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arXiv 2203.16680cs.CVcs.LGeess.IV
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使用 HyperMorph 学习配准超参数的影响

Learning the Effect of Registration Hyperparameters with HyperMorph

Martinos Center for Biomedical Imaging, Massachusetts General Hospital(马萨诸塞州总医院马丁诺斯生物医学成像中心);Department of Radiology, Harvard Medical School(哈佛医学院放射学系);Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology(麻省理工学院计算机科学与人工智能实验室)

Andrew Hoopes, Malte Hoffmann, Douglas N. Greve, Bruce Fischl, John Guttag, Adrian V. Dalca

AI总结:

提出 HyperMorph 框架,通过超网络学习超参数对变形场的影响,实现测试时快速高分辨率超参数搜索,提升配准效率与灵活性,避免重复训练模型。

摘要:

我们引入了 HyperMorph,这是一个促进基于学习的可变形图像配准中高效超参数调优的框架。经典配准算法执行迭代的成对优化,以计算对齐两幅图像的变形场。最近基于学习的方法利用大型图像数据集来学习一个函数,该函数能快速估计给定图像对的变形。在这两种策略中,最终空间对应关系的准确性都强烈受到某些超参数值选择的影响。然而,有效的超参数搜索会消耗大量时间和人力,因为它通常需要针对不同的固定超参数值训练多个模型,并可能导致次优配准。我们提出了一种摊销超参数学习策略,通过学习超参数对变形场的影响来减轻这一负担。我们设计了一个元网络(即超网络),它根据输入超参数预测配准网络的参数,从而构成一个单一模型,能够生成对应于给定超参数值的最优变形场。该策略在测试时实现了快速、高分辨率的超参数搜索,减少了传统方法的低效性,同时提高了灵活性。我们还展示了 HyperMorph 的额外优势,包括对模型初始化的增强鲁棒性,以及能够快速识别特定于数据集、图像对比度、任务甚至解剖区域的最优超参数值的能力,所有这些都不需要重新训练模型。我们在 http://hypermorph.voxelmorph.net 上公开了我们的代码。

英文摘要:

We introduce HyperMorph, a framework that facilitates efficient hyperparameter tuning in learning-based deformable image registration. Classical registration algorithms perform an iterative pair-wise optimization to compute a deformation field that aligns two images. Recent learning-based approaches leverage large image datasets to learn a function that rapidly estimates a deformation for a given image pair. In both strategies, the accuracy of the resulting spatial correspondences is strongly influenced by the choice of certain hyperparameter values. However, an effective hyperparameter search consumes substantial time and human effort as it often involves training multiple models for different fixed hyperparameter values and may lead to suboptimal registration. We propose an amortized hyperparameter learning strategy to alleviate this burden by learning the impact of hyperparameters on deformation fields. We design a meta network, or hypernetwork, that predicts the parameters of a registration network for input hyperparameters, thereby comprising a single model that generates the optimal deformation field corresponding to given hyperparameter values. This strategy enables fast, high-resolution hyperparameter search at test-time, reducing the inefficiency of traditional approaches while increasing flexibility. We also demonstrate additional benefits of HyperMorph, including enhanced robustness to model initialization and the ability to rapidly identify optimal hyperparameter values specific to a dataset, image contrast, task, or even anatomical region, all without the need to retrain models. We make our code publicly available at http://hypermorph.voxelmorph.net.

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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