Estimating blood and brain concentrations and blood-to-brain influx by magnetic resonance imaging with step-down infusion of Gd-DTPA in focal transient cerebral ischemia and confirmation by quantitative autoradiography with Gd-[14C]DTPA
Estimating blood and brain concentrations and blood-to-brain influx by magnetic resonance imaging with step-down infusion of Gd-DTPA in focal transient cerebral ischemia and confirmation by quantitative autoradiography with Gd-[14C]DTPA
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DOI：
10.1038/jcbfm.2009.20
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发表时间：
2009-05-01
影响因子：
6.3
通讯作者：
Nagaraja, Tavarekere N.
中科院分区：
文献类型：
--
作者：
Knight, Robert A.;Karki, Kishor;Nagaraja, Tavarekere N.
使用维持恒定的钆-二乙烯-三胺五乙酸（Gd-DTPA）血液浓度的静脉降压输注程序和磁共振成像（MRI）来定位和量化短暂性脑缺血大鼠模型中的血脑屏障（BBB）开放（n = 7）。使用MRI-Patlak图估计来自这些区域的Gd-DTPA的血-脑内流速率常数（Ki）值，并与Gd-[C-14] DTPA的Ki值进行比较，该Ki值在相同大鼠中使用相同的降压输注、定量放射自显影（QAR）和单次方程在几分钟后测定。Gd-DTPA和Gd-[C-14] DTPA的标准化血浆浓度-时间积分相同，表明MRI方案可可靠估计血浆Gd-DTPA水平。在6只BBB开放的大鼠中，观察到14个空间相似的血管外Gd-DTPA增强和Gd-[C-14] DTPA渗漏区域，包括一个非常小的区域。Gd-[C-14] DTPA的终末组织-血浆比值在这些区域有略高于Gd-DTPA的趋势，但差异不显著。Gd-DTPA的MRI导出的K-i值与Gd[C-14] DTPA获得的K-i值非常一致且相关性良好。总之，MRI估计的Gd-DTPA浓度在血浆和大脑和流入率是定量和空间准确的逐步下降输注。脑血流与代谢杂志（2009）29，1048-1058; doi：10.1038/jcbfm.2009.20; 2009年3月25日在线发表
An intravenous step-down infusion procedure that maintained a constant gadolinium-diethylene-triaminepentaacetic acid (Gd-DTPA) blood concentration and magnetic resonance imaging (MRI) were used to localize and quantify the blood-brain barrier (BBB) opening in a rat model of transient cerebral ischemia (n = 7). Blood-to-brain influx rate constant (K-i) values of Gd-DTPA from such regions were estimated using MRI-Patlak plots and compared with the K-i values of Gd-[C-14] DTPA, determined minutes later in the same rats with an identical step-down infusion, quantitative autoradiography (QAR), and single-time equation. The normalized plasma concentration-time integrals were identical for Gd-DTPA and Gd-[C-14] DTPA, indicating that the MRI protocol yielded reliable estimates of plasma Gd-DTPA levels. In six rats with a BBB opening, 14 spatially similar regions of extravascular Gd-DTPA enhancement and Gd-[C-14] DTPA leakage, including one very small area, were observed. The terminal tissue-plasma ratios of Gd-[C-14] DTPA tended to be slightly higher than those of Gd-DTPA in these regions, but the differences were not significant. The MRI-derived K-i values for Gd-DTPA closely agreed and correlated well with those obtained for Gd[C-14] DTPA. In summary, MRI estimates of Gd-DTPA concentration in the plasma and brain and the influx rate are quantitatively and spatially accurate with step-down infusions. Journal of Cerebral Blood Flow & Metabolism (2009) 29, 1048-1058; doi:10.1038/jcbfm.2009.20; published online 25 March 2009