Although magnetic resonance imaging is very sensitive and even though pathology in the rotator cuff is readily detected, it is often difficult to distinguish between complete rotator cuff tears, partial rotator cuff tears, and area of tendinitis. This article reports the results of a new technique for evaluation of shoulder pathology, which the authors have labeled magnetic resonance arthrography, and compares the results of magnetic resonance arthrography with those of conventional magnetic resonance imaging.