Two-time-point FDG PET/CT: liver SULmean repeatability.

OBJECTIVE. The purpose of this study was to evaluate the repeatability of liver mean standardized uptake value normalized to lean body mass (SULmean) in the same patients at different time points within the right lobe of the liver at 18F-FDG PET/CT, in a clinical setting. MATERIALS AND METHODS. Two PET/CT studies performed on two different dates from each of 130 patients who had normal livers according to structural imaging were included in this reader study. The mean (± SD) length of time between the studies was 235 ± 192 days. SULmean was measured with a 30-mm diameter spherical volume of interest (VOI) placed within the right lobe of the liver (above, below, and at the level of the main portal vein) by two expert readers. ANOVA, intraclass correlation coefficient (ICC), and Bland-Altman analysis were performed. RESULTS. The ICC for the first and second set of studies varied between 0.487 and 0.535 for reader 1 and between 0.472 and 0.545 for reader 2. The mean percentage variation for SULmean between t...