The Study Of The Differential Diagnosis Value Of Dual-energy CT In Mass Type Colorectal Adenocarcinoma And Benign Occupying Lesion

Part Ⅰ Parameter characteristics of dual-energy CT of normal large intestine wall Objective: To investigate the Dual-energy CT parameters of iodine concentration and the characteristics of standardized iodine concentration in normal intestine wall.Materials and Methods: Total abdominal dual-energy CT scans were performed in our hospital from October 2018 to April 2022,and 30 cases without inflammatory lesions of the large intestine(confirmed by colonoscopy)were collected.The iodine concentration and standardized iodine concentration of ascending colon,transverse colon,descending colon,sigmoid colon and rectum were measured in arterial phase,venous phase and delayed phase of enhanced scanning on dual-energy iodine map.The 30 cases were divided into three groups according to age: group A was 20-40 years old,group B was 40-60 years old,and group C was over 65 years old.One-way analysis of variance(ANOVA)was used to compare the iodine concentration values and standardized iodine concentration values of ascending colon,transverse colon,descending colon,sigmoid colon and rectum in each stage of enhanced scanning.Similarly,analysis of variance(ANOVA)was used to compare the differences among three different age groups A,B and C.Results: There was no significant difference in iodine concentration and standardized iodine concentration in ascending colon,transverse colon,descending colon,sigmoid colon and rectum during arterial phase,venous phase and delayed phase.As well,there was no significant difference in iodine concentration and standardized iodine concentration in ascending colon,transverse colon,descending colon,sigmoid colon and rectum in arterial phase,venous phase and delayed phase in three different age groups A,B and C.Conclusion:There is no significant difference in iodine concentration and standardized iodine concentration in ascending colon,transverse colon,descending colon,sigmoid colon and rectum.There is also no significant difference in iodine concentration and standardized iodine concentration in different parts of the colon wall in different age groups.Part Ⅱ Value of dual energy CT in the differential diagnosis of mass adenocarcinoma and benign occupying lesions in the large intestineObjective: To investigate the value of Dual-energy CT imaging in differential diagnosis of large intestine mass adenocarcinoma and benign occupying lesions.Materials and Methods: From October 2018 to April 2022,40 cases of colorectal mass adenocarcinoma and 30 cases of benign occupying lesions confirmed by colonoscopy or surgical pathology were collected,including 70 cases in total.Using retrospective analysis,record the mass type adenocarcinoma and benign occupying lesions in the arterial and venous phase and delayed phase of iodine concentration(IC),standardized iodine concentration(NIC),mixed energy CT value,conventional CT and conventional CT signs,adopt the corresponding statistical method,comparing the difference between the two,and the difference was statistically significant indicators do ROC curve analysis and multivariate Logistic regression analysis to investigate its diagnostic efficiency.Results: The IC,NIC and mixed-energy CT values of mass adenocarcinoma in arterial phase and delayed phase were higher than those of benign occupying lesions,and the differences were statistically significant(P<0.05),and there was no significant difference in these three indexes in venous phase.There was no significant difference in the conventional CT values in the three phases.There was no significant difference in the morphology,margin,density,longest diameter of the lesion and the thickening of the adjacent intestinal wall.However,there were significant differences in the enhancement mode,the invasion of peripheral mesenteric fat by CT and peripheral mesenteric lymph node metastasis.ROC curve showed that the diagnostic efficiency of NIC in arterial phase was greater,AUC and Youden index were 0.917 and 0.742,respectively.The multivariate Logistic regression results of age,sex,family history,inflammatory bowel disease,tumor index CEA,iodine concentration and standardized iodine concentration showed that standardized iodine concentration was statistically significant,and the model had high predictive value.Conclusion: Dual-energy CT is superior to conventional CT in the differential diagnosis of large colon mass adenocarcinoma and benign space-occupying lesions,and the value of NIC in arterial phase is the greatest.