Abstract
Healthy tissue inpainting has significant applications, including the generation of pseudo-healthy baselines for tumor growth models and the facilitation of image registration. In previous editions of the BraTS Local Synthesis of Healthy Brain Tissue via Inpainting Challenge, denoising diffusion probabilistic models (DDPMs) demonstrated qualitatively convincing results but suffered from low sampling speed. To mitigate this limitation, we adapted a 2D image generation approach, combining DDPMs with generative adversarial networks (GANs) and employing a variance-preserving noise schedule, for the task of 3D inpainting. Our experiments showed that the variance-preserving noise schedule and the selected reconstruction losses can be effectively utilized for high-quality 3D inpainting in a few time steps without requiring adversarial training. We applied our findings to a different architecture, a 3D wavelet diffusion model (WDM3D) that does not include a GAN component. The resulting model, denoted as fastWDM3D, obtained a SSIM of 0.8571, a MSE of 0.0079, and a PSNR of 22.26 on the BraTS inpainting test set. Remarkably, it achieved these scores using only two time steps, completing the 3D inpainting process in 1.81 s per image. When compared to other DDPMs used for healthy brain tissue inpainting, our model is up to 800 x faster while still achieving superior performance metrics. Our proposed method, fastWDM3D, represents a promising approach for fast and accurate healthy tissue inpainting. Our code is available at this https URL.
Abstract (translated)
健康组织修复技术在多种领域有着重要的应用，包括生成肿瘤生长模型的伪正常基准以及促进图像配准。在之前的BraTS局部合成健康脑组织通过修复竞赛中，去噪扩散概率模型（DDPMs）虽然展示出了定性上令人信服的结果，但因其采样速度慢而存在局限性。为了克服这一限制，我们结合了二维图像生成方法，将DDPMs与生成对抗网络（GANs）相结合，并采用了一种保方差噪声时间表进行三维修复任务。我们的实验表明，在不使用对抗训练的情况下，这种保方差的噪声时间表和所选的重构损失可以在几步时间内有效用于高质量的三维修复。 我们还将研究结果应用于一种不同的架构——无GAN组件的三维小波扩散模型（WDM3D），从而获得了名为fastWDM3D的结果模型。该模型在BraTS修复测试集上的SSIM值为0.8571，MSE值为0.0079，PSNR值为22.26，并且仅用了两个时间步骤即完成了三维修复过程，每张图像的处理时间为1.81秒。与用于健康脑组织修复的其他DDPMs相比，我们的模型在速度上快了多达800倍，同时仍保持优异的性能指标。 我们提出的快速且准确的健康组织修复方法fastWDM3D，在三维组织修复方面展现出了巨大潜力。相关代码可在以下链接找到：[此处插入实际链接地址]
URL
https://arxiv.org/abs/2507.13146
