Faculty Bibliography

BACKGROUND:Hearing preservation is a goal for many patients with vestibular schwannoma. We examined pretreatment magnetic resonance imaging (MRI) and posttreatment hearing outcome after stereotactic radiosurgery. METHODS:From 2004 to 2014, a cohort of 125 consecutive patients with vestibular schwannoma (VS) treated via stereotactic radiosurgery (SRS) were retrospectively reviewed. MRIs containing three-dimensional constructive interference in steady state or equivalent within 1 year before treatment were classified by two radiologists for pretreatment characteristics. "Good" hearing was defined as American Academy of Otolaryngology-Head and Neck Surgery class A. Poor hearing outcome was defined as loss of good pretreatment hearing after stereotactic radiosurgery. RESULTS:Sixty-one patients met criteria for inclusion. Most had tumors in the distal internal auditory canal (55%), separated from the brainstem (63%), oval shape (64%) without cysts (86%), and median volume of 0.85 ± 0.55 cm. Pretreatment audiograms were performed a median of 108 ± 173 days before stereotactic radiosurgery; 38% had good pretreatment hearing. Smaller tumor volume (p < 0.005) was the only variable associated with good pretreatment hearing. 49 (80%) patients had posttreatment audiometry, with median follow-up of 197 ± 247 days. Asymmetrically decreased pretreatment cochlear CISS signal on the side of the VS was the only variable associated with poor hearing outcome (p = 0.001). Inter-rater agreement on cochlear three-dimensional constructive interference in steady state preservation was 91%. CONCLUSIONS:Decreased cochlear CISS signal may indicate a tumor's association with the cochlear neurovascular bundle, influencing endolymph protein concentration and creating an inability to preserve hearing. This important MRI characteristic can influence planning, counseling, and patient selection for vestibular schwannoma treatment.

Purpose To compare standard diffusion-weighted (DW) imaging and diffusion kurtosis (DK) imaging for prostate cancer (PC) detection and characterization in a large patient cohort, with attention to the potential added value of DK imaging. Materials and Methods This retrospective institutional review board-approved study received a waiver of informed consent. Two hundred eighty-five patients with PC underwent 3.0-T phased-array coil prostate magnetic resonance (MR) imaging, including a DK imaging sequence (b values 0, 500, 1000, 1500, and 2000 sec/mm2) before prostatectomy. Maps of apparent diffusion coefficient (ADC) and diffusional kurtosis (K) were derived by using maximal b values of 1000 and 2000 sec/mm2, respectively. Mean ADC and K were obtained from volumes of interest (VOIs) placed on each patient's dominant tumor and benign prostate tissue. Metrics were compared between benign and malignant tissue, between Gleason score (GS) /= 3 + 4 tumors, and between GS /= 4 + 3 tumors by using paired t tests, analysis of variance, receiver operating characteristic (ROC) analysis, and exact tests. Results ADC and K showed significant differences for benign versus tumor tissues, GS /= 3 + 4 tumors, and GS /= 4 + 3 tumors (P < .001 for all). ADC and K were highly correlated (r = -0.82; P < .001). Area under the ROC curve was significantly higher (P = .002) for ADC (0.921) than for K (0.902) for benign versus malignant tissue but was similar for GS /= 3 + 4 tumors (0.715-0.744) and GS /= 4 + 3 tumors (0.694-0.720) (P > .15). ADC and K were concordant for these various outcomes in 80.0%-88.6% of patients; among patients with discordant results, ADC showed better performance than K for GS /= 4 + 3 tumors (P = .016) and was similar to K for other outcomes (P > .136). Conclusion ADC and K were highly correlated, had similar diagnostic performance, and were concordant for the various outcomes in the large majority of cases. These observations did not show a clear added value of DK imaging compared with standard DW imaging for clinical PC evaluation. (c) RSNA, 2017 Online supplemental material is available for this article.

Purpose: Medical societies are incorporating Twitter to communicate with their members and connect with patients. This study compares the online presence of 3 major oncologic societies. Methods and materials: All available tweets in 2014 by the American Society for Radiation Oncology (ASTRO), American Society of Clinical Oncology (ASCO), and Society of Surgical Oncology (SSO) were collected. We analyzed whether posts were original content or retweets. The monthly tweet rate was followed to assess trends. We created 2 new metrics, supporter ratio and tweet density, to correlate online presence and engagement with offline membership breadth. The supporter ratio is the number of people following the organization divided by the number of registered members of each society. The tweet density is the total number of posts divided by the number of registered members of each society. Results: In February 2015, ASCO, ASTRO, and SSO had 36,385; 10,899; and 2721 members, respectively. ASCO's Twitter handle had 33,974 followers, with a supporter ratio of 0.93. A total of 2563 original tweets and 1416 retweets were estimated, which represents a tweet density of 0.11. @ASTRO_org had 5445 followers and a supporter ratio of 0.50. In 2014, ASTRO posted 415 original content tweets and 9 retweets, with a tweet density of 0.039. SSO had a supporter ratio of 0.91 on the basis of 2481 followers. In 2014, SSO posted 207 original tweets and 190 retweets, with a tweet density of 0.15. An increase in tweets and retweets was seen during the month of each society's annual meeting. ASTRO's 61% increase in September 2014 was smaller than SSO's 462% and ASCO's 84%. Conclusion: ASTRO's use of Twitter lags behind ASCO and SSO. Although all 3 societies show increased Twitter use during their annual meetings, they should work toward more meaningful engagement throughout the year. The new metrics of tweet density and supporter ratio will serve as benchmarks for member engagement in future studies.

