Wei D, Shea M, Saidel G M, Jones S C
Department of Neurosciences, Cleveland Clinic Foundation, Ohio.
J Cereb Blood Flow Metab. 1993 Jul;13(4):693-701. doi: 10.1038/jcbfm.1993.88.
A thermal measurement system to monitor cerebral blood flow (CBF) continuously from the cortical surface is evaluated in vivo. It has a temperature resolution of better than 0.001 degrees C (1 m degrees C) and can compensate for baseline temperature fluctuations in the brain tissue. A new approach has been developed to test the capability of monitoring dynamic CBF response. Transient CBF changes associated with changes in mean arterial blood pressure (MABP) caused by repeated bolus norepinephrine injections are used to examine the response of the measurement system in both the heated mode, sensitive to flow, and the unheated mode, sensitive only to temperature. Experiments on 13 rats demonstrate that changes in the MABP are closely correlated with those of temperature difference in the heated mode. Regression analysis shows a mean slope of 0.9 m degrees C/mm Hg in the heated mode, which is significantly different from zero (p < 0.002) and from the mean slope in the unheated mode (p < 0.002). This indicates that flow signal in the system output can be distinguished from the baseline thermal fluctuations. Thus, the system can be used to detect and study dynamic perfusion changes from the brain surface with minimal tissue damage. Furthermore, analysis of the data shows that the transient flow signal before autoregulation is linearly correlated with changes in MABP.
一种用于从皮质表面连续监测脑血流量（CBF）的热测量系统在体内进行了评估。它具有优于0.001摄氏度（1毫摄氏度）的温度分辨率，并且可以补偿脑组织中的基线温度波动。已开发出一种新方法来测试监测动态CBF反应的能力。由重复推注去甲肾上腺素注射引起的与平均动脉血压（MABP）变化相关的瞬态CBF变化，用于在对流量敏感的加热模式和仅对温度敏感的未加热模式下检查测量系统的反应。对13只大鼠进行的实验表明，在加热模式下，MABP的变化与温差变化密切相关。回归分析显示，加热模式下的平均斜率为0.9毫摄氏度/毫米汞柱，这与零有显著差异（p < 0.002），且与未加热模式下的平均斜率有显著差异（p < 0.002）。这表明系统输出中的流量信号可以与基线热波动区分开来。因此，该系统可用于以最小的组织损伤检测和研究脑表面的动态灌注变化。此外，数据分析表明，自动调节之前的瞬态流量信号与MABP的变化呈线性相关。
