A Clinical Study On Ct Enhancement Degree Of Rectal Cancer To Evaluate Diagnostic Efficacy Of Serous Membrane Invasion

Objective:1.To explore the diagnostic value of dual-phase enhancement values of multi-slice spiral CT in judging serous membrane infiltration of rectal cancer.2.To explore the relationship between the enhancement values and imaging signs of CT and the result of pathology and immunohistochemistry in rectal cancer.Methods:Fifty-three patients with rectal cancer underwent multi-slice spiral CT enhanced scan and confirmed by pathology were retrospectively collected.According to the results of postoperative pathology,among them 38 cases were those with serosal invasion with only 15 cases with uninfiltrated serous membrane.All images were transmitted to PACS system.We adopt manual method to measure and calculate the CT enhancement value of perienteric adipose tissue in the arterial and venous phase.The CT enhancement values of the two groups in the arterial and venous phase were statistically analyzed,and the receiver operating characteristic curve was used to evaluate CT enhancement values to confirm the diagnostic ability of serous membrane infiltration in rectal cancer,so as to obtain the diagnostic threshold,accuracy rate,sensitivity and specificity of dual-phase CT enhancement values respectively.The correlation between CT enhancement value of rectal cancer and the result of pathology and immunohistochemistry was analyzed by independent-samples T test,the mean of multiple levels in the group was compared by ANOVA,and the pairwise comparison was performed by LSD test.The relationship between CT signs and the result of pathology and immunohistochemistry was analyzed by chi-square or continuously corrected chi-square test.Results:The difference in terms of dual-phase CT enhancement values of perienteric adipose tissue between the serous infiltrated group and the group that serous membrane was not infiltrated was statistically significant(P <0.001).The area under the curve of CT enhancement values in arterial and venous stages judging serous infiltration of rectal tumor was 0.925 and 0.898,respectively;the diagnostic thresholds were 10.5HU and9.5HU,respectively;the accuracy rate,sensitivity and specificity of diagnosis were arterial phase 79.2%,76.2% and 86.7%;venous stage 81.1%,83.3% and 73.3%.According to different CT imaging signs,the accuracy rate,sensitivity and specificity ofjudging whether serous membrane is invaded were: Serous membrane rough sign 64.2%,71.1% and 46.7%;Fuzzy appearance of fat space around serous membrane 47.2%,39.4% and 66.7%;Extramural tuberous extrinsic sign 50.9%,42.1% and 73.3%.The arterial CT enhancement value of the S-100 positive group(16.94±7.42HU)was higher than that of the negative group(11.19±7.32HU);The arterial CT enhancement value of the nerve invasion group(17.44±6.42HU)was higher than group that nerve was not infiltrated(10.38±7.52HU);And the venous CT enhancement value of the intermediate differentiation group(17.19±8.62HU)was higher than that of the middle-low differentiation group(9.47±5.54HU);All of which were statistically significant(P<0.05).Conclusion:1.The measurement of CT enhancement value in the arterial and venous stages is of certain diagnostic value in judging serous membrane infiltration of rectal cancer,and the diagnostic accuracy rate,sensitivity and specificity are all higher than that of all CT imaging signs.2.Arterial CT enhancement value can be used to evaluate the expression of S-100 and invasion of neural tissue preliminarily.3.patients with nodular outward appearance from MSCT are more likely to have lymph node metastasis in the mesorectum.