Preoperative T Staging of Gastric Cancer: Comparison of Diffusion- and T2-Weighted Magnetic Resonance Imaging

Objective: The objective of our study was to assess the clinical feasibility of diffusion-weighted (DW) magnetic resonance (MR) imaging in preoperative T staging of gastric cancer prospectively. Methods: Forty-five patients underwent axial T2-weighted (T2W) and DW (b, 0 and 1000 seconds/mm(2)) MR imaging. Two radiologists interpreted the images for detection and staging of the tumors independently. The McNemar test was used to check differences in diagnostic accuracy with the reference of postoperative histopathological results. Results: Diffusion-weighted and T2W images detected 44 and 42 of 45 histologically confirmed lesions, respectively. Furthermore, DW images detected 11 of 12 pT1 lesions compared to 9 of 12 lesions by T2W images. The staging accuracy of advanced gastric cancer (>= pT2) in DW imaging is significantly higher than that in T2W imaging (87.9% and 69.7%, respectively; P < 0.05). Conclusions: Diffusion-weighted is superior to T2W imaging in detection of early gastric cancers (pT1) and staging advanced cancers (>= pT2).