Correction of artery images for partial volume effect as a function of diameter and position in the scanner field of view

PET imaging is intensively used in cardiovascular diseases for diagnoses and follow-up. Studying the arteries with PET is very demanding since the radiotracer activity is mainly concentrated in blood and the artery walls are too thin to be distinguished. There are however several approaches used in the clinic to quantify artery inflammation like the standard uptake value (SUV) and the tissue-to-blood ratio (TBR). Prior to quantification, the artery image needs to be corrected for partial volume effect (PVE). In the present work, we report PVE characterization with a cylindrical phantom having 8 sets of cylinders (45 cylinders in total) positioned at different locations in the scanner field of view (FOV), and calculation of the recovery factors for artery PVE correction as a function of diameter and position in the FOV of the PET scanner. Phantom CT and PET images were acquired with a CT low dose for attenuation correction and with an iodine contrast agent to clearly discriminate the cylinders. The contrast agent was mixed with a solution of 18F-FDG for PET measurement. The variation of cylinders intensity as a function of their diameter and position in the FOV were fitted to provide recovery factors for any diameter and position in the FOV. The time activity curves of the aorta and iliac arteries were subsequently corrected for PVE for further quantifications.