Bone scintigraphy findings of chronic recurrent multifocal osteomyelitis

Learning Objectives 1. Review the scintigraphic patterns of chronic recurrent multifocal osteomyelitis (CRMO). 2. Emphasize the value of bone scan in diagnosis of CRMO. 3. Illustrate the importance of performing whole-body scans in children presenting with unifocal symptoms.

Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory bone disease of unknown etiology. It affects predominantly children and adolescents, and occurs mostly in females. It is characterized by insidious onset of pain and swelling, fluctuating clinical course of relapses and remissions. Typically several bones are affected, either synchronous or metachronous. Bilateral involvement is common. CRMO most commonly affects the metaphysis of long bones, especially tibia, femur, and clavicle. Spine, pelvis, ribs and sternum may also be affected. CRMO is a diagnosis of exclusion. The differential diagnosis includes infectious osteomyelitis, bone malignancy, and other inflammatory arthritis. Although lesions are mostly multiple, patients may present with a single symptomatic focus. Radiographs may be negative at early disease. Bone scan is useful in determining the presence of abnormality, extent of disease. It can reveal areas that are more surgically accessible, as confirmatory biopsy will be required in many patients