Chaudhry H W, Richards-Kortum R, Kolubayev T, Kittrell C, Partovi F, Kramer J R, Feld M S
George R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge 02139.
Lasers Surg Med. 1989;9(6):572-80. doi: 10.1002/lsm.1900090606.
Fluorescence spectroscopy is a promising new technique for discrimination of normal and atherosclerotic arterial tissues. It has been suggested that this technique be used as a guidance system for laser angiosurgery catheters; however, irradiation by 476-nm light can change the spectroscopic properties of arterial tissue. We present studies that establish intensity levels and exposure times at which alterations in tissue spectral properties are minimal. We also investigate the nature of spectral alterations following exposure of normal human aorta to high intensities of 476-nm laser light. Changes in laser-induced fluorescence (LIF) are characterized by two prominent features: the peak fluorescence intensity decreases permanently, and the fluorescence lineshape changes in a largely reversible way. We relate these changes to alterations in individual tissue chromophores: permanent changes in absolute fluorescence intensity are due to irreversible changes in tissue fluorophores, reversible changes in fluorescence lineshape are due alterations in tissue absorbers. A simple kinetic model is used to describe the decrease in absolute fluorescence intensity.
荧光光谱法是一种用于区分正常动脉组织和动脉粥样硬化组织的很有前景的新技术。有人建议将该技术用作激光血管手术导管的引导系统；然而，476纳米光的照射会改变动脉组织的光谱特性。我们进行了研究，确定了组织光谱特性变化最小的强度水平和暴露时间。我们还研究了正常人主动脉暴露于高强度476纳米激光后光谱变化的性质。激光诱导荧光（LIF）的变化有两个突出特点：峰值荧光强度永久性降低，荧光线形在很大程度上以可逆方式变化。我们将这些变化与单个组织发色团的改变联系起来：绝对荧光强度的永久性变化是由于组织荧光团的不可逆变化，荧光线形的可逆变化是由于组织吸收体的改变。一个简单的动力学模型被用来描述绝对荧光强度的降低。
