Detection of metallic implant-associated infections with FDG PET in patients with trauma: correlation with microbiologic results.

Abstract

To prospectively evaluate the value of positron emission tomography (PET) with fluorine 18 fluorodeoxyglucose (FDG) in the detection of metallic implant-associated infections in patients with trauma. Twenty-nine partial-body FDG PET scans in 22 patients suspected of having metallic implant-associated infections were obtained prior to surgery. In two of the 22 patients, data were acquired with a combined PET-CT in-line system. Soft-tissue and bone infections were evaluated. PET scans were analyzed by two experienced nuclear medicine physicians first separately and then in consensus. Disease status was defined on the basis of the results of microbiologic evaluation of surgical specimens together with intraoperative findings. Sensitivities, specificities, accuracies, interobserver variability (determination of kappa values), and receiver operating characteristic curves were obtained. Of 29 PET scans, 14 were true-positive, 14 were true-negative, and one was false-positive. Sensitivity, specificity, and accuracy were 100%, 93.3%, and 97%, respectively, for all PET data; 100%, 100%, and 100%, respectively, for the central skeleton; and 100%, 87.5%, and 95%, respectively, for the peripheral skeleton. The degree of overall interobserver concordance was high (kappa = 0.96). FDG PET appears to be a sensitive and specific method for the detection of infectious foci due to metallic implants in patients with trauma.