Boosting the sampling efficiency of q-ball imaging using multiple wavevector fusion
Boosting the sampling efficiency of q-ball imaging using multiple wavevector fusion
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DOI：
10.1002/mrm.21090
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发表时间：
2007-02-01
影响因子：
3.3
通讯作者：
Tuch, David S.
中科院分区：
文献类型：
--
作者：
Khachaturian, Mark H.;Wisco, Jonathan J.;Tuch, David S.
q-Ball 成像 (QBI) 是一种高角分辨率扩散成像 (HARDI) 方法，能够解析复杂的亚体素白质 (WM) 结构。 QBI 需要对扩散信号和大扩散波矢进行时间密集型采样。在这里，我们描述了一种 QBI 重建方案，称为多波矢量融合（MWF），它大大提高了 QBI 的采样效率和信噪比（SNR）。 MWF 重建通过非线性融合来自单独的低和高波矢量采集的扩散信号来进行。波矢量的组合提供了低波矢量信号的高SNR以及高波矢量信号的高角度对比噪声比(CNR)和峰值分离的优点。 MWF 程序提供了一个结合扩散张量成像 (DTI) 和 QBI 的框架。数值模拟表明，DTI 和 QBI 的 MWF 比单独的 QBI 提供了更准确的扩散取向分布函数 (ODF) 估计。准确率的提高可以转化为 274-377% 的效率增益。提出了一种体素内峰值连通性度量（IPCM），用于计算 ODF 与其相邻体素之间的峰值连通性。在人类 WM 中，MWF 揭示了比 QBI 更详细的 WM 架构，正如 IPCM 对所有呈现的采样方案所测量的那样。 Magn Reson Med 57: 289-296, 2007。(c) 2007 Wiley-Liss, Inc.
q-Ball imaging (QBI) is a high-angular-resolution diffusion imaging (HARDI) method that is capable of resolving complex, subvoxel white matter (WM) architecture. QBI requires time-intensive sampling of the diffusion signal and large diffusion wavevectors. Here we describe a reconstruction scheme for QBI, termed multiple wavevector fusion (MWF), that substantially boosts the sampling efficiency and signal-to-noise ratio (SNR) of QBI. The MWF reconstruction operates by nonlinearly fusing the diffusion signal from separate low and high wavevector acquisitions. The combination of wavevectors provides the benefits of the high SNR of the low wavevector signal and the high angular contrast-to-noise ratio (CNR) and peak separation of the high wavevector signal. The MWF procedure provides a framework for combining diffusion tensor imaging (DTI) and QBI. Numerical simulations show that MWF of DTI and QBI provides a more accurate estimate of the diffusion orientation distribution function (ODF) than QBI alone. The accuracy improvement can be translated into an efficiency gain of 274-377%. An intravoxel peak connectivity metric (IPCM) is presented that calculates the peak connectivity between an ODF and its neighboring voxels. In human WM, MWF reveals more detailed WM architecture than QBI as measured by the IPCM for all sampling schemes presented. Magn Reson Med 57: 289-296, 2007. (c) 2007 Wiley-Liss, Inc.