Cold Defects in ln-111 Labeled Leukocyte Imaging of Osteomyelitis in the Axial Skeleton

Use of In-111 oxine labeled leukocytes in the detection of osteomyelitis of the peripheral skeleton usually presents few problems. However, the diagnosis of osteomyelitis is more difficult in marrow-bearing areas because uptake of indium is normal. Sixty-one In-111 labeled leukocyte scans, that had been performed to exclude osteomyelitis of the axial skeleton, pelvis, and proximal long bones, were reviewed. Eight cold defects were identified at sites of suspected osteomyelitis. Five of these were surgically proven osteomyelitis. Nineteen percent of all cases of osteomyelitis in these areas (5 of 26) presented as cold defects. This incidence of osteomyelitis presenting as cold defects is higher than previously reported. Therefore, the possibility of osteomyelitis should be strongly considered when a cold defect is identified in red marrow areas.