Colin Strickland

Measurement of lateral acetabular coverage: a comparison between CT and plain radiography

We prospectively evaluated the degree of absolute agreement between measurements of lateral center-edge angle (LCEA) on plain radiography (XR) and computed tomography (CT) in a consecutive cohort of 205 patients (410 hips) undergoing hip arthroscopy. Preoperative measurements of the LCEA were performed bilaterally utilizing standardized anteroposterior radiographs and coronal reformatted CT scans. Demographic variables including age, gender, height, weight, BMI and clinical diagnosis were recorded for all patients. Overall, measured values of the LCEA were 2.1° larger on CT compared with XR (32.9° versus 30.8°, P < 0.001). Subgroup analysis revealed the highest mean difference in hips with acetabular dysplasia and concomitant cam-type femoroacetabular impingement (FAI) [mean difference (CT–XR) 5.5°, 95% confidence interval (CI) 3.7°–7.3°, P = 0.011], followed by hips with isolated acetabular dysplasia (mean difference [CT–XR] 4.9°, 95% CI 2.7°–7.0°, P < 0.001). In contrast, 119 (29.0%) of the hips demonstrated larger measurements of the LCEA on 25 XR relative to CT. Of these hips, 20 (16.8%) had pincer-FAI and 25 had cam-FAI (21.0%), representing a significantly higher proportion compared with all other clinical subgroups (P = 0.045 and 0.036, respectively). Our study demonstrates measured values of the LCEA are consistently inflated on CT relative to XR for a wide variety of hip pathologies, highlighting the need for standardization and validation of CT-based measurements to improve the quality of clinical decision making. Level of Evidence: Diagnostic Level II.

Morphologic Imaging of Articular Cartilage

Magnetic resonance (MR) imaging plays an integral role in the assessment of articular cartilage. This article discusses the role of MR imaging in the evaluation of articular cartilage, the appearance of cartilage lesions on MR imaging, and the currently available MR imaging techniques for evaluating cartilage morphology. A limitation of currently available sequences is their inability to consistently detect superficial degenerative and posttraumatic cartilage lesions that may progress to more advanced osteoarthritis. In the future, improved image quality may allow for better evaluation of articular cartilage and earlier detection of cartilage lesions.

Introduction of a Virtual Workstation Into Radiology Medical Student Education

OBJECTIVE. This article describes the creation of a virtual workstation for use by medical students and implementation of that workstation in the reading room. CONCLUSION. A radiology virtual workstation for medical students was created using OsiriX imaging software to authentically simulate the experience of interacting with cases selected to cover important musculoskeletal imaging diagnoses. A workstation that allows the manipulation and interpretation of complete anonymized DICOM images may enhance the educational experience of medical students.

VIDEO: Ultrasound-Guided Intervention at the Posterior Hip

OBJECTIVE The purpose of this video article is to demonstrate sonographic anatomy at the posterior hip and to describe a number of diagnostic and therapeutic interventions that may be performed at this location with sonographic guidance. Injection techniques at the piriformis muscle, ischial bursa, hamstring origin, and ischiofemoral space are described and demonstrated. CONCLUSION Ultrasound is well adapted to the evaluation and treatment of conditions encountered at the posterior hip. Sonographic guidance is a useful tool that allows a trained operator to safely and effectively perform a range of injections.

Lung abnormalities in subjects with elevations of rheumatoid arthritis-related autoantibodies without arthritis by examination and imaging suggest the lung is an early and perhaps initiating site of inflammation in rheumatoid arthritis

