【摘要】 在药物荧光成像系统中较好的荧光像的信噪比和分辨本领,可最大限度地克服肿瘤诊断中出现的假阳性,降低误诊率。理论分析并近似计算了用蓝光作为诊断早期鼻咽癌的激发光源时,信号和背景光的亮度分别为4.5×10-2lm.m-2.sr-1和877 lm.m-2.sr-1。结果表明,为了能从背景中分辨出信号,窄带栅滤光片的荧光透过率应尽可能大,而背景光要截止到原来的4.3×10-5的量级。根据有色玻璃的吸收特性,实验时适当增加光在玻璃中的行程和带宽,使信号和背景光的透过率之比增大,从而得到较好的荧光像的信噪比和分辨本领,提高了图像目视探测的灵敏度。更多还原

【Abstract】 The quantity value of signal and background light of fluorescence imaging system of nasopharyngeal carcinoma is calculated when photosensitizer is excited by the light at the wavelength of 488nm.In order to distinguish the signal from the background light,the light-transmission coefficient of a narrow-band filter must be as great as possible and noise must be reduced by a factor of 4.3×10^-5.According to the absorption characteristic of colored glass,the ratio of signal transmission coefficient to background light transmission becomes large with optical-path increased suitably.If the thickness of the colored glass and the band width of the narrow-band filter now on hand is encreased properly,fine signal-to-noise ratio and resolving capability of fluorescence imaging can be obtained.更多还原