Comparison of pulsed arterial spin labeling encoding schemes and absolute perfusion quantification
Comparison of pulsed arterial spin labeling encoding schemes and absolute perfusion quantification
复制标题
DOI：
10.1016/j.mri.2009.04.002
复制
发表时间：
2009-10-01
影响因子：
2.5
通讯作者：
Uludag, Kamil
中科院分区：
文献类型：
--
作者：
Cavusoglu, Mustafa;Pfeuffer, Josef;Uludag, Kamil
磁共振成像（MRI）动脉自旋标记（ASL）是一种强大的无创技术，可以通过测量脑血流量（CBF）来研究脑组织的生理状态。ASL评估磁标记动脉血流入成像体素。在过去的20年里，各种各样的ASL序列被提出，它们在实现的情况和对伪影的敏感性上有所不同。此外，还开发了几种量化方法来确定ASL磁化差图像的CBF绝对值。在这项研究中，我们评估了三种脉冲ASL序列和三种绝对定量方案。研究发现，与PICORE-Q2TIPS（带FOCI脉冲）和PICORE-QUIPSSII（带BASSI脉冲）相比，FAIR-QUIPSSII实现ASL的信噪比（SNR）提高了10-20%，CBF提高了18%。此外，所采用的量化方案可能导致CBF值的差异高达35%。我们得出结论，尽管所有定量ASL序列和CBF校准方法原则上都应该产生相似的CBF值和图像质量，但发现CBF值和信噪比存在实质性差异。因此，比较使用不同ASL序列和分析算法的研究可能会导致错误的组内和组间差异。因此，(i)应该始终使用相同的量化方案，（ii）使用局部组织质子密度进行量化应该产生最准确的CBF值，因为血液的质子密度被认为与灰质的值非常相似，尽管在未来的研究中仍需要明确的证明。(C) 2009爱思唯尔公司版权所有。
Arterial spin labeling (ASL) using magnetic resonance imaging (MRI) is a powerful noninvasive technique to investigate the physiological status of brain tissue by measuring cerebral blood flow (CBF). ASL assesses the inflow of magnetically labeled arterial blood into an imaging voxel. In the last 2 decades, various ASL sequences have been proposed which differ in their case of implementation and their sensitivity to artifacts. In addition, several quantification methods have been developed to determine the absolute value of CBF from ASL magnetization difference images. In this study, we evaluated three pulsed ASL sequences and three absolute quantification schemes. It was found that FAIR-QUIPSSII implementation of ASL yields 10-20% higher signal-to-noise ratio (SNR) and 18% higher CBF as compared with PICORE-Q2TIPS (with FOCI pulses) and PICORE-QUIPSSII (with BASSI pulses). In addition, quantification schemes employed can give rise to up to a 35% difference in CBF values. We conclude that, although all quantitative ASL sequences and CBF calibration methods Should in principle result in the similar CBF values and image quality, Substantial differences in CBF values and SNR were found. Thus, comparing Studies using different ASL sequences and analysis algorithms is likely to result in erroneous intra- and intergroup differences. Therefore, (i) the same quantification schemes should consistently be used, and (ii) quantification using local tissue proton density Should yield the most accurate CBF values because, although still requiring definitive demonstration in future studies, the proton density of blood is assumed to be very similar to the value of gray matter. (C) 2009 Elsevier Inc. All rights reserved.