PURPOSE: To assess the impact of patient race and age on the performance of apparent diffusion coefficient (ADC) values for assessment of prostate cancer aggressiveness. MATERIALS AND METHODS: 457 prostate cancer patients who underwent 3T phased-array coil prostate MRI including diffusion-weighted imaging (DWI; maximal b-value 1000 s/mm2) before prostatectomy were included. Mean ADC of a single dominant lesion was measured in each patient, using histopathologic findings from the prostatectomy specimen as reference. In subsets defined by race and age, ADC values were compared between Gleason score (GS) /= 4 + 3 tumors. RESULTS: 81% of patients were Caucasian, 12% African-American, 7% Asian-American. 13% were <55 years, 42% 55-64 years, 41% 65-74 years, and 4% >/=75 years. 63% were GS /= 4 + 3. ADC was significantly lower in GS >/= 4 + 3 tumors than in GS /= 4 + 3 as well as optimal ADC threshold was Caucasian: 0.73//=75 years, 0.79//=75 years than <55 years or 55-64 years (100.0% vs. 53.6%-73.3%; P < 0.001). CONCLUSION: Patients' race and age may impact the diagnostic performance and optimal threshold when applying ADC values for evaluation of prostate cancer aggressiveness.

To use Twitter to assess the immediate public response to the United States Preventive Services Task Force (USPSTF) 2013 draft guidelines on lung cancer screening with low-dose chest CT (LDCT). The number of tweets including the phrases "lung cancer screening," "lung CT," "chest CT," "low dose computed tomography," "low dose CT," or "LDCT" was recorded for 6 days before and after guidelines release. A systematic sample of 172 tweets from the week following release was coded for user type, tweet opinion, linked article source, and article opinion. Following guidelines' release, the number of daily tweets increased from 13 +/- 8 to 311 +/- 395. The 172 tweets in the week following release were tweeted by 166 unique users including: news organizations/online news gathering accounts (34.9%), general public (21.7%), physicians (12.0%, 6 radiologists), and businesses (11.4%). 23.3% of tweets provided opinion on the guidelines (50.0% favorable, 27.5% concerned toward screening). Most (91.3%) tweets contained links to a total of 46 unique articles, which were authored by lay press (41.3%), non-peer-reviewed medical press (32.6%), and hospital/medical practice websites (10.9%). Among these, 50.0% were favorable, citing mortality reduction (87.0%), published data supporting screening (50.0%), and early detection (43.5%), while 28.3% expressed concern, including false positives (58.9%) and radiation risk (39.1%). Twitter activity rose rapidly after the USPSTF draft guidelines on LDCT. Most users were non-physicians and frequently cited non-peer-reviewed articles. Users maintained an overall favorable view of screening, while expressing various concerns. Considerable opportunity exists for greater radiologist engagement in this online public dialog.

BACKGROUND AND PURPOSE: Preoperative localization of the pituitary gland with imaging in patients with macroadenomas has been inadequately explored. The pituitary gland enhancing more avidly than a macroadenoma has been described in the literature. Taking advantage of this differential enhancement pattern, our aim was to evaluate the role of high-resolution dynamic MR imaging with golden-angle radial sparse parallel reconstruction in localizing the pituitary gland in patients undergoing trans-sphenoidal resection of a macroadenoma. MATERIALS AND METHODS: A retrospective study was performed in 17 patients who underwent trans-sphenoidal surgery for pituitary macroadenoma. Radial volumetric interpolated brain examination sequences with golden-angle radial sparse parallel technique were obtained. Using an ROI-based method to obtain signal-time curves and permeability measures, 3 separate readers identified the normal pituitary gland distinct from the macroadenoma. The readers' localizations were then compared with the intraoperative location of the gland. Statistical analyses were performed to assess the interobserver agreement and correlation with operative findings. RESULTS: The normal pituitary gland was found to have steeper enhancement-time curves as well as higher peak enhancement values compared with the macroadenoma (P < .001). Interobserver agreement was almost perfect in all 3 planes (kappa = 0.89). In the 14 cases in which the gland was clearly identified intraoperatively, the correlation between the readers' localization and the true location derived from surgery was also nearly perfect (kappa = 0.95). CONCLUSIONS: This study confirms our ability to consistently and accurately identify the normal pituitary gland in patients with macroadenomas with the golden-angle radial sparse parallel technique with quantitative permeability measurements and enhancement-time curves.

