Q-Ball imaging
Q-Ball imaging
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DOI：
10.1002/mrm.20279
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发表时间：
2004-12-01
影响因子：
3.3
通讯作者：
Tuch, DS
中科院分区：
文献类型：
--
作者：
Tuch, DS
磁共振扩散张量成像（DTI）为在体神经组织结构的定位提供了有力的工具。然而，由于张量模型的限制，DTI只能解决每个成像体素内的单个纤维取向。例如，DTI无法分辨单个体素内的纤维交叉、弯曲或扭曲。体素内纤维交叉可以使用q空间扩散成像来解决，但是q空间成像需要大的脉冲场梯度和时间密集的采样。还可以使用高角分辨率扩散成像（HARDI）信号的混合模型分解来解析体素内纤维交叉，但是混合建模需要基础扩散过程的模型。最近，已经表明，HARDI信号可以使用称为Funk-Radon变换（也称为球面Radon变换）的球面层析反演进行模型独立重建。由此产生的成像方法，称为q球成像，可以解决多个内体素纤维方向，不需要任何假设的扩散过程，如高斯或多高斯。本文回顾了q球成像的理论，并描述了一个简单的线性矩阵公式的q球重建的基础上球面径向基函数插值。开放方面的q球重建算法进行了讨论。(C)2004 Wiley-Liss，Inc.
Magnetic resonance diffusion tensor imaging (DTI) provides a powerful tool for mapping neural histoarchitecture in vivo. However, DTI can only resolve a single fiber orientation within each imaging voxel due to the constraints of the tensor model. For example, DTI cannot resolve fibers crossing, bending, or twisting within an individual voxel. Intravoxel fiber crossing can be resolved using q-space diffusion imaging, but q-space imaging requires large pulsed field gradients and time-intensive sampling. It is also possible to resolve intravoxel fiber crossing using mixture model decomposition of the high angular resolution diffusion imaging (HARDI) signal, but mixture modeling requires a model of the underlying diffusion process. Recently, it has been shown that the HARDI signal can be reconstructed model-independently using a spherical tomographic inversion called the Funk-Radon transform, also known as the spherical Radon transform. The resulting imaging method, termed q-ball imaging, can resolve multiple intravoxel fiber orientations and does not require any assumptions on the diffusion process such as Gaussianity or multi-Gaussianity. The present paper reviews the theory of q-ball imaging and describes a simple linear matrix formulation for the q-ball reconstruction based on spherical radial basis function interpolation. Open aspects of the q-ball reconstruction algorithm are discussed. (C) 2004 Wiley-Liss, Inc.