Brucellosis: appearance on skeletal imaging.

Brucellosis is an endemic disease in the Middle East. Its incidence in Kuwait has increased during the last 5 years. Bone and joint involvement causes major symptoms and disabilities. Radionuclide bone scans are more sensitive than radiographs in detecting these lesions. The aim of this study is to describe the abnormal patterns detected on bone imaging in acute and chronic brucellosis. Tc-99m MDP bone scans of 56 patients with established diagnosis of brucellosis (19 acute and 37 chronic) were retrospectively analyzed. Bone scans were positive in 8 of 19 patients (42%) with acute brucellosis and in 28 of 37 patients (76%) with chronic brucellosis. Six patterns were observed: involvement of an entire body of one or more vertebrae, especially at the lumbar region (50%); sacroiliitis (41%); focal high uptake at the junction of the upper and lateral margins of the vertebra "Caries sign" (27%); multiple costovertebral joints and costochondral junction involvement (19%); involvement of large joints similar to degenerative osteoarthritis (25%); and focal involvement of long bone (11%).