title: Respective performance of 18F-FDG PET and radiolabeled leukocyte scintigraphy for the diagnosis of prosthetic valve endocarditis.
abstract: 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 (18)F-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 (18)F-FDG PET and leukocyte scintigraphy for the diagnosis of PVE in 39 patients.
  
  
  METHODS
  (18)F-FDG PET and leukocyte scintigraphy were performed on 39 consecutive patients admitted because of clinically suspected PVE and inconclusive echocardiography results. The results of (18)F-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 (18)F-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 (18)F-FDG PET and 64%, 100%, 100%, 81%, and 86%, respectively, for leukocyte scintigraphy. Discrepancies between the results of (18)F-FDG PET and leukocyte scintigraphy occurred in 12 patients (31%). In patients with definite IE, 5 had true-positive (18)F-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 (18)F-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 (18)F-FDG PET and leukocyte scintigraphy was classified as having possible endocarditis and had positive (18)F-FDG PET results and negative leukocyte scintigraphy results.
  
  
  CONCLUSIONS
  (18)F-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 (18)F-FDG PET for diagnosis of IE and should be considered in cases of inconclusive (18)F-FDG PET findings or in the first 2 mo after cardiac surgery.
authors.affiliation: Department of Nuclear Medicine, Bichat University Hospital, Département Hospitalo-Universitaire FIRE, Assistance Publique-Hôpitaux de Paris, University Paris Diderot-Paris 7, Paris, France Inserm Unité Mixte de Recherche 1148, Bichat University Hospital, Paris, France.
authors.forename: François
authors.initials: F
authors.lastname: Rouzet
authors.affiliation: Department of Nuclear Medicine, Bichat University Hospital, Département Hospitalo-Universitaire FIRE, Assistance Publique-Hôpitaux de Paris, University Paris Diderot-Paris 7, Paris, France.
authors.forename: Renata
authors.initials: R
authors.lastname: Chequer
authors.affiliation: Department of Nuclear Medicine, Bichat University Hospital, Département Hospitalo-Universitaire FIRE, Assistance Publique-Hôpitaux de Paris, University Paris Diderot-Paris 7, Paris, France Inserm Unité Mixte de Recherche 1148, Bichat University Hospital, Paris, France.
authors.forename: Khadija
authors.initials: K
authors.lastname: Benali
authors.affiliation: Department of Cardiac Surgery, Bichat University Hospital, Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Lepage
authors.affiliation: Department of Cardiac Surgery, Bichat University Hospital, Paris, France.
authors.forename: Walid
authors.initials: W
authors.lastname: Ghodbane
authors.affiliation: Inserm Clinical Investigation Center 007, Bichat University Hospital, Paris, France; and.
authors.forename: Xavier
authors.initials: X
authors.lastname: Duval
authors.affiliation: Inserm Unité Mixte de Recherche 1148, Bichat University Hospital, Paris, France Department of Cardiac Surgery, Bichat University Hospital, Paris, France Inserm Clinical Investigation Center 007, Bichat University Hospital, Paris, France; and Department of Cardiology, Bichat University Hospital, Département Hospitalo-Universitaire FIRE, Assistance Publique-Hôpitaux de Paris, University Paris Diderot-Paris 7, Paris, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Iung
authors.affiliation: Inserm Unité Mixte de Recherche 1148, Bichat University Hospital, Paris, France Department of Cardiac Surgery, Bichat University Hospital, Paris, France Inserm Clinical Investigation Center 007, Bichat University Hospital, Paris, France; and Department of Cardiology, Bichat University Hospital, Département Hospitalo-Universitaire FIRE, Assistance Publique-Hôpitaux de Paris, University Paris Diderot-Paris 7, Paris, France.
authors.forename: Alec
authors.initials: A
authors.lastname: Vahanian
authors.affiliation: Department of Nuclear Medicine, Bichat University Hospital, Département Hospitalo-Universitaire FIRE, Assistance Publique-Hôpitaux de Paris, University Paris Diderot-Paris 7, Paris, France Inserm Unité Mixte de Recherche 1148, Bichat University Hospital, Paris, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Le Guludec
authors.affiliation: Department of Nuclear Medicine, Bichat University Hospital, Département Hospitalo-Universitaire FIRE, Assistance Publique-Hôpitaux de Paris, University Paris Diderot-Paris 7, Paris, France Inserm Unité Mixte de Recherche 1148, Bichat University Hospital, Paris, France fabien.hyafil@bch.aphp.fr.
authors.forename: Fabien
authors.initials: F
authors.lastname: Hyafil
mesh_terms: D000368:Aged; D004697:Endocarditis, Bacterial / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006098:Granulocytes / Q000000981:diagnostic imaging; D006350:Heart Valve Prosthesis; D006801:Humans; D007962:Leukocytes / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 18F-FDG positron emission tomography; cardiac prosthetic valves; infective endocarditis; radiolabeled leukocyte scintigraphy