Taguma Daiki, Ogawa Shumpei, Takemura Hiromasa
Division of Sensory and Cognitive Brain Mapping, Department of System Neuroscience, National Institute for Physiological Sciences, 38 Nishigonaka Myodaiji, Okazaki, 444-8585, Aichi, Japan.
The Graduate Institute of Advanced Studies, SOKENDAI, Hayama, Japan.
Sci Rep. 2025 Jul 16;15(1):25812. doi: 10.1038/s41598-025-10947-6.
Diffusion MRI (dMRI)-based tractometry is a non-invasive neuroimaging method for evaluating white matter tracts in living humans, capable of detecting abnormalities caused by disorders. However, measurement noise in dMRI data often compromises the signal quality. Several denoising methods for dMRI have been proposed, but the extent to which denoising affects tractometry metrics of white matter tissue properties associated with disorders remains unclear. We evaluated how denoising affects tractometry along the optic tract (OT) in patients with glaucoma. Because glaucoma damages retinal ganglion cells, the OT in patients with glaucoma is likely to exhibit tissue abnormalities. Therefore, we examined dMRI data from patients with glaucoma to evaluate how two widely used denoising methods (MPPCA and Patch2Self) affect tractometry metrics regarding the expected tissue changes in the OT. We found that denoising affected the appearance of diffusion-weighted images, increased the estimated signal-to-noise ratio, and reduced residuals in voxelwise model fitting. However, denoising had a limited impact on the differences in tractometry metrics of the OT between patients with glaucoma and controls. Moreover, we found no evidence that denoising improved the reproducibility of tractometry. These findings suggest that the current denoising methods have a limited impact when used together with a tractometry framework.
基于扩散磁共振成像（dMRI）的纤维束测量法是一种用于评估活体人类白质纤维束的非侵入性神经成像方法，能够检测由疾病引起的异常情况。然而，dMRI数据中的测量噪声常常会损害信号质量。已经提出了几种用于dMRI的去噪方法，但去噪对与疾病相关的白质组织特性的纤维束测量指标的影响程度仍不清楚。我们评估了去噪对青光眼患者视束（OT）纤维束测量的影响。由于青光眼会损害视网膜神经节细胞，青光眼患者的视束可能会出现组织异常。因此，我们检查了青光眼患者的dMRI数据，以评估两种广泛使用的去噪方法（MPPCA和Patch2Self）如何影响与视束预期组织变化相关的纤维束测量指标。我们发现，去噪影响了扩散加权图像的外观，提高了估计的信噪比，并减少了体素模型拟合中的残差。然而，去噪对青光眼患者和对照组之间视束纤维束测量指标的差异影响有限。此外，我们没有发现证据表明去噪提高了纤维束测量的可重复性。这些发现表明，当前的去噪方法与纤维束测量框架一起使用时影响有限。
