Faculty Bibliography

PURPOSE: To compare diagnostic performance of a 5-min knee MRI protocol to that of a standard knee MRI. MATERIALS AND METHODS: One hundred 3 T (100 patients, mean 38.8 years) and 50 1.5 T (46 patients, mean 46.4 years) MRIs, consisting of 5 fast, 2D multi-planar fast-spin-echo (FSE) sequences and five standard multiplanar FSE sequences, from two academic centers (1/2015-1/2016), were retrospectively reviewed by four musculoskeletal radiologists. Agreement between fast and standard (interprotocol agreement) and between standard (intraprotocol agreement) readings for meniscal, ligamentous, chondral, and bone pathology was compared for interchangeability. Frequency of major findings, sensitivity, and specificity was also tested for each protocol. RESULTS: Interprotocol agreement using fast MRI was similar to intraprotocol agreement with standard MRI (83.0-99.5%), with no excess disagreement (/= 0.215), except more ACL tears on fast MRI (p = 0.021) and more cartilage defects on standard MRI (p < 0.001). Sensitivities (59-100%) and specificities (73-99%) of fast and standard MRI were not significantly different for meniscal and ligament tears (95% CI for difference, -0.08-0.08). For cartilage defects, fast MRI was slightly less sensitive (95% CI for difference, -0.125 to -0.01) but slightly more specific (95% CI for difference, 0.01-0.5) than standard MRI. CONCLUSION: A fast 5-min MRI protocol is interchangeable with and has similar accuracy to a standard knee MRI for evaluating internal derangement of the knee.

RATIONALE AND OBJECTIVES: Here we review the current state of multicenter radiology research (MRR), and utilize a survey of experienced researchers to identify common advantages, barriers, and resources to guide future investigators. MATERIALS AND METHODS: The Association of University Radiologists established a Radiology Research Alliance task force, Multi-center Research Studies in Radiology, composed of 12 society members to review MRR. A REDCap survey was designed to gain more insight from experienced researchers. Recipients were authors identified from a PubMed database search, utilizing search terms "multicenter" or "multisite" and "radiology." The survey included investigator background information, reasons why, barriers to, and resources that investigators found helpful in conducting or participating in MRR. RESULTS: The survey was completed by 23 of 80 recipients (29%), the majority (76%) of whom served as a primary investigator on at least one MRR project. Respondents reported meeting collaborators at national or international (74%) and society (39%) meetings. The most common perceived advantages of MRR were increased sample size (100%) and improved generalizability (91%). External funding was considered the most significant barrier to MRR, reported by 26% of respondents. Institutional funding, setting up a central picture archiving and communication system, and setting up a central database were considered a significant barrier by 30%, 22%, and 22% of respondents, respectively. Resources for overcoming barriers included motivated staff (74%), strong leadership (70%), regular conference calls (57%), and at least one face-to-face meeting (57%). CONCLUSIONS: Barriers to MRR include funding and establishing a central database and a picture archiving and communication system. Upon embarking on an MRR project, forming a motivated team who meets and speaks regularly is essential.

BACKGROUND: The purpose of this study was to determine the value of magnetic resonance imaging (MRI) and ultrasound-based imaging strategies in the evaluation of a hypothetical population with a symptomatic full-thickness supraspinatus tendon (FTST) tear using formal cost-effectiveness analysis. METHODS: A decision analytic model from the health care system perspective for 60-year-old patients with symptoms secondary to a suspected FTST tear was used to evaluate the incremental cost-effectiveness of 3 imaging strategies during a 2-year time horizon: MRI, ultrasound, and ultrasound followed by MRI. Comprehensive literature search and expert opinion provided data on cost, probability, and quality of life estimates. The primary effectiveness outcome was quality-adjusted life-years (QALYs) through 2 years, with a willingness-to-pay threshold set to $100,000/QALY gained (2016 U.S. dollars). Costs and health benefits were discounted at 3%. RESULTS: Ultrasound was the least costly strategy ($1385). MRI was the most effective (1.332 QALYs). Ultrasound was the most cost-effective strategy but was not dominant. The incremental cost-effectiveness ratio for MRI was $22,756/QALY gained, below the willingness-to-pay threshold. Two-way sensitivity analysis demonstrated that MRI was favored over the other imaging strategies over a wide range of reasonable costs. In probabilistic sensitivity analysis, MRI was the preferred imaging strategy in 78% of the simulations. CONCLUSION: MRI and ultrasound represent cost-effective imaging options for evaluation of the patient thought to have a symptomatic FTST tear. The results indicate that MRI is the preferred strategy based on cost-effectiveness criteria, although the decision between MRI and ultrasound for an imaging center is likely to be dependent on additional factors, such as available resources and workflow.

