Myositis Ossificans of the Psoas Muscle After Compression Fracture of Lumbar Spine: CT and MR Imaging Findings

plastic formation of heterotopic bone in the skeletal muscle (1-5). Although myositis ossificans can occur anywhere in the body following trauma, it is predominantly localized to high-risk sites of injury, such as large muscles of the extremities (2-4). Most lesions are related to direct major trauma or repeated minor injuries. No history of trauma is present in approximately 40% of patients (2, 3). In the English medical literature, there are many reports on myositis ossificans that included radiographic, CT and MR imaging findings (1-7). The CT and MR imaging findings of myositis ossificans involving the psoas muscle have been reported twice (2, 7). We could not identify any reports on CT and MR imaging findings of the psoas muscle following lumbar spine fracture in the radiological literature. We report the CT and MR imaging findings of a 64-year-old man who developed myositis ossificans of the psoas muscle following lumbar spine fracture.