Objective: Over the last decade, the contribution of 18F-FDG (FDG) PET/CT imaging to the diagnosis of large vessel vasculitis has been widely investigated. The aim of this study was to evaluate a more extensive role for PET/CT in grading vascular inflammation in patients with different clinical stages of disease. Methods: The images of 66 PET/CT studies of 34 patients, performed at diagnosis and/or during follow-up were reviewed. FDG uptake in different regions of aorta and in its major branches was visually (regional Score: rS) and semiquantitatively (regional SUVmean: rSUV) assessed. The global vascular uptake was also evaluated for each study by summing all rSs (summed Score; sS) and averaging rSUVs (averaged SUV; aSUV). FDG uptake in 15 PET/CT studies of control age-matched subjects without signs or symptoms of vasculitis was also analyzed. Results: Higher levels of regional and global FDG uptake were found at diagnosis in comparison with follow-up studies of 12 patients with complete longitudinal observation (p value range 0.0552–0.0026). In the latter group high values were generally observed when disease relapse or incomplete response to therapy (active disease) occurred, whereas lower uptake was found in studies of remitted patients (p = 18F-FDG PET/CT has a promising role in grading inflammation in patients with large arteries vasculitis. Nevertheless, a cut-off based analysis of FDG vascular uptake is not sufficient to separate patients with active and inactive disease during follow-up.
- Large vessel vasculitis
- SUV analysis
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging