TABLE 2

Interpretation of 18F-FDG PET/CT Combining Visual Grading Score and Uptake Pattern

ParameterDetails
Vascular infection
 Grade 118F-FDG uptake similar to background
 Grade 2*Low 18F-FDG uptake comparable to uptake by inactive muscles and fat, and above background uptake but below liver uptake
 Grade 3*Moderate 18F-FDG uptake clearly visible and higher than uptake by inactive muscles and fat, and similar to liver uptake
 Grade 4*Strong 18F-FDG uptake clearly above liver uptake
 Interpretation
  No vascular infectionGrades 1 and 2
  InflammationGrades 3 and 4 and homogeneous uptake pattern without perigraft soft-tissue involvement
  Vascular infectionGrades 3 and 4 and inhomogeneous uptake pattern with or without perigraft soft-tissue involvement
Endocarditis
 Grade 1No relevant 18F-FDG uptake of heart
 Grade 2†Diffuse 18F-FDG uptake in heart (reflecting normal uptake in myocardium)
 Grade 3Focal 18F-FDG uptake in heart with or without diffuse low-level uptake in myocardium
 Interpretation
  No endocarditisGrade 1
  Evaluation not possibleGrade 2
  EndocarditisGrade 3

  • ↵* Additional “a” for homogeneous 18F-FDG uptake and “b” for inhomogeneous 18F-FDG uptake was registered.

  • ↵† Evaluation of heart valves for endocarditis was not possible because of diffuse myocardial 18F-FDG uptake.