Multidimensional MRI is an emerging approach that simultaneously encodes water relaxation (T₁ and T₂) and mobility (diffusion) and replaces voxel-averaged values with subvoxel distributions of those MR properties. While conventional (i.e., voxel-averaged) MRI methods cannot adequately quantify the microscopic heterogeneity of biological tissue, using subvoxel information allows to selectively map a specific T₁-T₂-diffusion spectral range that corresponds to a group of tissue elements. The major obstacle to the adoption of rich, multidimensional MRI protocols for diagnostic or monitoring purposes is the prolonged scan time. Our main goal in the present study is to evaluate the performance of a nonlocal estimation of multispectral magnitudes (NESMA) filter on reduced datasets to limit the total acquisition time required for reliable multidimensional MRI characterization of the brain. Here we focused and reprocessed results from a recent study that identified potential imaging biomarkers of axonal injury pathology from the joint analysis of multidimensional MRI, in particular voxelwise T₁-T₂ and diffusion-T₂ spectra in human Corpus Callosum, and histopathological data. We tested the performance of NESMA and its effect on the accuracy of the injury biomarker maps, relative to the co-registered histological reference. Noise reduction improved the accuracy of the resulting injury biomarker maps, while permitting data reduction of 35.7 and 59.6% from the full dataset for T₁-T₂ and diffusion-T₂ cases, respectively. As successful clinical proof-of-concept applications of multidimensional MRI are continuously being introduced, reliable and robust noise removal and consequent acquisition acceleration would advance the field towards clinically-feasible diagnostic multidimensional MRI protocols.

多维 MRI 是一种新兴方法，可同时编码水弛豫（时间₁和时间₂）和迁移率（扩散），并用这些 MR 属性的亚体素分布替换体素平均值。虽然传统的（即体素平均）MRI 方法无法充分量化生物组织的微观异质性，但使用亚体素信息可以选择性地映射特定的区域。时间₁ -时间_2-对应于一组组织元素的扩散光谱范围。采用丰富的多维 MRI 协议进行诊断或监测的主​​要障碍是扫描时间过长。我们本研究的主要目标是评估多光谱幅度非局部估计 (NESMA) 滤波器在简化数据集上的性能，以限制可靠的大脑多维 MRI 表征所需的总采集时间。在这里，我们重点关注并重新处理了最近一项研究的结果，该研究通过多维 MRI（特别是体素方面）的联合分析确定了轴突损伤病理学的潜在成像生物标志物时间₁ -时间₂、扩散-时间₂人类胼胝体的光谱和组织病理学数据。我们测试了 NESMA 的性能及其对损伤生物标志物图相对于共同注册的组织学参考的准确性的影响。降噪提高了所得到的损伤生物标志物图的准确性，同时允许完整数据集的数据减少 35.7% 和 59.6%时间₁ -时间₂、扩散-时间分别_2例。随着多维 MRI 成功的临床概念验证应用不断被引入，可靠、稳健的噪声消除和随之而来的采集加速将推动该领域朝着临床可行的诊断多维 MRI 协议发展。