Dynamic contrast-enhanced subtraction and delayed MRI of gastric tumors: Radiologic-pathologic correlation

Purpose: Our goal was to determine whether dynamic MR subtraction images co uld be used to detect and stage gastric tumors. Method: Dynamic MR subtraction images were prospectively performed in 20 pa tients without gastric lesions and in 39 patients with gastric tumors. The flat- or depressed-type early gastric cancers were excluded. The MR finding s were assessed for layered pattern of the normal gastric wall, detectabili ty of tumors, enhanced pattern of tumor, and depth of the tumor invasion. S urgical specimens were obtained from 30 of the patients with tumors, and hi stopathologic sections were made in the dynamic MR scanning direction. Results: The three-layered structure of the normal gastric wall was apparen t in more of the dynamic MR subtraction images (60%) than of the nonsubtrac tion images (30%) in the control group. All 39 gastric tumors were detected by MRI. The intact inner layers overlying stromal tumors and outer layers interrupted by advanced gastric cancers were clear on the subtracted images . MRI accurately T-sta,oed 88% of the gastric cancers. Conclusion: Dynamic MR subtraction images can be used to identify gastric t umors and to stage gastric cancers.