Comparison of 18 F-FDG, 18 F-Fluoroacetate, and 18 F-FEPPA for Imaging Liver Fibrosis in a Bile Duct-Ligated Rat Model.

Developing sensitive diagnostic methods for a longitudinal evaluation of the status of liver fibrosis is a priority. This study is aimed at assessing the significance of longitudinal positron emission tomography (PET) imaging with 18 F-labeling tracers for assessing liver fibrosis in a rat model with bile duct ligation (BDL). Twenty-one 6-week-old Sprague-Dawley male rats were used in this study. Longitudinal PET images using [ 18 F]N-2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide ([ 18 F]FEPPA) ( n = 3), [ 18 F]fluoroacetate ([ 18 F]FAc) ( n = 3), and 18F-fluoro-2-deoxy-D-glucose ([ 18 F]FDG) ( n = 3) were obtained at 0, 1, and 2 weeks after BDL. Biochemical assays, histological assays, immunohistochemical staining assays, and next generation sequencing analyses were also performed at 0 ( n = 3), 1 ( n = 3), 2 ( n = 3), and 3 ( n = 3) weeks after BDL, which demonstrated the severe damage in rat livers after BDL. Regarding [ 18 F]FEPPA and [ 18 F]FDG, there was a significantly higher uptake in the liver after BDL (both P < 0.05), which lasted until week 2. However, the uptake of [ 18 F]FAc in the liver was not significantly different before and after BDL ( P = 0.28). Collectively, both [ 18 F]FEPPA and [ 18 F]FDG can serve as sensitive probes for detecting the liver fibrosis. However, [ 18 F]FAc is not recommended to diagnose liver fibrosis.