Comparison of conventional and computed arthrotomography with MR imaging in the evaluation of the shoulder.

To compare conventional arthrography and computed arthrotomography (CAT) with magnetic resonance (MR) imaging in the evaluation of the shoulder, we studied 18 patients who underwent conventional double contrast arthrography and CAT, and T1-, balanced, and T2-weighted MR imaging. The arthrograms were independently reviewed by two of the authors and the MR images were independently reviewed by three other authors in a systematic fashion with the aid of a prewritten evaluation form. The findings were compared among reviewers and between imaging methods. We found MR comparable to conventional arthrography in the evaluation of the rotator cuff; however, MR also enabled evaluation of tendonitis, which could not be accomplished with conventional arthrography. Because of MR's superior soft tissue imaging capability, we were able to stage the impingement syndrome. Magnetic resonance also allowed evaluation of the glenoid labrum and capsuloligamentous structures and assessment of instability in a fashion similar to CAT. In most cases, information obtained from MR equaled or exceeded that obtained from conventional arthrography and CAT. With refinement in technique and increased experience, we believe that MR may replace arthrography in the evaluation of the shoulder.