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arXiv 2212.08034eess.IV

通过条件扩散概率模型生成逼真的大脑MRI

Generating Realistic Brain MRIs via a Conditional Diffusion Probabilistic Model

Wei Peng, Ehsan Adeli, Tomas Bosschieter, Sang Hyun Park, Qingyu Zhao, Kilian M. Pohl

AI总结:

针对MRI获取成本高导致训练数据不足的问题,提出一种内存高效的条件扩散概率模型(cDPM),通过2D切片生成与注意力机制学习切片间依赖,生成高质量且解剖一致的3D大脑MRI,有效增加训练集多样性。

摘要:

由于获取MRI成本高昂,神经科学研究难以获得足够数量的MRI来妥善训练深度学习模型。这一挑战可以通过MRI合成来缓解,其中生成对抗网络(GANs)很受欢迎。然而,GANs通常不稳定,且难以创建多样化和高质量的数据。一个更稳定的替代方案是采用细粒度训练策略的扩散概率模型(DPMs)。为了克服其对大量计算资源的需求,我们提出了一种条件DPM(cDPM),通过一种内存高效的过程来生成逼真的大脑MRI。为此,我们训练一个2D cDPM,以同一MRI的另一部分切片为条件生成MRI子体积。通过在条件切片和目标切片之间使用任意组合来生成切片,该模型仅需有限的计算资源即可学习切片之间的相互依赖关系,即使它们在空间上相距甚远。在通过注意力网络学习这些依赖关系之后,通过重复应用cDPM来生成新的解剖结构一致的3D大脑MRI。我们的实验表明,我们的方法能够生成高质量的3D MRI,其分布与真实MRI相似,同时仍能使训练集多样化。代码可在https://github.com/xiaoiker/mask3DMRI_diffusion获取,也将作为MONAI的一部分发布在https://github.com/Project-MONAI/GenerativeModels。

英文摘要:

As acquiring MRIs is expensive, neuroscience studies struggle to attain a sufficient number of them for properly training deep learning models. This challenge could be reduced by MRI synthesis, for which Generative Adversarial Networks (GANs) are popular. GANs, however, are commonly unstable and struggle with creating diverse and high-quality data. A more stable alternative is Diffusion Probabilistic Models (DPMs) with a fine-grained training strategy. To overcome their need for extensive computational resources, we propose a conditional DPM (cDPM) with a memory-efficient process that generates realistic-looking brain MRIs. To this end, we train a 2D cDPM to generate an MRI subvolume conditioned on another subset of slices from the same MRI. By generating slices using arbitrary combinations between condition and target slices, the model only requires limited computational resources to learn interdependencies between slices even if they are spatially far apart. After having learned these dependencies via an attention network, a new anatomy-consistent 3D brain MRI is generated by repeatedly applying the cDPM. Our experiments demonstrate that our method can generate high-quality 3D MRIs that share a similar distribution to real MRIs while still diversifying the training set. The code is available at https://github.com/xiaoiker/mask3DMRI_diffusion and also will be released as part of MONAI, at https://github.com/Project-MONAI/GenerativeModels.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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