Magnetic resonance imaging of the shoulder in the primary care setting.

MRI is an excellent noninvasive method of diagnosing difficult shoulder problems. Although usually not needed for classic primary impingement syndrome or clinically obvious rotator cuff tears, MRI may be helpful in diagnosing secondary causes of impingement or in some cases involving partial rotator cuff tears. Some surgeons may use MRI preoperatively to define the extent of the rotator cuff tear, as this may alter their surgical approaches.