OBJECTIVE: This article reviews the normal anatomy of the extensor tendons of the wrist as well as the clinical presentation and MRI appearances of common tendon abnormalities, such as tears, tenosynovitis, intersection syndromes, and associated or predisposing osseous findings. Treatment options are also discussed. CONCLUSION: We review the anatomy and normal MRI appearance of the clinically important dorsal extensor tendons of the wrist, in addition to the spectrum of abnormalities associated with these tendons.

OBJECTIVE: We are fortunate to live in a time when real advances in medicine are happening at an increasingly rapid pace. This is especially true in the field of radiology, and keeping abreast of these advances is one of the main challenges of clinical practice. Traditionally, cutting edge techniques in our field have been researched and validated at major academic medical centers before slowly making their way into the armamentarium of routine clinical practice. However, the improved ability to communicate and disseminate information in our modern age has facilitated more rapid implementation of new techniques to allow us to better serve our patients. CONCLUSION: As such, this article aims to review the current standards for MRI of the shoulder used in routine practice. Furthermore, we will discuss some of the most recent advances in shoulder MRI, with particular emphasis on the applicability of an additional axial 3D T1-weighted FLASH sequence with Dixon-based water-fat separation in routine clinical practice that can be useful in characterizing several commonly encountered pathologic processes of the shoulder joint.

OBJECTIVE: The objective of our study was to assess temporal changes in the utilization of musculoskeletal extremity imaging in Medicare beneficiaries over a recent 20-year period (1994-2013). MATERIALS AND METHODS: Medicare Physician Supplier Procedure Summary Master Files from 1994 through 2013 were used to study changing utilization and utilization rates of the four most common musculoskeletal imaging modalities: radiography, MRI, CT, and ultrasound. RESULTS: Utilization rates (per 1000 beneficiaries) for all four musculoskeletal extremity imaging modalities increased over time: 43% (from 441.7 to 633.6) for radiography, 615% (5.4-38.6) for MRI, 758% (1.2-10.3) for CT, and 500% (1.8-10.8) for ultrasound. Radiologists were the most common billing specialty group for all modalities throughout the 20-year period, maintaining dominant market shares for MRI and CT (84% and 96% in 2013). In recent years, the second most common billing group was orthopedic surgery for radiography, MRI, and CT and podiatry for ultrasound. The physician office was the most common site of service for radiography, MRI, and ultrasound, whereas the hospital outpatient and inpatient settings were the most common sites for CT. CONCLUSION: In the Medicare population, the most common musculoskeletal extremity imaging modalities increased substantially in utilization over the 2-decade period from 1994 through 2013. Throughout that time, radiology remained the most common billing specialty, and the physician office and hospital outpatient settings remained the most common sites of service. These insights may have implications for radiology practice leaders in making decisions regarding capital infrastructure, workforce, and training investments to ensure the provision of optimal imaging services for extremity musculoskeletal care.

