The foundation of successful patient care is an accurate clinical diagnosis. The accomplishment of this goal begins with a complete history and physical examination. If the initial evaluation does not provide the information needed to explain the symptoms, additional diagnostic testing is usually needed. The additional data provided by these tests become useful clinical information only when they are integrated with the patient's history and the results of the physical examination and other ancillary tests. Imaging studies may also be part of the preoperative workup in order to confirm the presence of a pathological condition and to determine its extent. In the past, radiographic imaging studies, such as plain radiography and computed tomography, and radionuclide studies, have played a major role in the diagnostic evaluation of patients who have a musculoskeletal disorder. These studies focused mainly on the detection of osseous abnormalities. With the recent development and implementation of magnetic resonance imaging, it is now possible to evaluate non-invasively the soft-tissue structures of the body, such as muscles, tendons, and ligaments, which are the structures frequently responsible for most of the symptoms in patients who have musculoskeletal dysfunction.