人肺组织氪离子激光—荧光比率探测方法的研究

Improvement of Ratio Detection Technique Using Krypton Ion Laser fluorescence for Lung Tissue

激光—荧光比率探测方法是近几年研究人肺组织肿瘤诊断和定位的新方法。但在临床应用中却发现比率显示的不稳定现象和很大的背景噪声容易造成肿瘤诊断的假阳性误诊。为了探讨产生这种现象的原因，我们使用氪离子激光器和比率探测设备，以提取的离体人肺组织为材料，研究在氪离子激光激发下，组织表面漫反射光和组织内部自体荧光的变化规律和背景噪声产生的原因。在此基础上，研制出采用组织绿色自体荧光代替组织表面反射光，作为参比光的比率探测方法。这种新的比率探测系统具有低的背景噪声，在临床应用中能有效地防止肿瘤诊断和定位中的假阳性误诊。

A new approach for lung cancer detection and localization by ratio fluorometry has been developed in recent years. However, in the clinical application, the phenomena of unsteady ratio display and poor signal to noise ratio were found which may cause a false positive result of tumor diagnosis. In order to explore the reasons for producing the above mentional phenomena, we simulated fluorescence bronchoscope examination in samples of human lung tissue using krypton ion laser as light source and a ratio fluorometer. We made experiments to study the variation regularity between the reflected light and autofluorescence of the tissue and the factors producing background noise of lung tissue ex vitro. Based on these experiments, we presented our new method of ratio detection using the green autofluorescence instead of the reflected light of tissue as reference light for the ratio calculation. The new system of ratio detection showed clear advantage of low background noise. Thus it may effectively prevent false positive results in cancer diagnosis and localization in clinic practice.