吲哚菁绿对大鼠脑皮层血管近红外光学特性及光学相干层析成像的影响

Effects of Indocyanine Green on Near-Infrared Optical Properties and Optical Coherence Tomographic Image of Cerebral Blood Vessel in Vivo in Rats

研究观察了吲哚菁绿(ICG)对大鼠脑皮层血管近红外光谱学特性及光学相干层析成像(OCT)的影响。实验中,将SD大鼠颞部开颅,暴露并标记大脑中动脉,给予动物尾静脉注射ICG溶液,应用可见-近红外反射光谱仪和OCT系统检测脑皮层血管反射光谱的动态变化和衰减系数的特征性变化。结果显示,ICG注射后,大脑中动脉的反射光谱在ICG的吸收峰(800nm)左右出现一个特异性的低反射峰并随时间而逐渐变化;在注射ICG 3min时,本特异性低反射峰值达到最强,反射光谱的特征性变化可以为实现最佳OCT图像效果提供时间点。此外,ICG注射后的脑动脉OCT信号衰减系数为24.692±1.471,明显高于未注射ICG时15.088±1.602(p<0.01)。实验结果说明ICG可以增加血管对近红外光的吸收,为增强血管的检测能力提供理论参考,也为无损监测血管病变、肿瘤血管新生及血液动力学变化提供一种可行性检测手段。

The scope of this research lies in the effects of indocyanine green （ICG） on the near-infrared optical properties and op- tical coherence tomographic image of cerebral blood vessel in vivo in rats. The skulls of SD rats were opened under nembutal anesthesia to expose and mark the middle cerebral artery. The reflectance spectra of middle cerebral artery were monitored by Vis/ NIR spectrometer and the optical attenuation coefficients of middle cerebral artery were detected by optical coherence tornography （OCT） when indocyanine green was administrated intravenously through tail veins. It was shown that the reflectance spectra of middle cerebral artery could provide guidance for OCT image, where characteristic changes appeared around 800 nm, an absorption peak of indocyanine green. Additionally, significant difference （p〈0. 01） was observed between the optical attenuation coefficients of middle cerebral artery with and without indocyanine green, which were 24. 692± 1. 471 and 15. 088±1. 602, respectively. It was concluded that indocyanine green, as an optical contrast agent to enhance detection of cerebral artery by the reflec- tance spectra and OCT imaging, has the potential for monitoring and imaging of cerebral blood vessels.