Localized NMR spectroscopy and functional mapping of the brain.

同时应用局部质子磁共振波谱(1H-MRS)和激光多普勒血流计(LDF)，我们可以同时观察麻醉兔脑局部乳酸水平和局部血流量(RBF)的变化。1H-MRS的体素(8 mm-立方体)主要位于丘脑区，对侧在同一区域记录RBF。使用体模模型对1H-MRS中的局部化进行了评估，证明在实际中是令人满意的。低氧时，乳酸逐渐升高，而RBF迅速升高。尽管RBF增加，但氧供给量(动脉血氧含量(O2 CT)乘以RBF)减少。低氧30min内乳酸升高与低氧时氧输送不足呈直线相关(相关系数R2=0.68，n=14，P&lt；0.001)。在随后的恢复期，RBF缓慢下降，而O2 CT迅速回升至对照水平。低氧后RFb恢复率与乳酸升高呈线性相关(偏相关系数R2=0.72，n=14，p&lt；0.001)。

Simultaneous applications of localized proton magnetic resonance spectroscopy (1H-MRS) and laser doppler flowmetry (LDF) allowed us to observe concurrent changes in regional lactate level and regional blood flow (rBF) in the anesthetized rabbit brain. The voxel (8mm-cubic) for 1H-MRS was located mostly in the thalamic area, and the rBF was recorded in the same area contralaterally. The localization in the 1H-MRS was assessed by using a phantom model and was proved to be practically satisfactory. During hypoxia, lactate increased gradually, while the rBF increased rapidly. Despite the increase in rBF,the oxygen delivery, which was the oxygen content in arterial blood (O2 CT) multiplied by the rBF,decreased. There was a linear correlation between the increase in lactate in last ten minutes during the thirty minutes hypoxia and deficiency in the oxygen delivery during hypoxia (correlation coefficience ; r2=0.68, n=14, P<0.001). In the subsequent recovery period, the rBF decreased slowly, while the O2 CT increased rapidly back to the control level. This rate of rFB recovery after hypoxia was linearly correlated with the increase in lactate (partial correlation coefficience ; r2=0.72, n=14, p<0.001).