Variations of the liver standardized uptake value in relation to background blood metabolism: An 2-[(18)F]Fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography study in a large population from China

To investigate the influence of background blood metabolism on liver uptake of 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) and search for an appropriate corrective method. Positron emission tomography/computed tomography (PET/CT) and common serological biochemical tests of 633 healthy people were collected retrospectively. The mean standardized uptake value (SUV) of the liver, liver artery, and portal vein (i.e., SUV(L,) SUV(A), and SUV(P)) were measured. SUV(L/A) was calculated as SUV(L)/SUV(A), while SUV(L/P) was calculated as SUV(L)/SUV(P.) SUV of liver parenchyma (SUV(LP)) was calculated as SUV(L) − .3 × (.75 × SUV(P) + .25 × SUV(A)). The coefficients of variation (CV) of SUV(L), SUV(L/A), SUV(L/P), and SUV(LP) were compared to assess their interindividual variations. Univariate and multivariate analyses were performed to identify vulnerabilities of these SUV indexes to common factors assessed using serological liver functional tests. SUV(LP) was significantly larger than SUV(L) (2.19 ± .497 vs 1.88 ± .495, P < .001), while SUV(L/P) was significantly smaller than SUV(L) (1.72 ± .454 vs 1.88 ± .495, P < .001). The difference between SUV(L/A) and SUV(L) was not significant (1.83 ± .500 vs 1.88 ± .495, P = .130). The CV of SUV(LP) (22.7%) was significantly smaller than that of SUV(L) (22.7%:26.3%, P < .001), while the CVs of SUV(L/A) (27.2%) and SUV(L/P) (26.4%) were not different from that of SUV(L) (P = .429 and .929, respectively). Fewer variables independently influenced SUV(LP) than influenced SUV(L), SUV(L/A), and SUV(L/P); Only aspartate aminotransferase, body mass index, and total cholesterol, all P-values <.05. The activity of background blood influences the variation of liver SUV. SUV(LP) might be an alternative corrective method to reduce this influence, as its interindividual variation and vulnerability to effects from common factors of serological liver functional tests are relatively lower than the commonly used SUV(L).