Scan-rescan measurement repeatability of ¹⁸F-FDG PET/MR imaging of vascular inflammation

Non-invasive positron emission tomography (PET) of vascular inflammation and atherosclerotic plaque by identifying increased uptake of ¹⁸F-fluordeoxyglucose (¹⁸F-FDG) is a powerful tool for monitoring disease activity, progression, and its response to therapy. ¹⁸F-FDG PET/computed tomography (PET/CT) of the aorta and carotid arteries has become widely used to assess changes in inflammation in clinical trials. However, the recent advent of hybrid PET/magnetic resonance (PET/MR) scanners has advantages for vascular imaging due to the reduction in radiation exposure and improved soft tissue contrast of MR compared to CT. Important for research and clinical use is an understanding of the scan-rescan repeatability of the PET measurement. While this has been studied for PET/CT, no data is currently available for vascular PET/MR imaging. In this study, we determined the scan-rescan measurement repeatability of ¹⁸F-FDG PET/MR in the aorta and carotid arteries was less than 5%, comparable to similar findings for ¹⁸F-FDG PET/CT.