[Magnetic resonance imaging of the shoulder: impingement and instability related abnormalities--update 2013].

Magnetic resonance imaging (MRI) plays an important role in the diagnosis and differentiation of numerous shoulder abnormalities and chronic shoulder pain. Important indications for MRI are assessment of the rotator cuff and the labrocapsular complex. The assessment of the rotator cuff muscles is crucial. The value of MR arthrography is discussed. The potential benefit of MR arthrography is the accurate evaluation of subtle rotator cuff abnormalities, shoulder instability-related lesions and the assessment of pathological conditions of the long biceps tendon. The following article describes the most common pathological findings of the shoulder joint and gives a description of the relevant findings for the orthopedic shoulder surgeon. The current article represents an update of an article previously published in 2006 with the same title (Zanetti and Saupe, Radiologe 46:79-89, 2006).