Weierstrass Institute for Applied Analysis and Stochastics, Berlin, Germany.
Med Image Anal. 2012 Aug;16(6):1142-55. doi: 10.1016/j.media.2012.05.007. Epub 2012 May 24.
We introduce an algorithm for diffusion weighted magnetic resonance imaging data enhancement based on structural adaptive smoothing in both voxel space and diffusion-gradient space. The method, called POAS, does not refer to a specific model for the data, like the diffusion tensor or higher order models. It works by embedding the measurement space into a space with defined metric, in this case the Lie group of three-dimensional Euclidean motion SE(3). Subsequently, pairwise comparisons of the values of the diffusion weighted signal are used for adaptation. POAS preserves the edges of the observed fine and anisotropic structures. It is designed to reduce noise directly in the diffusion weighted images and consequently also to reduce bias and variability of quantities derived from the data for specific models. We evaluate the algorithm on simulated and experimental data and demonstrate that it can be used to reduce the number of applied diffusion gradients and hence acquisition time while achieving a similar quality of data, or to improve the quality of data acquired in a clinically feasible scan time setting.
我们介绍了一种基于体素空间和扩散梯度空间结构自适应平滑的扩散加权磁共振成像数据增强算法。该方法称为 POAS,它不针对数据的特定模型(如扩散张量或更高阶模型)。它的工作原理是将测量空间嵌入到具有定义度量的空间中,在这种情况下是三维欧几里得运动 SE(3)的李群。随后,使用扩散加权信号的值进行成对比较以进行自适应处理。POAS 保留了观察到的精细和各向异性结构的边缘。它旨在直接在扩散加权图像中减少噪声,从而减少特定模型数据衍生量的偏差和变异性。我们在模拟和实验数据上评估了该算法,并证明它可用于减少应用的扩散梯度数量,从而缩短采集时间,同时保持数据质量相似,或者在临床可行的扫描时间设置下提高数据质量。