Cohen Y, Sanada T, Pitts L H, Chang L H, Nishimura M C, Weinstein P R, Litt L, James T L
Department of Pharmaceutical Chemistry, University of California, San Francisco 94143.
Magn Reson Med. 1991 Jan;17(1):225-36. doi: 10.1002/mrm.1910170125.
Detailed temporal and spatial distributions of lactate production are presented for graded fluid-percussion brain injury in the rat. A one-dimensional proton spin-echo spectroscopic imaging (1D SESI) technique, performed with a surface coil, is presented and evaluated. This technique, which represents a practical compromise, provides spatially localized proton nuclear magnetic resonance (NMR) brain spectra from a series of small voxels (less than 0.15 cm3) in less than 10 min, thus enabling both spatial and temporal monitoring of lactate production. These high-resolution lactate maps are correlated with hyperintense regions observed in T2-weighted images taken 10 h after impact, which, in turn, correlate with histology. The data demonstrate that, following severe trauma there is delayed production and propagation of lactate to regions of the brain that are remote from the trauma site. The extent of lactate production depends on the severity of impact. More significantly, the data show that following severe trauma, local lactate concentrations exceed 15 mumol/g, the concentration that has been claimed as the threshold for brain injury. Therefore high lactate levels cannot be ruled out a priori as a possible factor in brain injury following severe head trauma.
本文呈现了大鼠分级液体冲击性脑损伤中乳酸生成的详细时空分布情况。介绍并评估了一种使用表面线圈进行的一维质子自旋回波光谱成像（1D SESI）技术。该技术是一种实际的折中方案，可在不到10分钟的时间内从一系列小体素（小于0.15立方厘米）获取空间定位的质子核磁共振（NMR）脑谱，从而实现对乳酸生成的时空监测。这些高分辨率乳酸图谱与撞击后10小时所拍摄的T2加权图像中观察到的高信号区域相关，而这些高信号区域又与组织学相关。数据表明，严重创伤后，乳酸会延迟生成并扩散至远离创伤部位的脑区。乳酸生成的程度取决于撞击的严重程度。更重要的是，数据显示严重创伤后，局部乳酸浓度超过15微摩尔/克，而该浓度被认为是脑损伤的阈值。因此，不能先验地排除高乳酸水平作为严重头部创伤后脑损伤可能因素的可能性。
