Indium-111 chloride scintigraphy in adult osteomyelitis.

Osteomyelitis is a common clinical problem that may be difficult to diagnose. We compared the performance of indium-111-labeled white cells ([111In]WBC) to 111In chloride ([111In]Cl) in two groups of adult patients suspected to have osteomyelitis or septic arthritis. Using [111In] WBC, 52 scans were performed on 51 patients. Nineteen patients had osteomyelitis. The sensitivity was 84% and specificity 82%. Using [111In]Cl, 48 scans were performed on 47 patients. Twelve had osteomyelitis. Sensitivity was 91%, and specificity was 89%. In each group, one false-negative study occurred in vertebral osteomyelitis. Three false-negative studies using [111In]WBC were due to failure to distinguish between combined bone and soft-tissue infection and soft-tissue infection alone. False-positive studies in both groups were due to overlying soft-tissue infection or inflammatory arthritis. Chi-squared test showed no significant difference in performance between the two agents. Indium-111 chloride is easier to prepare and use than [111In]WBC, which requires a time-consuming labeling process.