Positron emission tomography/computed tomography for diagnosis of prosthetic valve endocarditis: increased valvular 18F-fluorodeoxyglucose uptake as a novel major criterion

Another potential step to improve prosthetic heart valve endocarditis imaging with 18F-FDG PET/CT

“…These criteria enable a diagnostic probability classification as definite, possible, or rejected endocarditis. 7 Further, in the study of Saby et al, 6 quantification of prosthetic valve FDG uptake with SUV max and TBR was highly variable among the three categories of definite, possible, or rejected PVE. While the mean value of SUV max was significantly higher in definite PVE (&4.3) as compared to possible and rejected PVE, respectively (&3.8 and &3.6), a high overlap among individual measurements widely ruled out the identification of a definite threshold to differentiate between true PVE, sterile inflammation, and no PVE.…”

“…There are important confounding factors in the assessment of PVE with 18 F-FDG PET/CT imaging that need to be given particular attention. The study of Saby et al 6 for example may have underestimated the falsepositive rate as the testing was in patients with high pretest probability for PVE. Thus, the diagnostic value of 18 F-FDG PET/CT in the identification of PVE still needs further investigations in the clinically more relevant population with intermediate probability for the presence of PVE.…”

“…1 Such finding emphasizes that even uninfected PHVs may have a certain amount of sterile inflammation, reflecting post-surgical tissue response and/or a mild foreign body reaction depending on the post-interventional period. Of interest, Saby et al 6 studied 72 consecutive patients with suspicion of having PVE with 18 F-FDG PET/CT. They reported sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy to be 73, 80, 85, 67, and 76%, respectively.…”

Nuclear imaging for patients with a suspicion of infective endocarditis: Be part of the team!

“…The probability of IE is high in the presence of intense, focal FDG uptake in perivalvular regions (max. SUV [5][6], but it can be difficult to rule out IE in the presence of moderate valvular FDG uptake. Several aspects can be suggestive of IE: focal or heterogeneous perivalvular FDG uptake, location of the signal in the aorto-mitral trigone, association of FDG uptake with an infiltrative process on echocardiography or CT. None of these aspects are, however, highly specific for infection.…”

Quantifying FDG uptake to diagnose cardiac device infections: When and how should we do it?

“…4 Consequently, the recent 2015 European Society of Cardiology (ESC) Guidelines for the management of infective endocarditis (IE) have added FDG PET imaging, with the argument that FDG PET can improve the sensitivity of the modified Duke criteria when there is possible IE or rejected IE with a high suspicion. 5 The ESC guidelines propose that in the setting of suspected endocarditis on a prosthetic valve, abnormal FDG activity or radiolabeled leucocyte SPECT/CT should be considered a major criterion, if the prosthesis was implanted [3 months previously.…”