MR arthrography of the rotator cuff and labral-ligamentous complex.

In MR imaging of the shoulder, diagnostic success requires the delineation of complex anatomic structures and the demonstration of subtle abnormalities. Magnetic resonance (MR) arthrography extends the capabilities of conventional MR imaging because contrast solution separates intra-articular structures and outlines abnormalities. There are several major contributions of MR arthrography. In assessment of the rotator cuff, arthrographic MR images enable the accurate differentiation of full-thickness tears from other cuff abnormalities, as well as the determination of tendon quality. In shoulders with suspected glenohumeral instability, arthrographic MR images show the locations of labral tears relative to the origins of glenohumeral ligaments. This article illustrates normal arthrographic MR features of the shoulder as well as common pathological disorders of the rotator cuff and labral-ligamentous complex.