A Preliminary Research On The Clinical Value Of Spectral CT Imaging In Evaluating The Pathological Type Of Gastric Cancer

Objective：To study preliminarily the clinical application of spectral CT imaging in evaluation thepathological classification and different differentiation-state of gastric cancer before surgery.Materials and Methods:118cases of patients suspected of gastric cancers by gastroscopy wereunderwent triple-phase enhanced CT scan using single source dual-energy CT on gemstone spectralimaging （GSI） mode. All data were transmitted to AW4.4workstation to obtain the iodineconcentration(IC)、water concentration and spectral HU curve of lesions with GSI Viewer. Normalizediodine concentration (NIC) was obtained by dividing the iodine concentration of tumor to that of aortaand the slope of HU curve (ΔCT value between50keV and100keV divided by50) was calculated.According to pathologic results, all study objects were divided into67non-mucinous gastric carcinoma(non-MUC) and24mucinous carcinoma (MUC),then MUC were divided into mucinousadenocarcinoma (8cases) and signet ring cell carcinoma (16cases); non-MUC were divided into well/moderate differentiated group (32cases) and poor differentiated group (35cases). Parameters of iodineconcentration、water concentration、NIC and the slope of spectral HU curve were analyzed statisticallyand results were correlated with the pathological findings.Results:1.Comparison between non-MUC and MUC showed that: The material-based concentration ofnon-MUC was much higher and the spectral HU curve was much abrupt than those of MUC,and theIC、NIC、absolute mean slope rates of the former were higher than those of the latter,significantdifference (all of them P<0.05) were all found both in venous phase(VP)and parenchymalphase(PP).The water concentration of the non-MUC were all higher than those of MUC in AP,VP andPP, but no significant difference (all of them P>0.05) was seen in all three phases.2.In MUC group, the further comparison between signet ring cell carcinoma and mucinousadenocarcinoma showed that: The material-based concentration of signet ring cell carcinoma was much higher and the spectral HU curve was much abrupt than those of mucinous adenocarcinoma,and the IC、NIC、absolute mean slope rates of the former were higher than those of the latter,significant difference(all of them P<0.05) were all found both in venous phase(VP)and parenchymal phase(PP).The waterconcentration of the signet ring cell carcinoma was lower in AP, and higher both in VP and PP, but nosignificant difference (all of them P>0.05) was seen in all three phases.3. In non-MUC group, the further comparison between the well/moderate differentiated and poordifferentiated adenocarcinoma showed that: The material-based concentration of the poor differentiatedwas much higher and the spectral HU curve was much abrupt than those of the well/moderatedifferentiated adenocarcinoma, and the IC、NIC、absolute mean slope rates of the former were higherthan those of the latter,significant difference (all of them P<0.05) were all found both in venousphase(VP)and parenchymal phase(PP).The water concentration of the poor differentiatedadenocarcinoma was higher in AP, and lower both in VP and PP, but no significant difference (all ofthem P>0.05) was seen in all three phases.Conclusions: Spectral CT imaging is a new mode with multi-parameter and quantitative analysisfunction in which many parameters were showed significant differences between different pathologicaltypes of gastric cancer. To some extent, Spectral CT can reflect the pathological and histochemicalcharacteristics of gastric cancer, evaluate the differentiation-state of the tumor cells and play animportant role in guiding the treatment and prognosis of gastric carcinoma.