Subacute and chronic bone infections: diagnosis using In-111, Ga-67 and Tc-99m MDP bone scintigraphy, and radiography.

The usefulness of indium-111 white blood cell scintigraphy in the diagnosis of subacute or chronic bone infection was examined in 21 orthopedic patients. In-111 WBC imaging was compared with gallium-67 and technetium-99m methylene diphosphonate skeletal scintigraphy and bone radiography, all studies being performed within 1 week. In-111 WBC scintigraphy showed no definite advantage over Ga-67 scintigraphy in the identification of chronic bone infection. The two tests had the same sensitivity (80%) and similar specificity (In-111 WBC 75%, Ga-67 83%; difference not significant). Bone radiography had a sensitivity of 60% and a specificity of 67%. A negative Tc-99m MDP bone scintigram ruled out infection (sensitivity 100%), but because of low specificity (25%), final evaluation required performance of Ga-67 or In-111 WBC scintigraphy.