隐式神经模型用于多壳扩散 MRI 信号直接估计
Implicit Neural Models for Direct Multi-Shell Diffusion MRI Signal Estimation
一项 arXiv 预印本提出用带小波激活函数的隐式神经表示网络表示完整扩散信号,并以傅里叶特征和球谐基编码信号空间,实现超分辨与 q 空间插值。作者还引入基于组模板的预训练策略,结合非线性配准以加快单被试优化。
arXiv:2610.24034v1 Announce Type: new Abstract: Diffusion magnetic resonance imaging is a noninvasive technique that is sensitive to the motion of water molecules in human tissue. The image signal is commonly described in q-space; however, a complete coverage of this space is often infeasible due to hardware and acquisition time limitations. In this work, we propose to represent the entire diffusion signal using an implicit neural representation network with wavelet activation functions. The signal space is encoded using Fourier features and spherical harmonics basis functions for a continuous output distribution of the raw diffusion data, enabling both super-resolution and q-space interpolation. Additionally, we introduce a pretraining strategy using a group template, enabling faster per-subject optimisation when combined with nonlinear registrations of subjects into template space. We tested the method with 10 subjects from the Human Connectome Project and 26 subjects from in-house data (multidimensional diffusion MRI from a Parkinson's disease cohort). The results show that the proposed method yields high-fidelity reconstructions with significantly reduced memory requirements compared to raw diffusion-weighted images. The pretraining scheme showed good generalisability properties on data acquired with very different protocols. We further assess the method on downstream metrics relevant to diffusion MRI data from the learned representations.
中文翻译还没有生成,先显示原文。
来源:arXiv · Image and Video Processing · arxiv.org