The utility of bone scans in rheumatology

Purpose: Bone scanning is the most common diagnostic imaging service requested by Australian rheumatologists, who order $50,000 (Australian) worth of bone scans annually. Methods: To determine why rheumatologists request bone scans and how they affect their patient management, the authors administered a two-part prospective survey before and after every bone scan ordered by four rheumatologists during a 6-month period in 1996. Results: A total of 136 bone scans were requested. The primary indications for scanning were to confirm a clinical diagnosis (38%), to exclude a diagnosis (34%), and to localize the site of pain (17%). The common diseases that rheumatologists were attempting to confirm or exclude with bone scanning were inflammatory arthritis, malignancy, and fracture. However, the most common provisional and final diagnosis was soft tissue rheumatism (18%), followed by inflammatory arthritis (15%) and osteoarthritis (11%). Bone scans were successful in excluding a diagnosis in 87% and confirming a diagnosis in 80%. In 32%, bone scans altered the clinical diagnosis, and in 43% they changed the course of disease management. Bone scan results prevented further investigations in 60%.