Hosseinbor Ameer Pasha, Chung Moo K, Wu Yu-Chien, Alexander Andrew L
University of Wisconsin-Madison, Madison, WI, USA.
Med Image Comput Comput Assist Interv. 2011;14(Pt 2):217-25. doi: 10.1007/978-3-642-23629-7_27.
The estimation of the ensemble average propagator (EAP) directly from q-space DWI signals is an open problem in diffusion MRI. Diffusion spectrum imaging (DSI) is one common technique to compute the EAP directly from the diffusion signal, but it is burdened by the large sampling required. Recently, several analytical EAP reconstruction schemes for multiple q-shell acquisitions have been proposed. One, in particular, is Diffusion Propagator Imaging (DPI) which is based on the Laplace's equation estimation of diffusion signal for each shell acquisition. Viewed intuitively in terms of the heat equation, the DPI solution is obtained when the heat distribution between temperatuere measurements at each shell is at steady state. We propose a generalized extension of DPI, Bessel Fourier Orientation Reconstruction (BFOR), whose solution is based on heat equation estimation of the diffusion signal for each shell acquisition. That is, the heat distribution between shell measurements is no longer at steady state. In addition to being analytical, the BFOR solution also includes an intrinsic exponential smootheing term. We illustrate the effectiveness of the proposed method by showing results on both synthetic and real MR datasets.
直接从q空间扩散加权成像（DWI）信号估计总体平均传播子（EAP）是扩散磁共振成像中的一个开放问题。扩散谱成像（DSI）是一种直接从扩散信号计算EAP的常用技术，但它受到所需大量采样的困扰。最近，已经提出了几种用于多q壳采集的解析EAP重建方案。特别是其中一种是扩散传播子成像（DPI），它基于对每个壳采集的扩散信号进行拉普拉斯方程估计。从热方程直观来看，当每个壳处温度测量之间的热分布处于稳态时，可获得DPI解。我们提出了DPI的广义扩展，即贝塞尔傅里叶方向重建（BFOR），其解基于对每个壳采集的扩散信号进行热方程估计。也就是说，壳测量之间的热分布不再处于稳态。除了具有解析性之外，BFOR解还包括一个内在的指数平滑项。我们通过展示在合成和真实MR数据集上的结果来说明所提出方法的有效性。
