Abstract
Recently MR imaging of the shoulder has come to our notice as being noninvasive and accurate. With the purpose of evaluating its diagnostic values detecting the pathology of an unstable shoulder MRI was performed on recurrent anterior dislocations of the shoulder, which were compared with their CT arthrographs and the MRIs of stable shoulders.
Sixteen patients with recurrent anterior dis location of the shoulder (average age 24.6) were assessed using Ti weighted axial images obtained from a Diasonics 0.064 Tesla permanent magnet system. Twelve of these patients were concomitantly examined by CT arthrography (CTA). In addition, the MR images of 10 shoulders without instability (average age 23.5) were chosen to serve as the control.
The control images did not show any significant abnormalities, although a mild rounding of the glenoid labrum was seen in 3 shoulders. By contrast,8 disapearances,6 decreases in size and roundings, and 2 roundings were found in the unstable shoulders. But the two roundings of the labrum in the unstable shoulders seemed to be the same as a shoulder without instability.
The CTA findings of the labrum were almost the same as the MR images. Furthermore, CT arthography disclosed a detachment of the anterior capsule which was not detected by the MRI.
Conclusion: Although almost MRI was a useful method for a recurrent anterior dislocation of the shoulder, CT arthrography was superior to MRI in detecting changes of the anterior capsular mechanism.
