Technetium Tc 99m diphosphonate bone scan. False-normal findings in elderly patients with hematogenous vertebral osteomyelitis.

Hematogenous osteomyelitis is usually diagnosed by an abnormal technetium Tc 99m diphosphonate bone scan in symptomatic patients who have positive blood cultures. False-normal 99mTc bone scans have been described recently in neonates with biopsy-proved osteomyelitis. This phenomenon seems to be extremely rare in adults. Two elderly patients with hematogenous vertebral osteomyelitis had normal technetium Tc 99m diphosphonate bone scans when first evaluated. In both cases the bone scans became abnormal four to six weeks after onset of symptoms and two to four weeks after the initial normal results of the study. When suggested by the clinical picture, hematogenous osteomyelitis cannot be ruled out by a normal 99mTc bone scan at any age. Gallium scan, computed tomographic scan, or bone biopsy can be helpful in such cases.