Patient scans from MRI often suffer from noise, which hampers the diagnostic capability of such images. As a method to mitigate such artifact, denoising is largely studied both within the medical imaging community and beyond the community as a general subject. However, recent deep neural network-based approaches mostly rely on the minimum mean squared error (MMSE) estimates, which tend to produce a blurred output. Moreover, such models suffer when deployed in real-world sitautions: out-of-distribution data, and complex noise distributions that deviate from the usual parametric noise models. In this work, we propose a new denoising method based on score-based reverse diffusion sampling, which overcomes all the aforementioned drawbacks. Our network, trained only with coronal knee scans, excels even on out-of-distribution in vivo liver MRI data, contaminated with complex mixture of noise. Even more, we propose a method to enhance the resolution of the denoised image with the same network. With extensive experiments, we show that our method establishes state-of-the-art performance, while having desirable properties which prior MMSE denoisers did not have: flexibly choosing the extent of denoising, and quantifying uncertainty.

该论文提出了一种新的去噪方法基于得分的反向扩散采样，通过该方法，我们的网络在仅训练冠状膝关节扫描的情况下，在复杂的混合噪声污染的体内肝脏MRI数据中表现卓越，并提出了一种用同一网络提高去噪图像分辨率的方法，通过大量实验表明，我们的方法在具有先进性能的同时具有优良的特性，这些先前的MMSE去噪器没有的：自由选择去噪程度和量化不确定性。

使用正则化逆扩散进行MR图像降噪和超分辨率