The accuracy of diagnostic imaging for the assessment of chronic osteomyelitis: A systematic review and meta-analysis

Background: A variety of diagnostic imaging techniques is available for excluding or confirming chronic osteomyelitis. Until now, an evidence-based algorithmic model for choosing the most suitable imaging technique has been lacking. The objective of this study was to determine the accuracy of current imaging modalities in the diagnosis of chronic osteomyelitis. Methods: A systematic review and meta-analysis of the literature was conducted with a comprehensive search of the MEDLINE, EMBASE, and Current Contents databases to identify clinical studies on chronic osteomyelitis that evaluated diagnostic imaging modalities. The value of each imaging technique was studied by determining its sensitivity and specificity compared with the results of histological analysis, findings on culture, and clinical follow-up of more than six months. Results: A total of twenty-three clinical studies in which the accuracy was described for radiography (two studies), magnetic resonance imaging (five), computed tomography (one), bone scintigraphy (seven), leukocyte scintigraphy (thirteen), gallium scintigraphy (one), combined bone and leukocyte scintigraphy (six), combined bone and gallium scintigraphy (three), and fluorodeoxyglucose positron emission tomography (four) were included in the review. No meta-analysis was performed with respect to computed tomography, gallium scintigraphy, and radiography. Pooled sensitivity demonstrated that fluorodeoxyglucose positron emission tomography was the most sensitive technique, with a sensitivity of 96% (95% confidence interval, 88% to 99%) compared with 82% (95% confidence interval, 70% to 89%) for bone scintigraphy, 61% (95% confidence interval, 43% to 76%) for leukocyte scintigraphy, 78% (95% confidence interval, 72% to 83%) for combined bone and leukocyte scintigraphy, and 84% (95% confidence interval, 69% to 92%) for magnetic resonance imaging. Pooled specificity demonstrated that bone scintigraphy had the lowest specificity, with a specificity of 25% (95% confidence interval, 16% to 36%) compared with 60% (95% confidence interval, 38% to 78%) for magnetic resonance imaging, 77% (95% confidence interval, 63% to 87%) for leukocyte scintigraphy, 84% (95% confidence interval, 75% to 90%) for combined bone and leukocyte scintigraphy, and 91% (95% confidence interval, 81% to 95%) for fluorodeoxyglucose positron emission tomography. The sensitivity of leukocyte scintigraphy in detecting chronic osteomyelitis in the peripheral skeleton was 84% (95% confidence interval, 72% to 91%) compared with 21% (95% confidence interval, 11% to 38%) for its detection of chronic osteomyelitis in the axial skeleton. The specificity of leukocyte scintigraphy in the axial skeleton was 60% (95% confidence interval, 39% to 78%) compared with 80% (95% confidence interval, 61% to 91%) for the peripheral skeleton. Conclusions: Fluorodeoxyglucose positron emission tomography has the highest diagnostic accuracy for confirming or excluding the diagnosis of chronic osteomyelitis. Leukocyte scintigraphy has an appropriate diagnostic accuracy in the peripheral skeleton, but fluorodeoxyglucose positron emission tomography is superior for detecting chronic osteomyelitis in the axial skeleton.