MRI reports of 292 (3%) patients who underwent abdominal MRI during the study period; breast imaging was recommended for 192 of these 292 (66%) patients. Sixty-three of the 192 (33%) patients for whom follow-up breast imaging was recommended underwent such imaging at our institution. Twenty-one of these 63 (33%) lesions underwent biopsy or surgery; histologic sampling of these lesions yielded seven incidental cancers (invasive ductal, n = 6; invasive lobular, n = 1) and 14 benign diagnoses. Three additional cancers (invasive ductal, n = 2; invasive lobular, n = 1) and three benign diagnoses were discovered at pathology at outside institutions. Of the remaining 165 patients without a histologic diagnosis, the lesions in 95 (58%) patients were presumed to be benign because of stability over time. Seven of the 10 patients with a diagnosis of incidental cancer (age range, 53-86 years; mean +/- SD, 67.0 +/- 10.6 years) had not undergone screening mammography at our institution. The frequency of incidental breast cancer was 11% of patients subsequently undergoing follow-up breast imaging at our institution, 3% of all patients with reported breast lesions, and 0.09% of patients undergoing abdominal MRI examinations. CONCLUSION: Although incidental breast lesions were rarely detected on abdominal MRI, a considerable number of these lesions were found to represent breast cancer, particularly when leading to a recommendation for follow-up breast imaging. Therefore, it is important for radiologists interpreting abdominal MRI examinations to carefully evaluate for the presence of breast abnormalities.

PURPOSE: The aim of this study was to conduct a prospective pilot study comparing the diagnostic performance of MRI alone and F-FDG simultaneous PET/MRI using a diuresis protocol in bladder cancer patients. METHODS: Twenty-two bladder cancer patients underwent F-FDG PET/MRI, using intravenous furosemide and oral hydration for bladder clearance. A radiologist scored probability of tumor in 3 locations (urinary bladder, pelvic lymph nodes, nonnodal pelvis) using 1- to 3-point scale (1 = negative, 2 = equivocal, 3 = definite tumor). A nuclear medicine physician reviewed fused PET/MRI images, after which scores were reassigned based on combined findings. Follow-up pathologic and imaging data served as reference. Performances of MRI alone and PET/MRI were compared. RESULTS: Of these patients, 82%, 38%, and 18% were positive for bladder, pelvic nodal, and nonnodal pelvic tumor, respectively. At a score of 3, PET/MRI exhibited greater accuracy for detection of bladder tumor (86% vs 77%), metastatic pelvic lymph nodes (95% vs 76%), and nonnodal pelvic malignancy (100% vs 91%). In the bladder, PET changed the level of suspicion in 36% of patients (50% increased suspicion, 50% decreased suspicion), with 75% of these changes deemed correct based on reference standard. For pelvic lymph nodes, PET changed suspicion in 52% (36% increase, 64% decrease), with 95% of changes deemed correct. For nonnodal pelvis, PET changed suspicion in 9% (100% increase), with 100% deemed correct. CONCLUSIONS: Additional PET information helped to appropriately determine level of suspicion in multiple anatomic sites for otherwise equivocal findings on MRI alone. Although requiring larger studies, findings suggest a possible role for simultaneous PET/MRI to assist bladder cancer management.

Purpose To test the impact of existing Prostate Imaging Reporting and Data System (PI-RADS) version 2 (V2) decision rules, as well as of proposed adjustments to these decision rules, on detection of Gleason score (GS) 7 or greater (GS >/=7) prostate cancer. Materials and Methods Two radiologists independently provided PI-RADS V2 scores for the dominant lesion on 343 prostate magnetic resonance (MR) examinations. Diagnostic performance for GS >/=7 tumor was assessed by using MR imaging-ultrasonography fusion-targeted biopsy as the reference. The impact of existing PI-RADS V2 decision rules, as well as a series of exploratory proposed adjustments, on the frequency of GS >/=7 tumor detection, was evaluated. Results A total of 210 lesions were benign, 43 were GS 6, and 90 were GS >/=7. Lesions were GS >/=7 in 0%-4.1% of PI-RADS categories 1 and 2, 11.4%-27.1% of PI-RADS category 3, 44.4%-49.3% of PI-RADS category 4, and 72.1%-73.7% of PI-RADS category 5 lesions. PI-RADS category 4 or greater had sensitivity of 78.9%-87.8% and specificity of 75.5%-79.1 for detecting GS >/=7 tumor. The frequency of GS >/=7 tumor for existing PI-RADS V2 decision rules was 30.0%-33.3% in peripheral zone (PZ) lesions upgraded from category 3 to 4 based on dynamic contrast enhancement (DCE) score of positive; 50.0%-66.7% in transition zone (TZ) lesions upgraded from category 3 to 4 based on diffusion-weighted imaging (DWI) score of 5; and 71.7%-72.7% of lesions in both zones upgraded from category 4 to 5 based on size of 15 mm or greater. The frequency of GS >/=7 tumor for proposed adjustments to the decision rules was 30.0%-60.0% for TZ lesions upgraded from category 3 to 4 based on DWI score of 4; 33.3%-57.1% for TZ lesions upgraded from category 3 to 4 based on DCE score of positive when incorporating new criteria (unencapsulated sheetlike enhancement) for DCE score of positive in TZ; and 56.4%-61.9% for lesions in both zones upgraded from category 4 to 5 based on size of 10-14 mm. Other proposed adjustments yielded GS >/=7 tumor in less than 15% of cases for one or more readers. Conclusion Existing PI-RADS V2 decision rules exhibited reasonable performance in detecting GS >/=7 tumor. Several proposed adjustments to the criteria (in TZ, upgrading category 3 to 4 based on DWI score of 4 or modified DCE score of positive; in PZ or TZ, upgrading category 4 to 5 based on size of 10-14 mm) may also have value for this purpose. (c) RSNA, 2016 Online supplemental material is available for this article.

PURPOSE: The aim of this study was to evaluate the feasibility of using Twitter polls to assess public opinion regarding session content at a national specialty society meeting. METHODS: Twitter polls allow users to embed multiple-choice questions within tweets and automatically aggregate responses. Two radiologists attending the 2016 annual meeting of the ACR posted a Twitter poll containing the hashtag #ACR2016 during 10 meeting sessions addressing socioeconomics/advocacy, patient experience, and social media/informatics (20 polls total). Each poll contained a question asking for an opinion regarding the session's content. Polls were open for responses for 24 hours. RESULTS: The average number of responses per poll was significantly higher for the user with the larger number of Twitter followers (24.3 +/- 14.4 versus 11.2 +/- 9.8, P = .015). A total of 57% of respondents agreed that radiologists' payments should shift to value-based payments, and 86% agreed that radiologists should routinely survey their patients to monitor quality; however, 83% disagreed with basing physician payments on patient satisfaction scores. A total of 85% disagreed that the artificial intelligence supercomputer Watson will entirely replace radiologists. A total of 76% agreed that social media can drive business at less cost than standard marketing. A total of 56% agreed with the direction of the ACR's advocacy and regulatory efforts, whereas 74% considered the ACR's advocacy efforts to be moderately or very useful for their practice. A total of 50% planned to change their practice on the basis of keynote remarks by Dr Ezekiel Emanuel. CONCLUSIONS: Twitter polls provide a free and easy infrastructure to potentially capture global public sentiment during the course of a medical society meeting. Their use may enrich and promote discussions of key session content.