title: Osteomyelitis and soft-tissue infection: differential diagnosis with 24 hour/4 hour ratio of Tc-99m MDP uptake.
abstract: The lesion-to-nonlesion 24 hour/4 hour ratio of technetium-99m methylene diphosphonate (MDP) uptake was used to distinguish osteomyelitis from increased bone uptake caused by adjacent soft-tissue infection. In a prospective study, this ratio was measured in 38 patients with 41 sites of increased uptake that were suspected to be osteomyelitis. The mean ratio was 1.18 +/- 0.18 in patients with proved osteomyelitis, which was significantly higher (P less than .001) than that in patients with increased uptake resulting from soft-tissue infection (0.98 +/- 0.05). On the basis of a receiver operating characteristic curve, a ratio of 1.06 was selected as the cutoff for differentiating osteomyelitis from soft-tissue infection. This method resulted in a sensitivity of 82%, a specificity of 92%, and an accuracy of 85%, and it appears to be more reliable than three- and four-phase scintigraphy, which are subjective and nonquantitative techniques.
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007239:Infections / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010019:Osteomyelitis / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D013669:Technetium Tc 99m Medronate / Q000378:metabolism; D013997:Time Factors
chemical_list: D013669:Technetium Tc 99m Medronate