%0 Journal Article %A François Rouzet %A Renata Chequer %A Khadija Benali %A Laurent Lepage %A Walid Ghodbane %A Xavier Duval %A Bernard Iung %A Alec Vahanian %A Dominique Le Guludec %A Fabien Hyafil %T Respective Performance of 18F-FDG PET and Radiolabeled Leukocyte Scintigraphy for the Diagnosis of Prosthetic Valve Endocarditis %D 2014 %R 10.2967/jnumed.114.141895 %J Journal of Nuclear Medicine %P 1980-1985 %V 55 %N 12 %X Echocardiography plays a key role in the diagnosis of infective endocarditis (IE) but can be inconclusive in patients in whom prosthetic valve endocarditis (PVE) is suspected. The incremental diagnostic value of 18F-FDG PET and radiolabeled leukocyte scintigraphy in IE patients has already been reported. The aim of this study was to compare the respective performance of 18F-FDG PET and leukocyte scintigraphy for the diagnosis of PVE in 39 patients. Methods: 18F-FDG PET and leukocyte scintigraphy were performed on 39 consecutive patients admitted because of clinically suspected PVE and inconclusive echocardiography results. The results of 18F-FDG PET and leukocyte scintigraphy were analyzed separately and retrospectively by experienced physicians masked to the results of the other imaging technique and to patient outcome. The final Duke–Li IE classification was made after a 3-mo follow-up. Results: Of the 39 patients, 14 were classified as having definite IE, 4 as having possible IE, and 21 as not having IE. The average interval between 18F-FDG PET and leukocyte scintigraphy was 7 ± 7 d. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 93%, 71%, 68%, 94%, and 80%, respectively, for 18F-FDG PET and 64%, 100%, 100%, 81%, and 86%, respectively, for leukocyte scintigraphy. Discrepancies between the results of 18F-FDG PET and leukocyte scintigraphy occurred in 12 patients (31%). In patients with definite IE, 5 had true-positive 18F-FDG PET results but false-negative leukocyte scintigraphy results. Of these 5 patients, 3 had nonpyogenic microorganism IE (Coxiella or Candida). Of patients for whom endocarditis had been excluded, 6 had true-negative leukocyte scintigraphy results but false-positive 18F-FDG PET results. These 6 patients had been imaged in the first 2 mo after the last cardiac surgery. The last patient with a discrepancy between 18F-FDG PET and leukocyte scintigraphy was classified as having possible endocarditis and had positive 18F-FDG PET results and negative leukocyte scintigraphy results. Conclusion: 18F-FDG PET offers high sensitivity for the detection of active infection in patients with suspected PVE and inconclusive echocardiography results. Leukocyte scintigraphy offers a higher specificity, however, than 18F-FDG PET for diagnosis of IE and should be considered in cases of inconclusive 18F-FDG PET findings or in the first 2 mo after cardiac surgery. %U https://jnm.snmjournals.org/content/jnumed/55/12/1980.full.pdf