The negative impact of fatty liver on maximum standard uptake value of liver on FDG PET

Purpose: The purpose of the study is to evaluate the impact of fatty liver on maximum standard uptake value (SUVmax) of liver on 2-fluoro-2-deoxy- d-glucose (FDG) positron emission tomography (PET). Materials and methods: A total of 173 consecutive healthy subjects were retrospectively recruited for analysis. Subjects with acute renal disease, chronic renal disease, or malignancy were excluded. Demographic data were collected from chart records. All subjects performed whole-body FDG PET, sonography of liver, and glutamic pyruvic transaminase (GPT) level. The SUVmax of liver on FDG PET was calculated. The relationship between the severity of fatty liver and SUVmax of liver on FDG PET was analyzed. Results: There were significant differences in SUVmax of liver on FDG PET in four groups: no fatty liver, mild-degree, moderate-degree, and severe-degree fatty liver on sonography diagnosis (P=041). After adjusting for possible covariates age, sex, body mass index, and GPT, there was a significantly negative correlation between the severity of fatty liver and SUVmax of liver on FDG PET (β=-20, P<.001). Conclusion: Based on the results of this study, the liver cannot be used as a comparator of extrahepatic foci of equivocal increased FDG activity in patients with fatty liver disease.