Measuring blood volume and vascular transfer constant from dynamic, T*2-weighted contrast-enhanced MRI
Measuring blood volume and vascular transfer constant from dynamic, T*2-weighted contrast-enhanced MRI
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DOI：
10.1002/mrm.20049
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发表时间：
2004-05-01
影响因子：
3.3
通讯作者：
Tofts, PS
中科院分区：
文献类型：
--
作者：
Johnson, G;Wetzel, SG;Tofts, PS
动态增强磁共振成像(Demri)越来越多地被用来评估大脑微循环。分析Demri数据有两种不同的方法。血管内指示剂稀释理论被用来估计血容量(和灌注量)，通常是根据第一次团注的T(2)或T(2)(*)加权图像。然而，该理论假设示踪剂(即造影剂)保持在血管内，而当血脑屏障(BBB)受损时，情况往往并非如此。此外，该方法不提供关于血管转移常数的信息。首次通过后的T(1)加权图像的药代动力学模型分析确实给出了血管传递常数和血管外、细胞外空间(EES)的体积，但它们通常无法给出血容量的估计。在这项研究中，我们将药代动力学建模应用于示踪剂丸第一次通过的动态T(2)(*)加权成像。这种方法，我们称之为首过药代动力学模型(FPPM)，给出了血容量、血管传输常数和EES容量的估计。该方法应用于26例经手术证实的肿瘤患者(10例多形性胶质母细胞瘤、6例淋巴瘤和10例脑膜瘤)。血容量和转移常数的测量结果与已知的这些肿瘤的生理学特征一致。《医学评论》51：961-968,2004。(C)2004年Wiley-Liss公司
Dynamic, contrast-enhanced MRI (deMRI) is increasingly being used to evaluate cerebral microcirculation. There are two different approaches for analyzing deMRI data. Intravascular indicator dilution theory has been used to estimate blood volume (and perfusion), usually from T(2)- or T(2)(*)-weighted images of the first pass of the bolus. However, the theory assumes that the tracer (i.e., contrast agent) remains intravascular, which is often not the case when the blood-brain barrier (BBB) is damaged. Furthermore, the method provides no information on the vascular transfer constant. Pharmacokinetic modeling analyses of T(1)-weighted images after first pass do give values of the vascular transfer constant and the volume of the extravascular, extracellular space (EES), but they generally are unable to give estimates of blood volume. In this study we apply pharmacokinetic modeling to dynamic T(2)(*)-weighted imaging of the first pass of a tracer bolus. This method, which we call first-pass pharmacokinetic modeling (FPPM), gives an estimate of the blood volume, vascular transfer constant, and EES volume. The method was applied to a group of 26 patients with surgically proven tumors (10 glioblastomas multiforme (GBMs), six lymphomas, and 10 meningiomas). The measurements of the blood volume and transfer constant were consistent with the known physiology of these tumors. Magn Reson Med 51:961-968, 2004. (C) 2004 Wiley-Liss, Inc.