COMPARISON OF THE TWO METHODS FOR THE VASCULAR INFLAMMATION USING FDG PET/CT OF THE AORTA

Abstract

18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is a state-of-the-art imaging technique that assesses inflammatory activity in the aorta. The current standard methodology involves quantification of FDG uptake on every 4-8 mm cross-sectional slices of three aortic regions (ascending, arch and descending). The resulting FDG standard uptake values (SUVs) for each slice within each aortic region are averaged and corrected for blood background activity to obtain a target-to background ratio (TBR) for the mean and maximal values of each aortic region of interest. On average, this method calls for over 100 slices to be traced for total aortic quantification. This methodology is time-consuming and cumbersome. We developed a simpler methodology in which each aortic region of interest is traced only twice longitudinally, SUVs averaged, and TBR values computed (fig). This new, less laborious methodology would greatly facilitate large-scale studies using FDG-PET/CT. In this study we aimed at a) testing the correlation between the new method of quantifying vascular inflammation using FDG-PET/CT and the current standard method; and b) testing the reproducibility of the new method.