MR arthrography of the shoulder: Rethinking traditional imaging procedures to meet the technical requirements of MR imaging guidance

OBJECTIVE. The purpose of this study was to determine the feasibility of and the appropriate technique for performance of MR imaging-guided arthrography of the shoulder. SUBJECTS AND METHODS. Thirty-eight MR imaging-guided glenohumeral joint punctures were performed using an open C-arm scanner with a vertically oriented magnetic field, adapted for interventional procedures. Two different approaches to the shoulder were used: a modification of the traditional anterior approach (seven procedures), and an anterosuperior approach (31 procedures) mimicking the anterior arthroscopy portal. The average procedure duration was determined. A retrospective review of needle mediolateral and anterioposterior position was determined for the anterosuperior approaches. RESULTS. Average procedure duration was 21 min for the anterior approach and 12 min for the anterosuperior approach. Subjectively, needle conspicuity was minimal with the anterior approach, contributing to prolonged imaging times. Needle visualization was much improved with the anterosuperior approach. Nine of the 31 anterosuperior procedures involved inadvertent injection of the subacromial or subdeltoid bursa. At the time of retrospective review, the needle was too laterally or too anteriorly positioned in six of these nine patients. CONCLUSION. With consideration of the technical demands of MR imaging guidance for interventional procedures, MR imaging-guided arthrography of the shoulder is feasible. The traditional radiologic approach to the shoulder must be modified to provide adequate visualization of the needle. The anterosuperior approach meets this need.