目的探讨不同缺血程度脑组织在0.1~2.0THz波段的时域光谱特征。方法采用线栓法制备大鼠大脑中动脉闭塞模型,利用透射式太赫兹时域光谱(THz—TDS)测量缺血3、6、12、24h脑组织的太赫兹时域光谱,分析吸收系数曲线中出现的峰-谷吸收系数差值(PVD)。结果不同程度缺血脑组织太赫兹波吸收系数曲线与正常脑组织存在明显差异;在1.4、1.5、1.6、1.7、1.8、1.9THz频率处PVD值的减少程度与脑组织缺血严重程度正相关(P〈0.05);太赫兹所检测的缺血区域细胞密度明显降低,脑含水量明显升高。结论太赫兹时域光谱可于缺血早期(3h内)检测出脑组织缺血,具有较好的应用前景。
Objective To explore Terabertz time - domain spectra of ischemic brain tissue in different time on rats. Methods The model of middle cerebral artery occlusion (MACO) was established and transmissive Terahertz time - domain spectroscopy of the brain tissue of occlusive lesions was measured. The Peaks -Valley difference (PVD) in absorption coefficient curve was analyzed. Results The ischemia brain tissues in 3, 6, 12 and 24 hours had significant differences with normal brain tissue. The PVD value was decreased significantly in 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 THz frequencies( P 〈0.05 ). The cell density of ischemic brain tissue was significantly reduced and the brain water content was significantly higher. Conclusions erahertz time - domain spectroscopy could detect ischemia within 3 hours after artery occlusion. PVD value is positively related to the severity of brain tissue ischemia.