Background/objectives Elevations of serum autoantibodies (Abs) prior to joint symptoms suggest that rheumatoid arthritis (RA) may be initiated outside of the joints. This site is unknown, although several factors suggest that it may be the lungs including the association of inhaled factors such as smoking with RA. Our purpose herein was to evaluate a hypothesis that the lung is a site of initiation of RA-related autoimmunity by comparing lung findings in RA-related Ab+ subjects at risk for future RA but without current inflammatory arthritis (IA) to Ab- controls and patients with established early RA. Materials/methods 45 Ab+ cases without IA on 68 joint exam were identified from the Studies of the aetiology of RA project, a prospective study of preclinical RA. These cases were positive for Abs >96% specific for future RA: anti cyclic citrullinated peptides (CCP2) (Axis-Shield) or CCP3.1 (INOVA, San Diego, CA, USA), and/or ≥2 rheumatoid factor (RF) isotypes (IgA, M, G) (INOVA) (N=9 CCP2+; N=25 CCP3.1+; N=11 RFs+ only). Additionally, 16 Ab-sera controls (frequency matched to Ab+ cases on age, sex and smoking) and 12 patients with early RF/aCCP2+ RA (<1 year) were selected. All subjects underwent high-resolution CT (HRCT) of the lungs, interpreted in a blinded fashion by two chest radiologists according to established criteria (Fleischner Society; Hansell, et al 2008). To evaluate for synovitis not detected on joint exam, a subset of Ab+ cases underwent contrasted MRI of the metacarpophalangeals, wrists and metatarsophalangeals, scored for synovitis by two joint radiologists using the outcome measures in rheumatoid arthritis clinical trials/rheumatoid arthritis MRI scoring system protocols. Results 45 Ab+ cases were a mean age of 54, 56% female and 33% smokers (no significant differences from Ab-controls). 77% of Ab+ cases had airways disease on HRCT including bronchial wall thickening, bronchiectasis, centrilobular opacities and air trapping, compared to 31% of Ab-controls (p<0.01). Of the 30 Ab+ cases that were never smokers, 70% had airways disease compared to 3/12 (25%) of never smoking controls (p=0.01). No Ab+ case had evidence of IA on joint exam at time of lung evaluation, and additionally, 15 Ab+ cases with abnormal lungs that underwent joint MRI had no synovitis by imaging. One Ab+ subject with airways disease developed RA by 1987 criteria (Arnett, et al 1988) ∼13 mos. after lung study. Finally, 9/12 (75%) of early RA subjects (mean age 50, 58% female, 42% smokers) studied in parallel had radiographically indistinguishable airways abnormalities when compared to the Ab+ cases (p>0.5). Conclusions Airways abnormalities are present in a high proportion of RA-specific Ab+ cases without IA (examination or MRI), and these lung abnormalities are similar to those in patients diagnosed with early RA. This suggests that there is a continuum of lung injury during the development of RA, and that lungs are either a site of RA-related autoimmune-mediated injury during the presymptomatic phase of disease, or more likely a site of initiation of RA-related autoimmunity perhaps due to external factors beyond smoking that generate local inflammation, especially since the airways interact substantially with the environment. Prospective studies are ongoing to evaluate the generation of RA-specific in the lungs, and to follow the evolution of autoimmunity and IA in these subjects.

Arthrographic Anatomy of the Biceps Tendon Sheath: Potential Implications for Selective Injection

The purpose of this investigation was to better define the anatomical features of the biceps tendon sheath, including the distance the sheath extends below the inferior margin of the subscapularis tendon and below the termination of the bony bicipital groove. A total of 110 magnetic resonance and computed tomography arthrograms performed during 1-year period at our institution were retrospectively reviewed, and the length of the biceps tendon sheath and distances from the inferior margin of the subscapularis tendon and from the termination of the bicipital groove to the inferior margin of the biceps tendon sheath were measured by 3 radiologists. The mean length of the biceps tendon sheath was 47.5mm. The mean distances from the inferior margin of the subscapularis tendon and from the inferior margin of the bicipital groove to the distal extent of the biceps tendon sheath were 24.5mm and 11.9mm, respectively. The relationships among these 3 anatomical measurements and biological confounders of sex and age were investigated while controlling for measurement variability. The anatomical relationships between the biceps tendon sheath and surrounding structures may have implications for needle placement when attempting to inject into the biceps tendon sheath for diagnostic or therapeutic purposes.

