Diffusion MRI (dMRI) is an important neuroimaging technique with high acquisition costs. Deep learning approaches have been used to enhance dMRI and predict diffusion biomarkers through undersampled dMRI. To generate more comprehensive raw dMRI, generative adversarial network based methods are proposed to include b-values and b-vectors as conditions, but they are limited by unstable training and less desirable diversity. The emerging diffusion model (DM) promises to improve generative performance. However, it remains challenging to include essential information in conditioning DM for more relevant generation, i.e., the physical principles of dMRI and white matter tract structures. In this study, we propose a physics-guided diffusion model to generate high-quality dMRI. Our model introduces the physical principles of dMRI in the noise evolution in the diffusion process and introduce a query-based conditional mapping within the difussion model. In addition, to enhance the anatomical fine detials of the generation, we introduce the XTRACT atlas as prior of white matter tracts by adopting an adapter technique. Our experiment results show that our method outperforms other state-of-the-art methods and has the potential to advance dMRI enhancement.

本研究提出了一种基于物理原理的扩散模型来生成高质量的扩散磁共振成像，引入了扩散过程中的噪声演化物理原理和基于查询的条件映射，并通过采用适配器技术引入XTRACT图谱作为白质束的先验知识，实验结果表明我们的方法优于其他最先进的方法，并具有推进扩散磁共振成像增强的潜力。

Phy-Diff: 物理导向的沙漏扩散模型用于扩散MRI合成