Figure 3.

FDG and [⁶⁸Ga]Ga-FAPI-04 PET/CT images in a 42-year-old woman with biopsy-proven gastric adenocarcinoma. The primary lesion in the stomach showed no abnormal FDG uptake ((A,C)—red arrows) with intense [⁶⁸Ga]Ga-FAPI-04 tracer avidity ((B,D)—green arrows). FAPI PET/CT revealed a tracer avid hypodense lesion in segment V of the liver ((B,F)—green arrows), which was not picked up on FDG PET/CT ((E)—red arrow), leading to upstaging of disease. Additionally, the uterus showed no abnormal FDG uptake ((G)—red arrow) but had diffuse intense FAPI uptake ((H)—green arrow), which was interpreted as physiologic/benign uptake.