Nonlinear Optical Imaging Of Intestinal Microstructures Based On Second Harmonic Generation And Two-Photon Excited Fluorescence

Adenomatous polyps are polyps that begin on the lining of the colon and which carry a high risk of cancer. Early detection of the malignant transformation of Adenomatous polyp is an effective way to improve the prognosis of colorectal cancer. Early lesions of the bowel tissue commonly occur in mucosa. The variation on the morphology and distribution of the main components in mucosa is very relevant to the pathology in intestinal system. Hence, the microstructure imaging of the mucosa plays an important role to diagnose ealy bowel cancer detection and prevention. Recently, Multiphoton microscopic imaging technology which is a nonlinear optical imaging technology, based on two-photon excited fluorescence and second harmonic generation, has the ability to imaging microstructures of the tissue. This technology has emerged to a feasible and promising approach for diagnosis of early gastrointestinal cancer, moreover, this issue has been becoming a hot topic in the field of biomedical photoncis. In this paper, firstly, Multichannel mode of multiphoton microscopic imaging technology was used to observe the microstructures of the mucosa in fresh, unfixed, and unstained intestinal tissue. The microstructures of the main components in mucosa layer such as columnar cells, goblet cells, intestinal glands were clearly observed in MPM images. The features are well consistent with the H&E stained image. Our results demonstrated that Multiphoton microscopic imaging technology can present the microstructures of intestinal tissue at the cellular and subcellular level. Then, we applied multiphoton microscope to observe the morphology of human normal colonic mucosa, tubular adenoma and sessile serrated adenoma. We compare these features to the H&E stained images, the results coincide well. Our findings show that multiphoton microscopic imaging has the comparable resolution with pathology and can quantitatively analyze the microstructure change of intestinal tissue in carcinogenesis. In a word, our findingd suggested that Multiphoton microscopic imaging technology based on nonlinear optical effects has great potential for providing more accurate and comprehensive information in physiological diagnosis of intestinal tissue. With the advent of the multiphoton endoscopy, Multiphoton microscopic imaging technology may be used for in vivo diagnosis and monitoring of the status of intestinal disease in the near future.