Impact of age on FDG uptake in the liver on PET scan

The intensity of physiological 18F-2-deoxy-D-glucose (FDG) uptake in the liver varies. It is important to be familiar with the varying degree of FDG accumulation in the liver that represents normal distribution and physiological changes, before attempting to interpret whole-body positron emission tomography (PET) imaging for malignancy detection. The aim of this study is to evaluate the possible factors influencing the intensity of physiological FDG uptake in the liver on FDG PET imaging.

From 2005 to 2007, a total of 339 consecutive healthy subjects, referred from the Department of Community Medicine and Health Examination Center of our hospital for health screening, were retrospectively recruited for analysis. Demographic data were collected from chart records. Whole body FDG PET imaging and serologic determination of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection status were performed on all subjects. The mean and maximum standard uptake values (SUVs) of the liver were calculated. The relationships between sex, age, HBV and HCV infection status, and SUVmax and SUVmean of the liver on FDG PET imaging were evaluated.

There was no statistically significant relationship between sex, HBV and HCV infection status and maximum standard uptake value (SUVmax) or mean standard uptake value (SUVmean) of the liver. After adjusting for covariables, age was a statistically significant predictor of SUVmax (B=0.18; P= .001) and SUVmean (B=0.16; P= .004) of the liver on FDG PET imaging.

Age has a significant and positive impact on both maximum and mean standard uptake values of the liver on FDG PET imaging. High physiological background FDG uptake will reduce diagnostic sensitivity and accuracy for malignancy detection in the liver.