Understanding the anatomy, injury patterns, and surgical procedures is essential for image interpretation. While direct evaluation of the rotator cuff cannot be made, radiographs of the shoulder provide the initial evaluation of the osseous abnormalities associated with rotator cuff impingement. MR imaging is considered the study of choice for the evaluation of the shoulder because of the comprehensive assessment of both bone and soft-tissue abnormalities. MR can accurately evaluate the size and shape of tendon tears, tendon tear retraction, and tendon and muscle quality. Computed tomography is an excellent modality for the evaluation of osseous detail and detection of gas and calcium deposition; however, conventional CT is much less sensitive for bone marrow edema detection and soft tissue detail of the rotator cuff. Ultrasound can assess the rotator cuff with results similar to MRI, but cannot evaluate osseous structures.