Comparing MR imaging and CT in the staging of gastric carcinoma

OBJECTIVE. The purpose of this study was to assess the usefulness of breath -hold two-dimensional (2D) fast low-angle shot (FLASH) and T2-weighted turb o spin-echo fast MR imaging compared with helical CT in the staging of gast ric carcinoma. SUBJECTS AND METHODS. Thirty patients with gastric carcinoma underwent pre operative MR imaging and helical CT. MR imaging at 1.5 T was performed imme diately after the intramuscular injection of scopolamine and the oral admin istration of water or effervescent granules. Breath-hold 2D FLASH T1-weight ed images in all three planes, turbo spin-echo T2-weighted axial images, an d gadolinium-enhanced fat-suppressed 2D FLASH axial images were included. H elical CT was performed 60 sec after initiation of IV contrast medium injec tion (2.5-3 ml/sec). Two groups of two radiologists each independently anal yzed the MR and helical CT findings, and these results were compared with t he pathologic findings. RESULTS. For T staging, MR imaging accuracy was higher than that of helical CT (73.3% and 66.7%, respectively); however, the accuracies of the two met hods were not significantly different from each other (McNemar test, p > 0. 05). Overstaging was noted in 6.7% of cases with MR imaging and 10% with he lical CT. Understaging was noted in 20% of cases with MR imaging and 23.3% with helical CT. For N staging, the accuracies of MR imaging and helical CT were 55% and 58.6%, respectively, with no statistical significance (overst aging, 10% and 6.9%; understaging, 34.5% and 34.5%, respectively). CONCLUSION. MR imaging was comparable to helical CT in the T and N staging of gastric cancer.