Song Liu, Presenter: Nothing to Disclose

Liang Pan, Abstract Co-Author: Nothing to Disclose

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

Ping Cao, Abstract Co-Author: Nothing to Disclose

Zhengyang Zhou, Abstract Co-Author: Nothing to Disclose

 The objective of this study was to evaluate the application of CT spectral imaging in preoperative T staging of gastric cancer.

Fifty-two patients with gastroscopically confirmed gastric cancer were included prospectively and underwent preoperative multiphase-enhanced CT scans. Spectral imaging was performed in the arterial phase, automatic tube current modulation was adopted in the portal venous and delayed phases. Regions of interest (ROIs) were placed within the tumor, stomach wall, peripheral and distant fat to determine the optimal monochromatic image with the highest contrast-noise-ratio (CNR) between the cancer and surrounding tissues. Spectral curves of those ROIs were obtained. Two radiologists interpreted polychromatic and optimal monochromatic images of 52 patients and assessed T staging independently. With the reference of postoperative histopathological findings, T staging accuracy were compared between poly- and monochromatic images. Inter-observer agreement was calculated by kappa statistics.

Preoperative T staging accuracy of gastric cancer by spectral imaging (82.69%, 43/52) was significantly higher than that of polychromatic CT images (71.15%, 37/52)(P =0.031). In terms of each T stage, diagnostic accuracy of spectral imaging was slightly better in T1/3 stages and identical in T2/4 stages compared with that of polychromatic images. Inter-observer agreement (Kappa value) was improved from 0.562 (polychromatic images) to 0.768 (spectral imaging).

CT spectral imaging generating optimal monochromatic images with highest CNR and spectral curves of the tissues, can improve preoperative T staging accuracy of gastric cancer.

CT spectral imaging can replace traditional CT scan in preoperative T staging of gastric cancer with higher diagnostic accuracy without more radiation dose.

Liu, S, Pan, L, He, J, Cao, P, Zhou, Z, Application of CT Spectral Imaging in Preoperative T Staging of Gastric Cancer.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14005313.html