Clinical Value Of CT Can Be Used To Evaluate The Pathological Type And Depth Of Invasion Of Gastric

Part1:The application value of The Spectral CT Imaging for Preoperative pathological types of Gastric cancerObjective To explore the value of gemstone spectral imaging(GSI)with single source dual-energy CT in the preoperative assessment the pathological type of gastric cancers.Methods Totally91patients with gastric cancer diagnosed by gastroscopy underwent double-phase enhanced CT scan using single source dual-energy CT by GSI mode from Oct.2012to Dec.2013. Measure the iodine concentration(IC)、water concentration and spectral HU curve of lesions with GSI Viewer in the arterial and venous phase. The spectrum characteristic parameters between different pathological type of gastric cancer were analyzed statistically by One-way analysis of variance, and correlated with postoperative pathologic results.Results91cases of gastric cancer patients,38cases belonged to tubular adenocarcinoma,27cases belonged to signet ring cell carcinoma,16cases belonged to mucous adenocarcinoma. In the arterial phase, The average iodine concentration of tubular adenocarcinoma, signet ring cell carcinoma and mucous adenocarcinoma were (11.57±3.54)×100ug/cm3,(9.53±3.25)×100ug/cm3and (5.31±1.33)×100ug/cm3respectively, There were significant difference in all three types.(P<0.001); In the portal vein phase, The average iodine concentration of tubular adenocarcinoma, signet ring cell carcinoma and mucinous adenocarcinoma respectively were (22.46±8.32)×100ug/cm3、(18.07±1.82)×100ug/cm3、(18.06±2.92)×100ug/cm3, There were statistically significant difference between tubular adenocarcinoma and signet ring cell carcinoma, tubular adenocarcinoma and mucous adenocarcinoma (P<0.001), but There was no significant difference between signet ring cell carcinoma and mucous adenocarcinoma (P=0.99).The Normalized iodine concentration (NIC) performance of similar laws, there was statistically significant difference (P<0.001)between the different pathological type of gastric cancer in the arterial phase, but there was no significant difference between signet ring cell carcinoma and mucous adenocarcinoma (P=0.85). The mean slope rates of spectral HU curve of tubular adenocarcinoma, signet ring cell carcinoma and mucous adenocarcinoma were (-1.36±0.46)、(-1.16±0.39)、(-0.64±0.16) respectively, The mean slope rates of spectral HU curve of the three types were in turn lower, there was statistically significant difference among the three types (P<0.001). In the portal vein phase, There was statistically significant difference between tubular adenocarcinoma and signet ring cell carcinoma, There was statistically significant between tubular adenocarcinoma and mucous adenocarcinoma also (P<0.05); There was no significant difference between signet ring cell carcinoma and mucous adenocarcinoma (P=0.86).Conclusion Spectral CT can be used for preoperative evaluation on the different pathological type of gastric cancer. Part2:The application value of The Spectral CT Imaging for Preoperative T Staging of Gastric cancerPurpose To evaluate the clinical utility of gemstone spectral imaging (GSI) in the diagnosis and preoperative T staging of the gastric carcinoma.Methods Totally91patients with gastric cancer diagnosed by gastroscopy underwent double-phase enhanced CT scan using single source dual-energy CT by GSI mode from Oct.2012to Dec.2013. In order to make sure for the double-blinded nature of the study, divided the radiologists into two groups, Group A reviewed all the kVp images (cross section and multi-planer reconstruction, MPR) for T staging. Group B reviewed all the iodine-water based material-decomposition images, and the optimal monochromatic images with GSI Viewer software for T staging. Comparing with postoperative pathologic results, and calculated the accuracy of T staging with the two groups. The difference between the two imaging methods was examined by Chi-square test.Results The mean optimal keV for displaying gastric cancer in our patient population was53±6keV in arterial phase and58±8keV in portal venous phase. Compared to the histopathologic staging, the overall accuracies for T staging were61.5%(56/91) and76.9%(70/91, respectively in group A and B. The accuracy of CT for tumor staging with kVp images was91.2%(83/91) for T1,78.0%(70/91)for T2,73.6%(67/91) for T3, and80.2%(73/91)for T4tumors. These values with the optimal monochromatic keV images and iodine-water based material-decomposition images were94.5%(86/91)for T1,84.6%(77/91)for T2,83.5%(76/91) for T3, and91.2%(83/91) for T4tumors. Chi-square test revealed there was significant difference between the overall accuracies for T staging (P=0.036), but there were no significant difference between the accuracies for T1-T4(P>0.05).Conclusion Compared with the kVp image, the accuracy of gemstone spectral imaging in the evaluation of preoperative T staging of gastric cancer is higher. GSI could be useful in identifying the infiltration depth of gastric cancer, has important clinical value.