[Magnetic resonance tomography of the shoulder. Possibilities of over interpretation of normal findings].

In order to test the criteria for abnormalities of the shoulder as seen on MR, 30 normal shoulders were examined. The examination included T1, proton and T2-weighted SE sequences and T2*-weighted FE sequences, using transverse, oblique coronary and oblique sagittal planes. In 57% there was increased signal intensity in the tendon of the rotator cuff; this might have been interpreted as a rupture of the cuff or tendinitis. Anatomical examination suggests that the finding is due to a normal layer between the long head of the biceps and the tendon joint complex. The anterior glenoid labrum could not be clearly delineated in 57% and the posterior labrum in 5%. In two cases there was a superior, postero-lateral defect in the head of the humerus. The currently accepted criteria for the MRT diagnosis of shoulder abnormalities need to be critically re-evaluated.