Skeletal Muscle Disease: Imaging Findings Simplified.

Skeletal muscle is a major anatomic structural component of the human body. Myopathy, defined as skeletal muscle disease, may offend any of the body's 650 muscles and encompasses an extended array of acute and chronic abnormalities. Muscle disease can be categorized according to etiology as congenital, traumatic, infectious, or neoplastic. The concept of the diversity of multiple muscular disease processes signifies an important role for imaging in the detection and characterization of myopathy. However, despite the exquisite physiological properties of skeletal muscle, muscle imaging has not received attention equal to that of bones and joints. Accordingly, this article provides an indication of the most suitable imaging modalities for myopathy and reviews a multitude of primary and systemic muscle derangements, with an emphasis on magnetic resonance (MR) imaging findings. Because these patterns of MR imaging abnormality bespeak the widespread nature of myopathy, we illustrate typical examples of muscle disease processes to simplify diagnosis.