Technical Innovation: The Automated Residency Match Rank List

The creation of the final rank list for the National Residency Matching Program every year is a laborious task requiring the time and input of numerous faculty members and residents. This article describes the creation of an automated visual rank list to efficiently organize and guide discussion at the yearly rank meeting so that the task may be efficiently and fairly completed. The rank list was created using a PowerPoint (Microsoft) macro that can pull information directly from a spreadsheet to generate a visual rank list that can be modified on-the-fly during the final rank list meeting. An automatically created visual rank list helps facilitate an efficient meeting and creates an open and transparent process leading to the final ranking.

Postoperative Imaging of the Ankle

OBJECTIVE The purpose of this article is to review imaging after commonly encountered surgical interventions of the ligaments, tendons, and soft tissues around the ankle. Intraoperative images, when available, are provided to improve conceptual understanding of these complex procedures. CONCLUSION Surgical interventions in the ankle are becoming more prevalent with increasing athletic demands and emerging focus on techniques for prevention of joint injury. Knowledge of the surgical techniques, imaging appearances, and complications in the postoperative ankle is necessary for the accurate diagnosis of postoperative complications and for optimal patient care.

Magnetic Resonance Imaging Comparison of Repaired versus Non-Repaired Hip Capsule in Patients Undergoing Hip Arthroscopy for Femoroacetabular Impingement: A Double-Blind, Randomized Controlled Trial

Objectives: Techniques used in hip arthroscopy continue to evolve and controversy surrounds the need for capsule repair following surgical intervention. The purposes of this study were to evaluate the magnetic resonance imaging (MRI) appearance of the hip capsule in patients with femoroacetabular impingement (FAI) undergoing hip arthroscopy with capsular repair versus non-repair. Methods: A multicenter clinical trial was performed with 35 patients (50 hips) undergoing hip arthroscopy for treatment of FAI. Each hip was preoperatively randomized to capsular repair versus non-repair. MRI evaluation was performed by a radiologist at 6 and 24 weeks postoperatively. Patients and the radiologist were blinded to the randomization. Capsular defect size and the thickness of the capsule at the capsulotomy site and at locations both proximal and distal to the defect were recorded on each scan to determine their change over time. Results: Compared to patients without capsular repair, those with capsular repair demonstrated significantly decreased mean capsular gapping at articular and muscular portions of the hip capsule at 6 weeks postoperatively (p < 0.001). This difference normalized between the two cohorts by 24 weeks postoperatively, with a significantly decreased mean capsular gapping at articular and muscular attachment sites of the hip capsule compared to 6 weeks postoperatively (p < 0.03). Defects were readily apparent on MRI imaging in regions where the capsule was not repaired. In contrast, irregular capsular thickening without a discrete defect was visible in most cases where the capsule was repaired at the time of arthroscopy. The appearance was variable after 24 weeks. The capsular defects that did close universally showed closure of the defect beginning at the muscular side of the capsule with bridging of capsular tissue then filling in on the articular side. Conclusion: Arthroscopic hip capsule repair results in significantly less capsule gapping at 6-week follow-up compared with non-repair, though the difference in gap size normalizes by 24-week follow-up.

Does the Oral “Mock Board” Examination Still Have a Role as a Training Tool?

RATIONALE AND OBJECTIVES The American Board of Radiology has adopted a new standardized board examination and the traditional oral examination has been abandoned. Although many programs have changed their educational efforts to reflect the new test format, some faculty members and residents have expressed a desire to keep an oral examination as a component of education and evaluation in radiology residency programs. MATERIALS AND METHODS An oral comprehensive examination including all the appropriate subspecialties was administered to each second year and third year resident in our training program by faculty members. Both the resident examinees and faculty examiners were surveyed after the examination to gauge the perceived value of the experience. RESULTS Residents were divided in their perceptions of the fairness and utility of an oral examination as a tool to aid in board preparation and as an assessment of their knowledge and communication skill. Faculty members were universal in their endorsement of the oral examination and suggested continued use of the technique. CONCLUSIONS Residents and faculty members have differing perceptions of an oral examination delivered during training to assess knowledge and communication skill. The value of an oral examination in providing actionable feedback to trainees and the possibility of detecting struggling residents made it useful in our training program, and it thus it has been implemented for future years. Whether resident performance measured by this technique is predictive of success on American Board of Radiology examinations remains unclear.