Extraserosal invasion in advanced gastric cancer: evaluation with MR imaging.

PURPOSE

To evaluate the usefulness of magnetic resonance (MR) imaging in the diagnosis of extraserosal invasion in advanced gastric cancer.

MATERIALS AND METHODS

MR imaging was performed in 48 patients with advanced gastric cancer, and the results were correlated with the histopathologic findings. Images perpendicular to the gastric wall with cancer were obtained with spoiled gradient-recalled acquisition in the steady state (GRASS). The degree of serosal invasion was classified on the basis of the appearance of a low-signal-intensity band around the lesion.

RESULTS

Advanced gastric cancer appeared as a thickened wall of high signal intensity after the administration of contrast material. A low-signal-intensity band disappeared or showed irregularity in the area of extraserosal invasion by the gastric cancer. The MR imaging-determined grade correlated with the histopathologic findings for 11 of 14 (79%) pT2 tumors, 23 of 24 (96%) pT3 tumors, and eight of 10 (80%) pT4 tumors. The overall accuracy was 88%.

CONCLUSION

Presence of a low-signal-intensity band at MR imaging is useful for the preoperative evaluation of serosal invasion.