Magnetic resonance imaging of sports-related muscle injuries.

Magnetic resonance imaging (MRI) is increasingly being used to evaluate muscle injuries because of its unparalleled anatomic resolution and high sensitivity in detecting acute and chronic soft-tissue abnormalities. These features allow detection of characteristic injury patterns that lead to accurate diagnoses and grading of severity. The precise assessment of muscle injuries with MRI plays an important role in determining the treatment plan and prognosis of injured athletes. The article begins with a review of the anatomy and MRI characteristics of normal muscle. The general mechanisms of muscle injury and associated MRI findings are discussed, with emphasis on the most common injuries in both the upper and lower extremities. Several mimics of muscle injury are briefly outlined.