ObjectiveTo investigate the imaging characteristics of gallium-68 labeled fibroblast activation protein inhibitor (68Ga-FAPI)-positron emission tomography/magnetic resonance (PET/MR) imaging in patients with liver fibrosis or liver tumor. MethodsThirteen patients with suspected liver tumor who underwent 68Ga-FAPI-PET/MR examination from May 2020 to April 2021 were retrospectively analyzed. Maximum standard uptake value (SUVmax) was investigated. All patients underwent liver surgery or biopsy. Scheuer scoring system was used to evaluate the liver fibrosis. The imaging characteristics of liver fibrosis or liver tumor were analyzed. ResultsThe liver fibrosis was confirmed in 6 patients, including 1 case of S2, 2 cases of S3, and 3 cases of S4. Among them, 4 patients had increased uptake of 68Ga-FAPI, with patchy or diffuse abnormal concentration of liver, and the SUVmax was 7.9±3.1. The liver imaging of the other 2 patients with liver fibrosis showed no obvious radioactive concentration. In addition, 2 patients were diagnosed with hepatocellular carcinoma, its SUVmax was 7.2 and 6.1; 1 patient was diagnosed with hepatobiliary duct carcinoma and its SUVmax was 13.8. Moreover, increased uptake of 68Ga-FAPI was observed in 4 patients with metastatic liver cancer, with SUVmax of 6.7±2.7. ConclusionBoth liver fibrosis and liver tumor are suitable for 68Ga-FAPI-PET/MR examination, which have different imaging characteristics.