Study On Applicating Induced Fluorescence Imaging For Sarcoma Localization In Vivo

[Objective]The thesis studied near ultraviolet-induced fluorescence imaging for localization of carcinoma in order to offer real time carcinoma detection for tumorectomy or photodynamic therapy and so on. Meanwhile this method plays a very important role for early period diagnosis of cancer and improves the detection rate for tumor biopsy.This research also draws assistance from medical image process technology to calibrate and evaluate the image of near ultraviolet light induced fluorescence: The calibration for fluorescence marked points and actual positions of cancer makes this mythology more feasible and accuracy.[Methods]Near ultraviolet was adopted to induce the fluorescence of the photosensitizer concentrated in the Sarcoma. By choosing wavelength between 395-425 nm and power density in the irradiated area (120 mW/cm~2) of emission light, the fluorescence image was collected through self-designed imaging collecting system. The effect of Hematoporphyrin Derivative(HpD) dose and image collection time upon the diagnosis accurate rate were studied and optimized.The fluorescence image was processed and analyzed by extracting borderline of carcinomaand compared with histology biopsy to determine the feasibility and accuracy of this method.[Results]1. Through the experiments at different doses of HpD, 60 mg/Kg was shown to be the best dose at 18 hours. Lower and higher dose groups give somehow false negative and false positive diagnosis.2. Through the experiments at different collection time of fluorescence image, the best fluorescence image was taken at 18 hours with the photosensitizer dose of 60 mg/Kg. 3. The curve of gray value shows that the fluorescence intensity of S180 Sarcoma in rat was the strongest at 10 hours, however, the contrast of carcinoma image was the best at 18 hous. After normalization of cancer fluorescence image, the approximate gray value on the borderline of carcinoma could give important parameters for detecting and extracting borderline of carcinoma.[Conclusions]1. The fluorescence intensity of S180 carcinoma is proportional to the dose of photosensitizer and increases first and decreases later with the collection time. However, the diagnosis accuracy of high and low dose groups is relatively lower. The appropriate dose and image collection time could be selected in order to get the best fluorescence image with the accurate localization and borderline of carcinoma.2. The tissue optics was combined with medical image processing. The relatively objective and accurate evaluation to the tumor fluorescence image was obtained. The estimated parameters make this method feasible on real time monitor during tumorectomy and early detection of carcinoma and so on.