Inflammatory myopathies: radiologic evaluation.

Clinical evaluation of skeletal muscle in patients with inflammatory myopathies (IM) has long been hampered by difficulty in assessing the morphology and functional integrity of skeletal muscles. Advances in radiologic techniques, particularly MR imaging, have improved the ability to manage patients with neuromuscular disease in general and IM in particular. MR imaging can probe beyond the skin to identify focal muscle structural lesions, determine their extent, characterize their composition, direct invasive procedures, and monitor therapies. This article reviews the clinical, pathologic, and imaging aspects of these diseases.