This project aims to comprehensively analyze the diagnostic efficacy of SUVmax, SUVean, TLG, MTV, etc. in gastric cancer through 18F-FAPI-04 PET/CT imaging combined with serum tumor markers and other methods, and construct a molecular imaging diagnostic model for gastric cancer; Next, analyze the diagnostic efficacy of 18F-FAPI-04 PET/CT and PET/MR multimodal imaging in evaluating SUVmax, PET/CT-PCI, and PET/MR-PCI for gastric cancer peritoneal metastasis, and construct a molecular imaging diagnostic model for gastric cancer peritoneal metastasis; Exploring the clinical value of 18F-FAPI-04 PET/CT and PET/MR imaging in the diagnosis and staging of gastric cancer.

Inclusion Criteria:

1. Age over 18 years old;
2. Diagnosed as a patient with gastric cancer;
3. Receive FAPI PET/CT and FDG PET/CT imaging within one week;
4. Perform serum tumor marker testing one week before and after scanning

Exclusion Criteria:

1. History of other malignant tumors;
2. Patients with severe infections, severe underlying diseases such as heart, kidney, and liver;
3. Patients with contraindications for PET-CT examination, poor physical condition, and inability to tolerate the examination;
4. Patients with unorganized pathology or incomplete clinical data

Gastric cancer