Adhesive capsulitis is a clinical syndrome of pain and severely decreased joint motion ("frozen shoulder") caused by thickening and contraction of the joint capsule and synovium. Although arthrographic criteria for the diagnosis have been described, to our knowledge, the MR characteristics have not been reported. Accordingly, we studied the MR findings in 10 patients with this syndrome.MR images of 25 subjects were included in the study. Nine had adhesive capsulitis documented by arthrography, and one had adhesive capsulitis proved at surgery. The MR findings in these patients were compared with those of 15 asymptomatic volunteers. Images were assessed for thickness of the joint capsule and synovium, for thickness of the coracohumeral ligament, and for volume of articular fluid. Capsule and synovium thickness was measured adjacent to the axillary recess. The volume of intraarticular fluid was calculated from direct measurements of the axillary recess and biceps tendon sheath. The rotator cuff interval was...