Monte Carlo modeling was developed for simulating the light induced autofluorescence spectra of colon and cervical tissues at different dysplasia grades.These tissues were frozen sliced into 100 um thickness. The transmittance (Ta) and backscatter spectra (Ra) of these tissues were measured using double integral sphere system. The scattering coefficient, µ s, and absorption coefficient, µ a, were determined by the inverse adding-doubling (IAD) method from the Ta and Ra. spectra. The fluorescence intensity and spectra of these sliced tissues were measured using spectrometer system with cooled 2D CCD array. We simulated light energy distribution in tissue at 330 nm excitation and then convolution with fluorophores intensity and escape function in each tissue layer. The results of the simulation show:(1)fluorescence spectra change with different tissue characteristics, (2)fluorescence intensity decrease with the development of the dyplasia grades and the mucosa thickness, (3)the relative collagen signal decreases, hemoglobin signal increases, and NADH signal increases along with the dyplasia development. The simulated results matched well in vivo measured results. The approach provides an important means for understanding tissue fluorescence spectra's changes that are very critical for clinic diagnosis.
Cervical cancer is the top rank of the common malignant tumors among women in Taiwan. In all of the universal diagnosis, Pap smear is the most convenient but has higher false negative. Although Colposcopy has higher accuracy, it can 1 detect lesions at the endocervix tissue. Autofluorescence diagnosis is characterized by the stimulation of endogenous fluorophores, such as. collage, NADH, and FAD in normal and abnormal tissue. It is minimum invasion and real time. I n this research, we developed a small autofluorescence spectra measurement system. It consists of o sensitive PMT with a double gratings spectrometer; a Y typefiber including /&excitation to IPemissionfibers. and xenon lamp with monochromate as multi-wavelength light source. We utilized this autofluorescence spectra and excitation-emission matrices (EEM) in cervical cancer study and measured normal and abnormal tissues (cervical intraepithelial neoplasia, ClN squamous cell carcinoma:SCC). EEM represented multi-excited wavelength induced dfferenf range wavelength af the emission. It let us get more information about tissues 'characteristic. We usedpartial least squares (PLS) to analyze these data of the spectra and EEM, The result shows diagnostic abilify by autofluorescence fechnology can apply to ClN and using PLS analyzedpathological changes of the cervical tissue has discriminative. We also got high
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.