Effects of variations in the duration of diffusible-tracer infusions on calculated values of global and local cerebral blood flow.
Effects of variations in the duration of diffusible-tracer infusions on calculated values of global and local cerebral blood flow.
复制标题
扩散示踪剂输注持续时间的变化对整体和局部脑血流量计算值的影响。
DOI：
10.1007/bf01000246
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发表时间：
1992
影响因子：
3.6
通讯作者：
Duryea,RA
中科院分区：
文献类型：
--
作者：
Lear,JL;Kasliwal,R;Duryea,RA
使用双示踪剂定量数字放射自显影和碘安替比林（IAP），我们比较了局部脑血流量（LCBF）的测量使用两种不同的输液时间在同一动物。同时给大鼠输注14 C-IAP和123 I-IAP;一种示踪剂在20秒内给药，另一种在40秒内给药。然后从20微米厚的脑切片中产生成对的放射自显影图，一个主要代表123 I，另一个主要代表14 C，并将每个切片的图像数字化和处理以产生成对的LCBF数字图像。相应的LCBF图像进行定量比较的像素逐像素的基础上。与40秒相比，20秒时的总体LCBF值更大（28%），与先前报告的“下降流”现象一致。也许更重要的是，LCBF的实际模式在两个时间点之间的某些区域，如皮层，海马，丘脑和小脑不同。换句话说，计算的LCBF值的定量模式取决于示踪剂输注的持续时间，即使输注时间低于推荐限值（45秒）。因此，即使在简短的实验中，LCBF测量中的误差也可能发生在某些结构中。因为这些误差是空间相关的，而不是血流相关的，所以目前没有可以全局应用于大脑以校正它们的模型。
Using dual tracer quantitative digital autoradiography and iodoantipyrine (IAP), we compared local cerebral blood flow (LCBF) measurements using two different infusion times within the same animal. Rats were given concurrent infusions of14C-IAP and123I-IAP; one tracer was administered over 20 seconds and the other over 40 seconds. Pairs of autoradiograms, one representing predominantly123I and the other14C, were then produced from 20 micron-thick brain sections and images from each section were digitized and processed to produce pairs of digital images of LCBF. The corresponding LCBF images were compared quantitatively on a pixel-by-pixel basis. Global LCBF values were greater (28%) at 20 seconds compared to 40 seconds, consistent with the previously reported “falling flow” phenomenon. Perhaps more importantly, the actual pattern of LCBF differed in certain regions such as the cortex, hippocampus, thalamus, and cerebellum between the two time points. In other words, the quantitative patterns of calculated LCBF values were dependent upon the duration of tracer infusion, even when the infusion times were kept below recommended limits (45 seconds). Thus, errors in LCBF measurements may occur in certain structures even in brief experiments. Because these errors are spatially dependent rather than blood flow dependent, there is presently no model which can be globally applied to the brain to correct them.