MRI of the shoulder.

Shoulder imaging is one of the major applications in musculoskeletal MRI. In order to analyze the images it is important to keep informed about anatomical and pathological findings and publications. In this article MRI technique, anatomy and pathology is reviewed. Technical considerations about MR sequences and examination strategy are only shortly discussed with emphasis on turbo spin echo and short T1 inversion recovery imaging. Basic anatomy as well as recent findings, including macroscopic aspects of the supraspinatus fat pad, composition of the supraspinatus muscle belly, and variability of the glenohumeral ligaments or coracoid ligament, are presented. Basic pathological conditions are described in detail, e. g. instability particularly problems in differentiating the various subtypes of labral pathology. Rotator cuff diseases are elucidated with emphasis on some rarer entities such as subscapularis calcifying tendinitis, coracoid impingement, chronic bursitis producing the double-line sign, prominent coraco-acromial ligament and the impingement due to an inflamed os acromiale.