Quantifying [18F]fluorodeoxyglucose uptake in the arterial wall: the effects of dual time-point imaging and partial volume effect correction

Abstract

Purpose: The human arterial wall is smaller than the spatial resolution of current positron emission tomographs. Therefore, partial volume effects should be considered when quantifying arterial wall 18F-FDG uptake. We evaluated the impact of a novel method for partial volume effect (PVE) correction with contrast-enhanced CT (CECT) assistance on quantification of arterial wall 18F-FDG uptake at different imaging time-points. Methods: Ten subjects were assessed by CECT imaging and dual time-point PET/CT imaging at approximately 60 and 180 min after 18F-FDG administration. For both time-points, uptake of 18F-FDG was determined in the aortic wall by calculating the blood pool-corrected maximum standardized uptake value (cSUVMAX) and cSUVMEAN. The PVE-corrected SUVMEAN (pvcSUVMEAN) was also calculated using 18F-FDG PET/CT and CECT images. Finally, corresponding target-to-background ratios (TBR) were calculated. Results: At 60 min, pvcSUVMEAN was on average 3.1 times greater than cSUVMAX (P <.0001) and 8.5 times greater than cSUVMEAN (P <.0001). At 180 min, pvcSUVMEAN was on average 2.6 times greater than cSUVMAX (P <.0001) and 6.6 times greater than cSUVMEAN (P <.0001). Conclusion: This study demonstrated that CECT-assisted PVE correction significantly influences quantification of arterial wall 18F-FDG uptake. Therefore, partial volume effects should be considered when quantifying arterial wall 18F-FDG uptake with PET.