Value of the dynamic and delayed MR sequence with Gd-DTPA in the T-stagingof stomach cancer: correlation with the histopathology

Background: To evaluate the usefulness of dynamic and delayed magnetic reso nance (MR) imaging in the T-staging of stomach cancer and to compare the en hancement pattern of the cancerous lesion and the normal wall. Methods: We performed MR imaging in 46 patients with stomach cancer (includ ing four early gastric cancers and 42 advanced gastric cancers). Axial, sag ittal, or coronal two-dimensional fast low-angle shot) MR images for the wa ter-distended stomach were obtained with dynamic protocol, including precon trast images and images obtained 30, 60, 90, and 240-300 s after intravenou s injection of the 0.1 mM Gd-DTPA/kg solution, We evaluated the thickness, interruption (or not) of the low signal intensity bands, and enhancement pa ttern of the cancerous wall and normal gastric wall. We prospectively evalu ated the depth of cancer invasion, perigastric infiltration (extraserosal i nvasion), perigastric organ invasion, and regional lymph nodes and determin ed tumor staging on MR images. These MR evaluations including MR-determined staging were correlated with the surgicopathologic findings. Results: Stomach cancer was shown as having a thickened wall with a rapid e nhancing pattern after intravenous Gd-DTPA administration. The mucosa (and/ or submucosa) affected by stomach cancer showed an early enhancement patter n (30-90 s after Gd-DTPA administration) in 43 of 46 patients (93%). The no rmal gastric mucosa demonstrated a delayed peak enhancement pattern (>90 s after Gd-DTPA administration) in 29 of 46 patients (63%) and variable enhan cement pattern in 17 of 46 patients (37%). An interrupted low signal intens ity band or highly enhanced tumorous lesion penetrating through the gastric wall was seen in 17 of 19 pT3 patients (90%). Consistency between MR-deter mined staging and surgicopathologic staging occurred in three of four pT1 t umors (75%), 10 of 13 pT2 tumors (77%), 17 of 19 pT3 tumors (90%), and eigh t of 10 pT4 tumors (80%); overall accuracy was 83%. Overall accuracy of reg ional lymph node involvement, as determined by enhanced MR, was 52%; 24 of 46 node groups were positive. Conclusions: Dynamic and delayed MR imaging can be useful for predicting de pth of cancer invasion, perigastric infiltration (extraserosal invasion), a nd perigastric organ invasion by gastric cancer.