Faculty Bibliography

OBJECTIVE. The purpose of this article is to perform an intraindividual comparison between 1.5 T and 3 T chemical-shift MRI in differentiating adrenal adenomas and nonadenomas, including comparison of quantitative thresholds. MATERIALS AND METHODS. In this retrospective study, 37 adrenal lesions in 36 patients (20 men and 16 women; mean [+/- SD] age, 66.7 +/- 12.9 years; 27 benign adenomas in 27 patients; 10 nonadenomas in nine patients) imaged at 1.5 T and 3 T were identified. Two readers qualitatively assessed intralesional signal loss between in- and opposed-phase images. One reader placed ROIs on adrenal lesions, spleen, liver, and muscle. Quantitative measures of signal loss, such as signal intensity (SI) index, adrenal-to-spleen ratio, adrenal-to-liver ratio, and adrenal-to-muscle ratio, were calculated. Qualitative and quantitative measures between field strengths were assessed with McNemar test and ROC analysis, respectively. RESULTS. Accuracy in qualitative adenoma identification (86.5% [32/37] at 1.5 T and 81.1% [30/37] at 3 T for reader 1; 81.1% [30/37] at 1.5 T and 83.8% [31/37] at 3 T for reader 2; both p >/= 0.180) was equivalent at both field strengths. AUCs were not statistically significantly different between field strengths for quantitative measures: AUCs at 1.5 T versus 3 T were 0.956 versus 0.915 for SI index, 0.963 versus 0.870 for adrenal-to-spleen ratio, 0.935 versus 0.852 for adrenal-to-liver ratio, and 0.948 versus 0.948 for adrenal-to-muscle ratio (all p > 0.11). The optimal threshold for SI index was lower at 3 T (> 7.4%) than at 1.5 T (> 21.6%) but had similar sensitivity (1.5 T, 92.6% [25/27]; 3 T, 88.9% [24/27]) and specificity (1.5 T, 90.0% [9/10]; 3 T, 90.0% [9/10]). CONCLUSION. Chemical-shift imaging has similar diagnostic efficacy for differentiating adrenal adenomas and nonadenomas at 1.5 T and 3 T. However, quantitative measures have different thresholds for this differentiation at 3 T; in particular, the commonly applied SI index is much lower at 3 T.

OBJECTIVE. The purpose of this study was to retrospectively evaluate the impact of multiparametric prostate MRI, including diffusion-weighted imaging (DWI) performed using different b values as well as dynamic contrast-enhanced MRI (DCE-MRI) on the accuracy, sensitivity, and specificity for transition zone (TZ) tumor detection and localization. MATERIALS AND METHODS. We included 106 prostate cancer patients (mean age [+/- SD], 62 +/- 7 years) who underwent 3-T MRI with a pelvic phased-array coil before radical prostatectomy. Three radiologists independently reviewed cases to record the likelihood of tumor in each of six TZ regions. Scores were initially assigned using T2-weighted imaging alone, reassigned after integration of DWI at b = 1000 s/mm(2) and corresponding apparent diffusion coefficient (ADC) maps, reassigned again after integration of DWI at b = 2000 s/mm(2), and reassigned a final time after integration of DCE-MRI. Generalized estimating equations based on binary logistic regression were used to compare sessions for TZ tumor detection, using prostatectomy findings as reference standard. RESULTS. Of the TZ sextants, 9.7% (62/636) contained tumor. All readers had higher sensitivity for T2-weighted imaging integrated with DWI at b = 1000 s/mm(2) and ADC compared with T2-weighted imaging alone (reader 1, 54.8% vs 33.9%; reader 2, 53.2% vs 22.6%; and reader 3, 50.0% vs 19.4% [p /= 0.054). Other measures were similar across the four sessions (reader 1, specificity 97.4-98.3% and accuracy 91.2-95.9%; reader 2, specificity 95.8-98.4% and accuracy 91.0-92.6%; reader 3, specificity 90.9-96.7% and accuracy 88.1-89.2%). CONCLUSION. DWI assists TZ tumor detection through higher sensitivity, particularly when using a very high b value; DCE-MRI lacks further additional benefit.

A departmental tool that provides a digital/administrative solution for communication of important imaging findings was evaluated. The tool allows the radiologist to click a button to mark an examination for ordering physician follow-up with subsequent fax and confirmation. The tool's log was reviewed. Of 466 entries; 99.4% were successfully faxed with phone confirmation. Most common reasons for usage were lung nodule/mass (29.2%) and osseous fracture (12.4%). Subsequent clinical action was documented in 41.0% of entries. Our data show the reliability of the tool in assisting the communication of findings, as well as providing documentation of notification, with minimal workflow disruption.

