Arterial Cerebral Blood Volume-Weighted Functional MRI Using Pseudocontinuous Arterial Spin Tagging (AVAST)
Arterial Cerebral Blood Volume-Weighted Functional MRI Using Pseudocontinuous Arterial Spin Tagging (AVAST)
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DOI：
10.1002/mrm.25220
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发表时间：
2015-03-01
影响因子：
3.3
通讯作者：
Garcia, Luis Hernandez
中科院分区：
文献类型：
--
作者：
Jahanian, Hesamoddin;Peltier, Scott;Garcia, Luis Hernandez
神经血管调节主要发生在动脉和小动脉水平，包括对引起血氧水平依赖（BOLD）效应的神经激活的反应。本研究旨在建立一种适用于功能影像学研究的动脉脑血容量（aCBV）信号快速成像框架。方法利用标签在血管中的动力学特性，开发了一种伪连续动脉自旋标记技术，以实现基于aCBV的造影，而灌注信号的污染很小。这种技术为每个主题量身定制标记的持续时间和重复时间。该技术被称为AVAST，在运动-视觉激活范例中与BOLD成像和标准（灌注加权）动脉自旋标记（ASL）技术进行了经验比较。结果标准ASL法、AVAST法和BOLD法的平均激活区z分数分别为4.25、5.52和7.87。与标准ASL测量结果相比，AVAST获得的aCBV对比度平均信噪比提高80%，平均信噪比提高95%。结论在功能MRI实验中，avast比标准ASL技术具有更高的激活检测灵敏度和时间分辨率，同时保留了其定量性质和统计优势。AVAST在病理状况的临床研究、认知功能的纵向研究和需要持续病程的研究中尤其有用。中华医学杂志，2015,33(3):563 - 564。(c) 2014 Wiley期刊公司
PurposeNeurovascular regulation, including responses to neural activation that give rise to the blood oxygenation level-dependent (BOLD) effect, occurs mainly at the arterial and arteriolar level. The purpose of this study is to develop a framework for fast imaging of arterial cerebral blood volume (aCBV) signal suitable for functional imaging studies.MethodsA variant of the pseudocontinuous arterial spin tagging technique was developed in order to achieve a contrast that depends on aCBV with little contamination from perfusion signal by taking advantage of the kinetics of the tag through the vasculature. This technique tailors the tagging duration and repetition time for each subject. The proposed technique, called AVAST, is compared empirically with BOLD imaging and standard (perfusion-weighted) arterial spin labeling (ASL) technique, in a motor-visual activation paradigm.ResultsThe average Z-scores in the activated area obtained over all the subjects were 4.25, 5.52, and 7.87 for standard ASL, AVAST, and BOLD techniques, respectively. The aCBV contrast obtained from AVAST provided 80% higher average signal-to-noise ratio and 95% higher average contrast-to-noise ratio compared with that of the standard ASL measurements.ConclusionAVAST exhibits improved activation detection sensitivity and temporal resolution over the standard ASL technique, in functional MRI experiments, while preserving its quantitative nature and statistical advantages. AVAST particularly could be useful in clinical studies of pathological conditions, longitudinal studies of cognitive function, and studies requiring sustained periods of the condition. Magn Reson Med 73:1053-1064, 2015. (c) 2014 Wiley Periodicals, Inc.