Meyer J S, Hayman L A, Amano T, Nakajima S, Shaw T, Lauzon P, Derman S, Karacan I, Harati Y
Stroke. 1981 Jul-Aug;12(4):426-36. doi: 10.1161/01.str.12.4.426.
Non-invasive methods are described for estimating local cerebral blood flows (LCBF) and partition coefficients (L lambda) during inhalation of 35% stable xenon gas (Xes) in oxygen during CT scanning. After denitrogenation by 100% oxygen breathing, 35% Xes is breathed for 7-8 minutes to minimize subanesthetic effects. Mean changes in brain Hounsfield units extrapolated to 15 minutes were 7.7 units for white matter and 5.3 units for gray matter. They were measured from volumes 80 cubic mm (10 mm2 area x 8 mm), or larger with an EMI 1010 scanner at 1 minute intervals. These data were used for computing LCBFs and L lambdas. Irradiation measured at the center of brain slices was 1 rad per minute. To calculate L lambdas about 6 exposures are necessary, thereafter, each 1 minute scan provides LCBF measurements for 2 adjacent 8 mm slices. Reproducibility for LCBF was r = 0.85 (P less 0.001). Mean L lambdas were 0.86 +/- 0.08 for gray and 1.34 +/- 0.10 for white matter. Normative mean flows (mls/100 g brain/min) were: basal ganglia = 79.6 +/- 9.3, cortex = 82.3 +/- 8.5, white matter = 29.2 +/- 5.9, midbrain tegmentum = 94.3 +/- 14.8, cerebellar cortex = 80.1 +/- 10.9, dorsal pons = 89.3 +/- 4.7, brachium pontis = 35.0 +/- 4.2. Subject finger exercises produced increases of LCBF in contralateral pre-central and post-central gyri. Eye closure decreased flow values limited to the visual system. Gray matter flow values diffusely decreased in non-REM sleep but increased above normal in REM sleep. Cerebral infarction and hemorrhage resulted in zones of zero flow with borders having reduced lambdas and low flows attributed to edema.
本文描述了一种非侵入性方法，用于在CT扫描期间吸入35%的稳定氙气（Xe）和氧气混合气时估计局部脑血流量（LCBF）和分配系数（Lλ）。在通过呼吸100%氧气进行去氮后，吸入35%的Xe持续7 - 8分钟，以尽量减少亚麻醉效应。外推至15分钟时，脑Hounsfield单位的平均变化为：白质7.7单位，灰质5.3单位。使用EMI 1010扫描仪以1分钟的间隔从80立方毫米（10平方毫米面积×8毫米）或更大的体积进行测量。这些数据用于计算LCBF和Lλ。在脑切片中心测量的辐射剂量为每分钟1拉德。为了计算Lλ，大约需要6次曝光，此后，每次1分钟的扫描可为相邻的2个8毫米切片提供LCBF测量值。LCBF的重现性为r = 0.85（P < 0.001）。灰质的平均Lλ为0.86±0.08，白质为1.34±0.10。正常平均血流量（毫升/100克脑/分钟）为：基底神经节 = 79.6±9.3，皮质 = 82.3±8.5，白质 = 29.2±5.9，中脑被盖 = 94.3±14.8，小脑皮质 = 80.1±10.9，脑桥背侧 = 89.3±4.7，脑桥臂 = 35.0±4.2。受试者手指运动使对侧中央前回和中央后回的LCBF增加。闭眼使仅限于视觉系统的血流值降低。非快速眼动睡眠时灰质血流值普遍降低，但在快速眼动睡眠时高于正常水平增加。脑梗死和脑出血导致血流为零的区域，其边界处的λ降低且血流因水肿而减少。
