Detection of lymph-node metastases in patients with gastric carcinoma: comparison of three MR imaging pulse sequences

Background: To compare the diagnostic accuracy of magnetic resonance (MR) i mages obtained with three different pulse sequences for lymph-node metastas es in patients with gastric cancer. Methods: T1-weighted spin-echo (SE), breath-hold T2-weighted fast SE, and t riphasic gadolinium-enhanced dynamic gradient-recall-echo (GRE) MR images o btained in 16 patients with gastric carcinoma were retrospectively reviewed . Regional lymph nodes were assigned to four different groups, and image re view was conducted on a lymph-node group-by-group basis; 64 lymph-node grou ps were reviewed by two radiologists. Relative sensitivity, specificity, an d accuracy were determined based on the findings with definitive surgery an d follow-up imaging. Diagnostic accuracy was determined by means of receive r-operating-characteristic (ROC) analysis. Results: Relative sensitivities for lymph-node metastases with T1-weighted SE, breath-hold T2-weighted fast SE, and dynamic GRE images were 61%, 94%, and 59%, respectively. Relative sensitivity with breath-hold T2-weighted fa st SE images was significantly greater than that with T1-weighted SE (p < 0 .05) and dynamic GRE (p < 0.05) images. Diagnostic accuracy determined by R OC analysis was marginally higher with breath-hold T2-weighted fast SE (are a under ROC curve [Az] = 0.87) than with T1-weighted SE (Az = 0.78, p = 0.0 8) and dynamic GRE (Az = 0.79, p = 0.12) images. Conclusion: Breath-hold T2-weighted fast SE sequence is useful in the detec tion of regional lymph-node metastases in patients with gastric carcinoma.