ADHESIVE CAPSULITIS OF THE SHOULDER - MR DIAGNOSIS

OBJECTIVE. Adhesive capsulitis is a clinical syndrome of pain and seve rely decreased joint motion (''frozen shoulder'') caused by thickening and contraction of the joint capsule and synovium, Although arthrogra phic criteria for the diagnosis have been described, to our knowledge, the MR characteristics have not been reported, Accordingly, we studie d the MR findings in 10 patients with this syndrome. MATERIALS AND MET HODS, MR images of 25 subjects were included in the study. Nine had ad hesive capsulitis documented by arthrography, and one had adhesive cap sulitis proved at surgery. The MR findings in these patients were comp ared with those of 15 asymptomatic volunteers. Images were assessed fo r thickness of the joint capsule and synovium, for thickness of the co racohumeral ligament, and for volume of articular fluid. Capsule and s ynovium thickness was measured adjacent to the axillary recess. The Vo lume of intraarticular fluid was calculated from direct measurements o f the axillary recess and biceps tendon sheath. The rotator cuff inter val was qualitatively evaluated for the presence of abnormal tissue, R ESULTS. Thickening of capsule and synovium on mr images was characteri stic of adhesive capsulitis, with a significant difference between mea n thickness in patients with adhesive capsulitis (5.2 mm) and in asymp tomatic volunteers (2.9 mm) (p < .01). Capsule and synovium thickness greater than 4 mm was a specific (95%) and sensitive (70%) criterion f or the diagnosis of adhesive capsulitis, There was no significant diff erence in volume of articular fluid or thickness of the coracohumeral ligament between patients with adhesive capsulitis and asymptomatic vo lunteers (p > .5), The rotator cuff interval was not useful for assess ing changes of adhesive capsulitis, CONCLUSION. Joint capsule and syno vium thickness greater than 4 mm is a useful MR criterion for the diag nosis of adhesive capsulitis, The volume of articular fluid seen on MR images is not significantly diminished in patients with adhesive caps ulitis.