PURPOSE: Dynamic FDG imaging for prostate cancer characterization is limited by generally small size and low uptake in prostate tumors. Our aim in this pilot study was to explore feasibility of simultaneous PET/MRI to guide localization of prostate lesions for dynamic FDG analysis using a graphical approach. METHODS: Three patients with biopsy-proven prostate cancer underwent simultaneous FDG PET/MRI, incorporating dynamic prostate imaging. Histology and multiparametric MRI findings were used to localize tumors, which in turn guided identification of tumors on FDG images. Regions of interest were manually placed on tumor and benign prostate tissue. Blood activity was extracted from a region of interest placed on the femoral artery on PET images. FDG data were analyzed by graphical analysis using the influx constant Ki (Patlak analysis) when FDG binding seemed irreversible and distribution volume VT (reversible graphical analysis) when FDG binding seemed reversible given the presence of washout. RESULTS: Given inherent coregistration, simultaneous acquisition facilitated use of MRI data to localize small lesions on PET and subsequent graphical analysis in all cases. In 2 cases with irreversible binding, tumor had higher Ki than benign using Patlak analysis (0.023 vs 0.006 and 0.019 vs 0.008 mL/cm per minute). In 1 case appearing reversible, tumor had higher VT than benign using reversible graphical analysis (0.68 vs 0.52 mL/cm). CONCLUSIONS: Simultaneous PET/MRI allows localization of small prostate tumors for dynamic PET analysis. By taking advantage of inclusion of the femoral arteries in the FOV, we applied advanced PET data analysis methods beyond conventional static measures and without blood sampling.

Radiologists are increasingly recognizing their role as direct service providers to patients and seeking to offer an exceptional patient experience as part of high-quality service delivery. Patients' perceptions of service delivery are derived from the chain of numerous individual real-time encounters that occur throughout their visit. These so-called "moments of truth" define the overall experience and form the lasting impression of the given practice in their mind. Providing excellent service can be difficult to achieve in practice given its intangible nature as well as the heterogeneity and unpredictability of the large number of patients, frontline staff, and environmental circumstances that define the patient experience. Thus, broad commitment and team effort among all members of a radiology practice are required. This article explores important areas to be considered by a radiology practice to ensure positive and meaningful patient experiences. Specific ways in which every member within the practice, including schedulers, receptionists, technologists, nurses, and radiologists, can contribute to achieving high-quality patient service are discussed. Examples of patient-oriented language that may be useful in particular scenarios in radiology practice are given. The role of the practice's physical facility, including all aspects of its aesthetics and amenities, as well as of Internet services, in shaping the patient experience is also described. Throughout this work, a proactive approach to promoting a service-oriented organizational culture is provided. By improving the patient experience, these strategies may serve to enhance patients' perceptions of radiology and radiologists.

OBJECTIVE. The purpose of this study was to assess perspectives and information relating to CT radiation risk on Twitter, a popular microblogging social network. MATERIALS AND METHODS. Publicly available posts on Twitter ("tweets") containing both the words "CT" and "radiation" were identified from the 1st week of each month in 2013. Type of user posting and source of linked articles were recorded. Two reviewers assessed the content of tweets and links regarding CT's benefit-to-risk ratio (favorable, unfavorable, etc.). RESULTS. Six hundred twenty-one relevant tweets were tweeted by 557 unique users, of whom 90 (16%) were physicians (17 of these were radiologists), 30 (5%) were medical practices or hospitals, 34 (6%) were patients, 8 (1%) were physicists or technologists, and 395 (71%) were other types of users. Two hundred twenty-seven tweets included user commentary regarding CT's benefit-to-risk ratio, of which 134 (59%) were unfavorable or concerned, 65 (29%) were neutral, 22 (10%) were informative regarding CT dose reduction strategies, and only 6 (3%) were favorable. Four hundred seventy-two tweets (76%) included links to a total of 99 unique articles, of which 25 (25%) were unfavorable or concerned, 10 (10%) were favorable, 25 (25%) were neutral, and 39 (39%) were informative regarding CT dose reduction. Article types were non-peer-reviewed medical sources (n = 50), lay press (n = 15), peer-reviewed medical journals (n = 13), blogs (n = 12), advertisements (n = 5), and informational websites (n = 4). CONCLUSION. The large majority of content on Twitter was either unfavorable or concerned regarding CT radiation risk. Most articles were not peer-reviewed and were posted by nonphysicians; posts by physicians were largely by nonradiologists. More active engagement on Twitter by radiologists and physicists and increased dissemination of peer-reviewed articles may achieve a more balanced representation and alleviate concerns regarding CT radiation risk on social networks.

