Key Laboratory of Brain Functional Genomics, Institute of Cognitive Neuroscience, East China Normal University, Shanghai 20062, China.
Comput Med Imaging Graph. 2013 Jun;37(4):272-80. doi: 10.1016/j.compmedimag.2013.04.007. Epub 2013 Jun 2.
Diffusion kurtosis imaging (DKI) is a new method of magnetic resonance imaging (MRI) that provides non-Gaussian information that is not available in conventional diffusion tensor imaging (DTI). DKI requires data acquisition at multiple b-values for parameter estimation; this process is usually time-consuming. Therefore, fewer b-values are preferable to expedite acquisition. In this study, we carefully evaluated various acquisition schemas using different numbers and combinations of b-values. Acquisition schemas that sampled b-values that were distributed to two ends were optimized. Compared to conventional schemas using equally spaced b-values (ESB), optimized schemas require fewer b-values to minimize fitting errors in parameter estimation and may thus significantly reduce scanning time. Following a ranked list of optimized schemas resulted from the evaluation, we recommend the 3b schema based on its estimation accuracy and time efficiency, which needs data from only 3 b-values at 0, around 800 and around 2600 s/mm2, respectively. Analyses using voxel-based analysis (VBA) and region-of-interest (ROI) analysis with human DKI datasets support the use of the optimized 3b (0, 1000, 2500 s/mm2) DKI schema in practical clinical applications.
扩散峰度成像（DKI）是磁共振成像（MRI）的一种新方法，它提供了常规扩散张量成像（DTI）中无法获得的非高斯信息。DKI 需要在多个 b 值下进行数据采集以进行参数估计；这个过程通常很耗时。因此，为了加快采集速度，最好使用较少的 b 值。在这项研究中，我们仔细评估了使用不同数量和组合的 b 值的各种采集方案。优化了采样 b 值分布在两端的采集方案。与使用等间距 b 值（ESB）的常规方案相比，优化方案需要更少的 b 值来最小化参数估计中的拟合误差，因此可以显著减少扫描时间。在对评估结果进行排名后，我们推荐使用基于其估计准确性和时间效率的 3b 方案，该方案仅需要分别从 0、约 800 和约 2600 s/mm2 三个 b 值获得数据。使用基于体素的分析（VBA）和人类 DKI 数据集的感兴趣区域（ROI）分析的结果支持在实际临床应用中使用优化的 3b（0、1000、2500 s/mm2）DKI 方案。
