Song Liu, Presenter: Nothing to Disclose

Jian He MD, PhD, Abstract Co-Author: Nothing to Disclose

Wenxian Guan, Abstract Co-Author: Nothing to Disclose

Qiang Li, Abstract Co-Author: Nothing to Disclose

Haiping Yu, Abstract Co-Author: Nothing to Disclose

Zhuping Zhou, Abstract Co-Author: Nothing to Disclose

Shanhua Bao, Abstract Co-Author: Nothing to Disclose

Zhengyang Zhou, Abstract Co-Author: Nothing to Disclose

The objective of this study was to confirm whether diffusion-weighted (DW) magnetic resonance (MR) imaging has some added value to T2-weighted (T2W) and dynamic contrast-enhanced (CE) MR imaging in T staging of gastric cancer on 3 T MR scanners.

Fifty-one patients (age range, 28-82 years; mean, 62 years; 33 men and 18 women) with a total of 51 gastric cancers underwent axial T2W, dynamic CE and DW (b, 0 and 1000 s/mm²) MR imaging. Two radiologists independently interpreted the images for T staging of the tumors. The tumors were staged based on the histopathological findings that assign the tumor stage according to TNM classification of American Joint Committee on Cancer (AJCC, 7th edition). McNemar test was used to check the differences among three MR image sets (T2W+CE, T2W+DW, T2W+CE+DW) in the diagnostic accuracy with the reference of post-operative histopathological results. Inter-observer agreement was calculated by using kappa statistics.

The overall accuracy of T staging in pT1-4 gastric cancers by T2W+CE+DW (88.2%) was significantly higher than that by T2W+CE and T2W+DW (both 76.5%, P=0.031). For advanced lesions (pT2-4), T staging accuracy by T2W+CE+DW (92.3%) was significantly higher than that by T2W+CE (76.9%, P=0.031). There were no significant differences of T staging accuracy in pT1-4 and pT2-4 gastric cancers between T2W+CE and T2W+DW (P=1.000, 0.125). Kappa values in inter-observer agreement test were 0.855, 0.826 and 0.578 in T2W+DW, T2W+CE+DW and T2W+CE.

DW adds useful information to T2W and CE MR imaging in T staging of gastric cancer, especially in advanced lesions. 

DW can be routinely added into MR imaging for preoperative T staging of gastric cancer without much time consuming. In patients who fail to fulfill CE imaging, DW may replace CE to ensure successful MR examinations.

Liu, S, He, J, Guan, W, Li, Q, Yu, H, Zhou, Z, Bao, S, Zhou, Z, Added Value of Diffusion-weighted MR Imaging to T2-weighted and Dynamic Contrast-enhanced MR Imaging in T Staging of Gastric Cancer.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045470.html