Application Of Optical Coherence Tomography In The Diagnosis Of Colorectal Inflammation And Tumor

OBJECTIVE: To detect colorectitis tissues with different degrees of inflammation using optical coherence tomography(OCT),and quantitatively analyzed the characteristics of submucosal morphological changes in HE image and OCT image,in an attempt to find unique diagnostic indicator parameters to achieve a graded diagnosis of colorectalitis;Meanwhile,to detect colorectal cancer and precancerous lesions tissue using OCT,and explored the diagnostic value of OCT for colorectal cancer and precancerous lesions by analyzing the coincidence rate of them between OCT diagnosis and pathological diagnosis.METHOD:1)Construction of a mouse model of colorectitis and colorectal cancer;2)OCT scan detection and HE pathological staining of colorectal tissues in a mouse model;3)To quantitatively analyze the characteristics of submucosal morphological changes in the HE image and OCT image with different degrees of colorectitis tissues,so as to find the morphological index parameters in HE image and OCT image which can be used to grade the degrees of colorectalitis;4)To analyze the coincidence rate of OCT diagnosis and pathological diagnosis for colorectal cancer and precancerous lesions.RESULT:1)The mouse model of colorectitis and colorectal cancer was successfully constructed.2)The characteristics of submucosal morphological changes in the HE image with different degrees of colorectitis:The correlation coefficient between Angle of duplicature and the degrees of inflammation was 0.853,p<0.01,which was significant correlation;the correlation coefficient between Space between duplicature and the degrees of inflammation was 0.915,p<0.01,which was significant correlation;the correlation coefficient between Submucosal area and the degrees of inflammation was 0.819,p <0.01,which was significant correlation;the correlation coefficient between Submucosal width and degrees of inflammation was 0.451,p<0.01,which was significant correlation;the correlation coefficient between Thickness of muscularis and degrees of inflammation was-0.093,p>0.05,which was no correlation.The angle of duplicature gradually increased with the severity of inflammation,but there was no significant difference in the mean difference between the normal group and the mild group,the moderate group and the severe group(p>0.05);the space between duplicature gradually increased with the severity of inflammation,there was significant difference in the mean difference among the groups(p<0.05);the submucosal area gradually increased with the severity of inflammation,but there was no significant difference in the mean difference between the normal group and the mild group,the mild group and moderate group(p>0.05);the submucosal width was significantly wider in the severe group than in the other groups,and there was significant difference in the mean difference(p<0.05);the thickness of muscularis did not change significantly with degrees of inflammation,and there was no significant difference in the mean difference among the groups(p>0.05).3)The characteristics of submucosal morphological changes in the OCT image with different degrees of colorectitis:The correlation coefficient between Space between duplicature and the degrees of inflammation was 0.800,p<0.01,which was significant correlation;the correlation coefficient between Space between duplicature and the degree of inflammation was 0.648,p<0.01,which was significant correlation.The space between duplicature gradually increased with the severity of inflammation,there was significant difference in the mean difference among groups(p<0.05),excepting between the normal group and the mild group(p>0.05);Submucosal+ muscularis width of the severe group was wider than other group,and there was significant difference in the mean difference between the severe group and other groups(p<0.05).4)The coincidence rate of OCT diagnosis and pathological diagnosis of colorectal cancer and precancerous lesions:The sensitivity,specificity,positive predictive value and negative predictive value of OCT imaging in the diagnosis of colorectal cancer and precancerous lesions were respectively 87.50%,75.00%,82.35%,81.82%.CONCLUSION: As a new type of imaging detection technology,OCT has ultra-high resolution.The morphological features of OCT imaging have a good correlation with HE histopathology,and the pathological changes of mucosa and submucosa can be clearly showed in OCT.Also,OCT scan can grade the diagnosis of the degrees of colorectitis in vitro tissue by quantitatively analyzing the measurement data of OCT.The space between duplicature(?m)and the submucosal+muscularis width(?m)are good diagnostic parameters.Otherwise,the coincidence rate of OCT diagnosis and pathological diagnosis of colorectal cancer and precancerous lesions in vitro tissue was very high,which is of great significance for early colorectal cancer screening and clinical diagnosis and treatment.