Tophaceous gout is painful and impairs quality of life. The optimal modality for assessing tophus resolution in response to urate-lowering treatment remains poorly defined. Using pegloticase as a model system for resolving tophi, we compared multiple imaging and physical diagnostic strategies for assessing tophus resolution. A 32-year-old subject with chronic refractory tophaceous gout was enrolled and received 6 months of pegloticase treatment. Measurements of tophi using vernier calipers (monthly), photographs and musculoskeletal ultrasound (MSK-US; every 3 months), and dual-energy CT (DECT) were compared. Pegloticase persistently lowered the patient's sUA to <0.5 mg/dl. After 6 months, caliper measurements revealed 73, 60, and 61% reductions of three index tophi, while MSK-US revealed 47, 65, and 48% reductions. In contrast, DECT revealed 100% resolution of monosodium urate deposition in all three index tophi, and resolution or improvement of all other tophi identified. On caliper and MSK-US measurement, index tophus size fluctuated, with some lesions enlarging before ultimately contracting. Correlation between assessment modalities during tophus resolution may be poor. DECT identifies urate deposits invisible to physical exam and reveals that some urate deposits completely resolve even as their physically/sonographically measurable lesions persist. Recognition of urate resorption during the urate-lowering process may be confounded by fluctuating lesion volumes during initial tophus breakdown. While DECT was superior for identifying total (including occult) urate deposition, and assessing volume of deposits, other modalities may permit better assessment of non-urate tophus components.

Purpose To evaluate the diagnostic accuracies of nonenhanced magnetic resonance (MR) imaging and MR arthrography for diagnosis of superior labrum anterior-to-posterior (SLAP) tears by using a systematic review and meta-analysis. Materials and Methods A comprehensive literature search was performed on the two main concepts of MR imaging (MR imaging, and direct and indirect MR arthrography) and SLAP tears. Inclusion criteria consisted of original studies that assessed the diagnostic accuracy of MR imaging, direct MR arthrography, and/or indirect MR arthrography for the detection of SLAP tears, by using surgical findings as the reference standard. The Quality Assessment of Diagnostic Accuracy Studies 2, or QUADAS-2 Quality Assessment of Diagnostic Accuracy Studies 2 Quality Assessment of Diagnostic Accuracy Studies 2 , tool was used to assess methodologic quality. Meta-analyses were performed that compared MR imaging studies to direct MR arthrography studies and indirect MR arthrography studies, 3-T studies to 1.5-T studies, and low-bias MR imaging studies to low-bias direct MR arthrography studies. Study variation was analyzed by using the Cochran Q test of heterogeneity and the I2 statistic. Results Thirty-two studies met inclusion and exclusion criteria, including 3524 imaging examinations: 1963 direct MR arthrography examinations (23 studies), 1402 MR examinations (14 studies), and 159 indirect MR arthrography examinations (three studies). Twelve studies had low risk for bias, two had questionable risk, and 18 had high risk. Mean sensitivities of direct MR arthrography, MR imaging, and indirect MR arthrography for SLAP tear diagnosis were 80.4%, 63.0%, and 74.2%, respectively. Mean specificities of direct MR arthrography, MR imaging, and indirect MR arthrography were 90.7%, 87.2%, and 66.5%, respectively. Summary receiver operator characteristic (ROC) curve demonstrated superior accuracy of direct MR arthrography compared with those of MR imaging and indirect MR arthrography. Similar findings were observed in the low-bias subanalysis. Summary ROC curve demonstrated overall superiority of 3-T imaging, with or without intra-articular contrast material compared with 1.5-T imaging, with or without intra-articular contrast material. Significant variance was observed for MR imaging and direct MR arthrography (P < .001) studies for both mean sensitivity and specificity. Conclusion Direct MR arthrography appears to be more accurate than nonenhanced MR imaging for diagnosis of SLAP tears, whereas 3-T MR imaging with or without intra-articular contrast material appears to improve diagnostic accuracy compared with 1.5-T MR imaging with or without intra-articular contrast material. (c) RSNA, 2017 Online supplemental material is available for this article.

Chronic hip pain is a common clinical problem whose cause is often elucidated by imaging. The ACR Appropriateness Criteria for chronic hip pain define best practices of image ordering. Clinical scenarios are followed by the imaging choices and their appropriateness. The information is in ordered tables with an accompanying narrative explanation to guide physicians to order the right test. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.