Athena Project-Team, Inria Sophia Antipolis-Méditerranée, Sophia Antipolis, France.
Magn Reson Med. 2013 Jun;69(6):1534-40. doi: 10.1002/mrm.24736. Epub 2013 Apr 26.
In diffusion MRI, a technique known as diffusion spectrum imaging reconstructs the propagator with a discrete Fourier transform, from a Cartesian sampling of the diffusion signal. Alternatively, it is possible to directly reconstruct the orientation distribution function in q-ball imaging, providing so-called high angular resolution diffusion imaging. In between these two techniques, acquisitions on several spheres in q-space offer an interesting trade-off between the angular resolution and the radial information gathered in diffusion MRI. A careful design is central in the success of multishell acquisition and reconstruction techniques.
The design of acquisition in multishell is still an open and active field of research, however. In this work, we provide a general method to design multishell acquisition with uniform angular coverage. This method is based on a generalization of electrostatic repulsion to multishell.
We evaluate the impact of our method using simulations, on the angular resolution in one and two bundles of fiber configurations. Compared to more commonly used radial sampling, we show that our method improves the angular resolution, as well as fiber crossing discrimination.
We propose a novel method to design sampling schemes with optimal angular coverage and show the positive impact on angular resolution in diffusion MRI.
在扩散磁共振成像中，一种称为扩散谱成像的技术通过对扩散信号的笛卡尔采样，用离散傅里叶变换来重建传播子。或者，在 q 球成像中可以直接重建方向分布函数，提供所谓的高角分辨率扩散成像。在这两种技术之间，在 q 空间的几个球上进行采集，在扩散磁共振成像中提供了角分辨率和径向信息之间的有趣折衷。在多壳层采集和重建技术的成功中，精心的设计是核心。
然而，多壳层采集的设计仍然是一个开放和活跃的研究领域。在这项工作中，我们提供了一种通用的方法，用于设计具有均匀角覆盖的多壳层采集。该方法基于对多壳层静电排斥的推广。
我们使用模拟评估了我们的方法在纤维结构的单束和双束中的角分辨率的影响。与更常用的径向采样相比，我们表明我们的方法提高了角分辨率和纤维交叉分辨能力。
我们提出了一种新的方法来设计具有最佳角覆盖的采样方案，并展示了其对扩散磁共振成像中角分辨率的积极影响。
