Many musculoskeletal conditions have in the past been best defined on a clinical basis. However, because of pain, limitation of motion and hematomas, tendon ruptures can often be misdiagnosed clinically and it would be quite helpful to the clinician to have a noninvasive imaging technique. This communication defines the role of MRI in the early diagnosis of a nontraumatic rupture of the quadriceps tendons bilaterally in a patient with renal failure and known secondary hyperparathyroidism. The imaging techniques accurately defined the presence of hemorrhage extending into muscle from the ruptured tendons as well as the actual site and extent of tendon rupture. Since tendons have low mobile proton content and have low signal on MRI--disruptions are easily seen--MRI is the ideal noninvasive imaging technique for tendon injury, acute.