Chronic recurrent multifocal osteomyelitis: A rare entity.

INTRODUCTION: Chronic recurrent multifocal osteomyelitis (CRMO) is an auto-inflammatory disease which is characterised by non-infectious bone lesions at multiple sites which have a relapsing nature. Our aim is to examine the role of radiology in diagnosis and management of CRMO patients who have been managed at the Mater Children's Hospital.

METHODS: This is a retrospective analysis of patients who have been managed with CRMO at the Mater Hospital since 2002. Inclusion criteria included a final diagnosis of CRMO. Exclusion criteria were a diagnosis more likely than CRMO. Medical images for each patient were evaluated for lesion features, location of lesion, number of bony lesions and whether or not the radiographic appearance would be characteristic of CRMO.

RESULTS: Initially, 17 patients were included in the study; however, seven patients were excluded due to a more likely alternative diagnosis. In total, 24 lesions were detected; the most common anatomical sites were the spine (25%), feet (25%), ribs (16.7%) and femur (12.5%). Plain radiography lacked sensitivity, but it was important in initial screening and evaluating progress of lesions. MRI is important for targeted investigation and further evaluation of lesions. Bone scintigraphy is useful for detecting other affected sites. Due to the exposure to radiation, computed tomography is generally avoided.

CONCLUSIONS: The combination of imaging modalities plays a large role in CRMO diagnosis. CRMO lesions usually appear ill defined with no pathognomonic features. The distribution of bony lesions can aid diagnosis, with lower limbs and clavicles commonly affected.