MRI of the shoulder with its excellent soft tissue discrimination, and high spatial resolution offers the best noninvasive way to study the shoulder. MRI images of the bone, muscles and tendons of the glenohumeral joint can be obtained in any oblique planes and projections. MRI gives excellent depiction of rotator cuff tears, injuries to the biceps tendon and damage to the glenoid labrum. Shoulder MRI is better than ultrasound imaging at depicting structural changes such as osteophytic spurs, ligament thickening, and acromial shape that may have predisposed to tendon degeneration.
A dedicated shoulder coil and careful patient positioning in external rotation with the shoulder as close as reasonably possible to the center of the magnet is necessary for a good image quality. If possible, the opposite shoulder should be lifted up, so that the patient lies on the imaged shoulder in order to rotate and fix this shoulder to reduce motion during breathing.
Axial, coronal oblique, and sagittal oblique proton density with fat suppression, T2 and T1 provide an assessment of the rotator cuff, biceps, deltoid, acromio-clavicular joint, the glenohumeral joint and surrounding large structures. If a labral injury is suspected, a Fat Sat gradient echo sequence is recommended. In some cases, a direct MR shoulder arthrogram with intra-articular injection of dilute gadolinium or an indirect arthrogram with imaging 20 min. after intravenous injection may be helpful.

See also Imaging of the Extremities.