Resolution of complex tissue microarchitecture using the diffusion orientation transform (DOT)
Resolution of complex tissue microarchitecture using the diffusion orientation transform (DOT)
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DOI：
10.1016/j.neuroimage.2006.01.024
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发表时间：
2006-07-01
期刊：
影响因子：
5.7
通讯作者：
Mareci, Thomas H.
中科院分区：
文献类型：
--
作者：
Ozarslan, Evren;Shepherd, Timothy M.;Mareci, Thomas H.
本文描述了一种利用多向扩散加权磁共振(MR)数据准确、快速地绘制纤维取向图的方法。该方法利用了水的位移概率与球坐标表示的扩散衰减磁共振信号之间的傅里叶变换关系。在假设MR信号呈指数衰减的情况下，对傅立叶积分的径向部分进行了解析计算。结果函数的值在远离原点的固定距离处求值。这些函数的球谐变换得到了固定半径球面上概率的拉普拉斯级数系数。或者，可以使用勒让德多项式非参数地计算概率值。从切除的大鼠神经组织数据计算的方位图表明，这项技术能够准确地解析解剖区域(如视交叉)中的交叉纤维。该方法是对多指数扩散加权信号衰减的一种简单扩展。所开发的方法将提高纤维束成像方案的可靠性，并可能使正确识别神经系统功能连接区域之间的神经连接成为可能。(C)2006 Elsevier Inc.保留所有权利。
This article describes an accurate and fast method for fiber orientation mapping using multidirectional diffusion-weighted magnetic resonance (MR) data. This novel approach utilizes the Fourier transform relationship between the water displacement probabilities and diffusion-attenuated MR signal expressed in spherical coordinates. The radial part of the Fourier integral is evaluated analytically under the assumption that MR signal attenuates exponentially. The values of the resulting functions are evaluated at a fixed distance away from the origin. The spherical harmonic transform of these functions yields the Laplace series coefficients of the probabilities on a sphere of fixed radius. Alternatively, probability values can be computed nonparametrically using Legendre polynomials. Orientation maps calculated from excised rat nervous tissue data demonstrate this technique's ability to accurately resolve crossing fibers in anatomical regions such as the optic chiasm. This proposed methodology has a trivial extension to multiexponential diffusion-weighted signal decay. The developed methods will improve the reliability of tractography schemes and may make it possible to correctly identify the neural connections between functionally connected regions of the nervous system. (c) 2006 Elsevier Inc. All rights reserved.