OBJECTIVE: The purpose of this study is to evaluate the roles of self-directed learning and continual feedback in the learning curve for tumor detection by novice readers of prostate MRI. MATERIALS AND METHODS: A total of 124 prostate MRI examinations classified as positive (n = 52; single Prostate Imaging Reporting and Data System [PI-RADS] category 3 or higher lesion showing Gleason score >/= 7 tumor at MRI-targeted biopsy) or negative (n = 72; PI-RADS category 2 or lower and negative biopsy) for detectable tumor were included. These were divided into four equal-sized batches, each with matching numbers of positive and negative examinations. Six second-year radiology residents reviewed examinations to localize tumors. Three of the six readers received feedback after each examination showing the preceding case's solution. The learning curve, plotting accuracy over time, was assessed by the Akaike information criterion (AIC). Logistic regression and mixed-model ANOVA were performed. RESULTS: For readers with and without feedback, the learning curve exhibited an initial rapid improvement that slowed after 40 examinations (change in AIC > 0.2%). Accuracy improved from 58.1% (batch 1) to 71.0-75.3% (batches 2-4) without feedback and from 58.1% to 72.0-77.4% with feedback (p = 0.027-0.046), without a difference in the extent of improvement (p = 0.800). Specificity improved from 53.7% to 68.5-81.5% without feedback and from 55.6% to 74.1-81.5% with feedback (p = 0.006-0.010), without a difference in the extent of improvement (p = 0.891). Sensitivity improved from 59.0-61.5% (batches 1-2) to 71.8-76.9% (batches 3-4) with feedback (p = 0.052), though did not improve without feedback (p = 0.602). Sensitivity for transition zone tumors exhibited larger changes (p = 0.024) with feedback than without feedback. Sensitivity for peripheral zone tumors did not improve in either group (p > 0.3). Reader confidence increased only with feedback (p < 0.001). CONCLUSION: The learning curve in prostate tumor detection largely reflected self-directed learning. Continual feedback had a lesser effect. Clinical prostate MRI interpretation by novice radiologists warrants caution.

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.

RATIONALE AND OBJECTIVE: The purpose of this study was to evaluate themes related to patients' experience in undergoing mammography, as expressed on Twitter. METHODS: A total of 464 tweets from July to December 2015 containing the hashtag #mammogram and relating to a patient's experience in undergoing mammography were reviewed. RESULTS: Of the tweets, 45.5% occurred before the mammogram compared to 49.6% that occurred afterward (remainder of tweets indeterminate). However, in patients undergoing their first mammogram, 32.8% occurred before the examination, whereas in those undergoing follow-up mammogram, 53.0% occurred before the examination. Identified themes included breast compression (24.4%), advising other patients to undergo screening (23.9%), recognition of the health importance of the examination (18.8%), the act of waiting (10.1%), relief regarding results (9.7%), reflection that the examination was not that bad (9.1%), generalized apprehension regarding the examination (8.2%), interactions with staff (8.0%), the gown (5.0%), examination costs or access (3.4%), offering or reaching out for online support from other patients (3.2%), perception of screening as a sign of aging (2.4%), and the waiting room or waiting room amenities (1.3%). Of the tweets, 31.9% contained humor, of which 56.1% related to compression. Themes that were more common in patients undergoing their first, rather than follow-up, mammogram included breast compression (16.4% vs 9.1%, respectively) and that the test was not that bad (26.2% vs 7.6%, respectively). CONCLUSION: Online social media provides a platform for women to share their experiences and reactions in undergoing mammography, including humor, positive reflections, and encouragement of others to undergo the examination. Social media thus warrants further evaluation as a potential tool to help foster greater adherence to screening guidelines.

OBJECTIVE: The objective of this study was to identify geographic and temporal patterns related to the frequencies of online searches within the United States for information on imaging-based cancer screening tests. MATERIALS AND METHODS: Google Trends, a web-based tool for identifying the frequency of online searches, was used to determine, on both a monthly and a geographic basis, the relative frequency of searches for imaging-based cancer screening tests in the United States from 2004 through 2014. Findings were evaluated qualitatively. RESULTS: Searches for "mammography" decreased slightly overall, although they peaked in October (Breast Cancer Awareness Month) in most years and spiked in November 2009 (when the updated U.S. Preventive Services Task Force screening mammography guidelines were released). The frequency of searches for "tomosynthesis" increased rapidly from 2009 through 2014. On the other hand, the frequency of searches for "lung cancer screening" decreased slightly from 2006 through 2010, increased rapidly from 2011 through 2014, and exhibited a spike in November 2010 (when the results of the National Lung Screening Trial were released). Searches for "virtual colonoscopy" decreased substantially from 2004 through 2010, remained stable from 2011 through 2014, and spiked in months coinciding with the publication of the results of large relevant clinical trials and a press release announcing that the president of the United States was undergoing virtual colonoscopy. The frequency of searches for "prostate MRI" was stable from 2006 through 2010 and increased rapidly from 2011 through 2014. Searches for "prostate MRI biopsy" increased rapidly in 2013 and 2014. These searches occurred predominantly in densely populated areas (e.g., searches for "lung cancer screening," "prostate MRI," and "tomosynthesis" were highest in New York City). CONCLUSION: Online search patterns indicate geographic and short- and long-term temporal variation in the interest in cancer screening examinations among the U.S. POPULATION: These trends may indicate pending shifts in the use of these examinations.