Susceptibility-based functional brain mapping by 3D deconvolution of an MR-phase activation map
Susceptibility-based functional brain mapping by 3D deconvolution of an MR-phase activation map
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DOI：
10.1016/j.jneumeth.2013.03.003
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发表时间：
2013-05-30
影响因子：
3
通讯作者：
Calhoun, Vince D.
中科院分区：
文献类型：
--
作者：
Chen, Zikuan;Liu, Jingyu;Calhoun, Vince D.
用于脑成像的T2* 加权磁共振成像（T2*MRI）的潜在来源是磁化率（用chi表示）。T2*MRI输出由幅度和相位信息组成的复值MR图像。最近的研究已经表明，幅度和相位图像在形态上与源chi不同，这主要是由于3D卷积，并且源chi可以通过计算机逆MRI（CIMRI）从复杂的MR图像重建。因此，我们可以通过重复CIMRI以在每个时间点重建3D chi体积，从从脑功能MRI研究获得的复杂4D MR数据集获得4D chi数据集。因为重建的chi是一个更直接的表示比MR图像的神经元活动，我们提出了一种方法，以chi为基础的功能性脑映射，这是数字特征的时间相关图chi刺激任务的反应。在T2*MRI的线性成像条件下，我们证明了可以通过CIMRI从MR相位图计算chi激活图。我们使用数值模拟和Gd幻影实验验证我们的方法。我们还分析了真实的数据，从手指敲击视觉实验，并表明，基于卡的功能映射提供额外的激活细节（正相关和负相关模式的形式）超出了传统的MR幅度为基础的映射所产生的。(C)2013爱思唯尔有限公司版权所有。
The underlying source of T2*-weighted magnetic resonance imaging (T2*MRI) for brain imaging is magnetic susceptibility (denoted by chi). T2*MRI outputs a complex-valued MR image consisting of magnitude and phase information. Recent research has shown that both the magnitude and the phase images are morphologically different from the source chi, primarily due to 3D convolution, and that the source chi can be reconstructed from complex MR images by computed inverse MRI (CIMRI). Thus, we can obtain a 4D chi dataset from a complex 4D MR dataset acquired from a brain functional MRI study by repeating CIMRI to reconstruct 3D chi volumes at each timepoint. Because the reconstructed chi is a more direct representation of neuronal activity than the MR image, we propose a method for chi-based functional brain mapping, which is numerically characterised by a temporal correlation map of chi responses to a stimulant task. Under the linear imaging conditions used for T2*MRI, we show that the chi activation map can be calculated from the MR phase map by CIMRI. We validate our approach using numerical simulations and Gd-phantom experiments. We also analyse real data from a finger-tapping visuomotor experiment and show that the chi-based functional mapping provides additional activation details (in the form of positive and negative correlation patterns) beyond those generated by conventional MR-magnitude-based mapping. (C) 2013 Elsevier B.V. All rights reserved.