Academic radiology is poised to play an important role in the development and implementation of quantitative imaging (QI) tools. This article, drafted by the Association of University Radiologists Radiology Research Alliance Quantitative Imaging Task Force, reviews current issues in QI biomarker research. We discuss motivations for advancing QI, define key terms, present a framework for QI biomarker research, and outline challenges in QI biomarker development. We conclude by describing where QI research and development is currently taking place and discussing the paramount role of academic radiology in this rapidly evolving field.

Quantitative imaging (QI) is increasingly applied in modern radiology practice, assisting in the clinical assessment of many patients and providing a source of biomarkers for a spectrum of diseases. QI is commonly used to inform patient diagnosis or prognosis, determine the choice of therapy, or monitor therapy response. Because most radiologists will likely implement some QI tools to meet the patient care needs of their referring clinicians, it is important for all radiologists to become familiar with the strengths and limitations of QI. The Association of University Radiologists Radiology Research Alliance Quantitative Imaging Task Force has explored the clinical application of QI and summarizes its work in this review. We provide an overview of the clinical use of QI by discussing QI tools that are currently used in clinical practice, clinical applications of these tools, approaches to reporting of QI, and challenges to implementing QI. It is hoped that these insights will help radiologists recognize the tangible benefits of QI to their patients, their referring clinicians, and their own radiology practice.

RATIONALE AND OBJECTIVES: To retrospectively assess the appropriateness of outpatient abdominal and pelvic computed tomography (CT) and magnetic resonance imaging (MRI) examinations using the American College of Radiology Appropriateness Criteria (AC). MATERIALS AND METHODS: A total of 570 adult outpatient abdominopelvic CT (304) and MRI (266) studies performed in a 1-month period with available documentation of the clinical encounter generating the imaging order were included. On the basis of review of the imaging report and patient record, examinations were classified in terms of match to a specific AC variant, appropriateness score, and the presence of a significant result. Data were analyzed using Fisher's exact test. RESULTS: Forty-five percent of examinations matched an AC variant: 52% of CT and 38% of MRI (P < .001). Ninety-two percent of examinations matching the AC were appropriate: 96% of CT and 86% of MRI (P = .009). Appropriate examinations were more likely to provide a significant result than not appropriate studies (48% vs. 24%, P = .041). Although a significant result was related to the primary study indication more frequently in appropriate than not appropriate examinations, this difference was not significant (93% vs. 80%, respectively, P = .204). The most common indications not matching an AC were colon cancer follow-up (n = 14) and melanoma follow-up (n = 14) among CT, and hepatocellular carcinoma screening (n = 31) and elevated prostate-specific antigen (PSA) without prior biopsy (n = 14) among MRI. CONCLUSIONS: Most examinations matching the AC were appropriate, and appropriate examinations were more likely to have a significant result. However, most examinations, including 62% of MRI, had no relevant clinical condition, highlighting a critical area for future AC expansion and modification.

PURPOSE: To describe the performance of the nation's hospitals in terms of the Hospital Outpatient Quality Reporting Program's imaging efficiency measures. METHODS: Data were obtained from the Hospital Compare website and reflect outpatient Medicare claims of 4,118 hospitals for 5 imaging efficiency metrics: (1) frequency of combination abdominal CT (performed with and without intravenous contrast); (2) combination chest CT (performed with and without intravenous contrast); (3) simultaneous brain/sinus CT; (4) mammography follow-up (diagnostic imaging after screening mammography); and (5) lumbar spine MRI for low back pain without prior conservative therapy. Metrics were summarized and compared with other hospital characteristics. RESULTS: Median frequency was 36.7% for lumbar spine MRI for low back pain and ranged from 1.6% to 7.8% for the remaining measures; however, extreme outliers were observed (maximal frequencies of 79.2%-95.2% for mammography follow-up and combination chest and abdominal CT). Essentially no correlation was found among measures, aside from combination abdominal and chest CT. For some measures, relatively poor performance was more commonly observed among critical access hospitals and physician-owned/proprietary hospitals, and less commonly observed among U.S. News & World Report "best" hospitals and primary residency teaching sites. Frequencies for combination abdominal and chest CT improved from 2013 to 2014 among hospitals with relatively poorer performance. CONCLUSIONS: Although the imaging efficiency measures help identify individual hospitals and hospital categories with relatively inefficient imaging practices, they do not readily identify distinctly positively performing hospitals. Excess utilization was suggested for lumbar spine MRI. Frequency of combination abdominal and chest CT examinations improved over a short time interval.