Application Of Perfusion Combine With Contrast-Enhanced Examination In Reproducibility Of Region Of Interests And In Evaluation Of Variously Differentiated Gastric Adenocarcinoma

Part one Application of CT perfusion combined contrast-enhanced examination in reproducibility of region of interestsObjective:To determine the consistency and reproducibility of one-step perfusion and contrast-enhanced CT parameters in gastric cancer using different region of interests(ROIs).Materials and Methods:From September 2016 to December 2016,30 patients with gastric cancer confirmed by surgical pathology underwent preoperative one-step CT scan in Revolution CT that contain the plain scan,perfusion and two phase contrast-enhanced CT scan.All the measurements were performed on the CT perfusion 4D software(body tumor software)on the workstation of ADW4.6.The CT values(HU)and different perfusion parameters of gastric cancer lesions were measured using two different ROI protocols: circular ROI in the tumor enhanced obviously and the freehand outline ROI.All the data were measured and analyzed by two radiologists(A and B),and radiologist A remeasured all the data two months later.The intra-and inter-observer consistency and reproducibility use interclass correlation coefficient(ICC).The two protocols parameters were compared in the paired sample T test or Wilcoxon signed rank test.Results:All the ICC in the intra-observer obtained by freehand outline ROI were excellent(all ICC>0.80),while the ICC of MTT value obtained by circular ROI were good,the ICC of other parameters were excellent.All the ICC in the inter-observer obtained by freehand outline ROI were excellent(all ICC>0.80),while all the ICC by circular ROI were good(ICC 0.60-0.80).There were significant differences between the value of the TTP,PEI,MSI,BV and the CT values in the plain,arterial and venous phase in two different ROI protocols(P<0.05).Conclusion:1.The parameters analysis by freehand outline ROI protocol can improves intraand inter-observer consistency and reproducibility.2.There were significant differences between the value of the TTP,PEI,MSI,BV and the CT values in the plain,arterial and venous phase in two different ROI protocols,and no statistically significant difference between BF,MTT,Tmax and PS value.Part two Application of one-step examination in reproducibility of region of interestsObjective:To explore the diagnostic value of one-step perfusion and contrast-enhanced CT imaging in the quantitative evaluation of different degree of tumor cells of gastric cancer.Materials and Methods:From September 2016 to October 2017,90 patients with gastric cancer confirmed by surgical pathology underwent preoperative one-step CT scan in Revolution CT that contain the plain scan,perfusion and two phase contrast-enhanced CT scan.All the measurements were performed on the CT perfusion 4D software(body tumor software)on the workstation of ADW4.6.All the CT values(HU)were measured using circular ROI and different perfusion parameters of gastric cancer lesions were measured using the freehand outline ROI.Independent samples t test and analysis of variance(ANOVA)were respectively used to analyze the relationship between the perfusion parameters and patients age,gender and different location.The perfusion parameters of different degree of tumor cells of gastric cancer were compared with independent samples t test.Receiver operating characteristic(ROC)was used to determine the diagnostic efficiency of the corresponding parameters.Results:There were 90 patients with gastric cancer,including mucinous carcinoma in 7cases,mixed adenocarcinoma in 5 cases,and non-mucinous adenocarcinoma in 78cases(well-differentiated,moderately-differentiated and poorly-differentiated adenocarcinoma were 7,27 and 44 cases respectively).The Lauren type,lymph nodes metastases and nerve or vascular invasion in patients are related to the different degrees of differentiation of gastric adenocarcinoma.The intestinal-type gastric cancer in differentiated group more than the poor differentiated group,the diffuse-type less than the poorly-differentiated group,while the mixed-type have no significant difference in the two group.In differentiated group the patients don't have nerve and vascular invasion more than the poorly-differentiated group,patients have nerve and vascular invasion less than the poorly-differentiated group.The perfusion parameters have no significant difference in different group of age,gender and location.The PS value of the poorly-differentiated group was higher than those of the differentiated group(P < 0.01),the other perfusion parameters have no significant difference.Conclusion:1.PS values,which is helpful to distinguish the poorly-differentiated group from differentiated group,is the most important perfusion parameters.2.The Lauren type,lymph nodes metastases and nerve or vascular invasion in patients are related to the different degrees of differentiation of gastric adenocarcinoma.