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arXiv 1709.02255cs.CVcs.LG
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一种包含条件生成对抗网络的术中器官运动模型

Intraoperative Organ Motion Models with an Ensemble of Conditional Generative Adversarial Networks

University College London(伦敦大学学院);University of Oxford(牛津大学)

Yipeng Hu, Eli Gibson, Tom Vercauteren, Hashim U. Ahmed, Mark Emberton, Caroline M. Moore, J. Alison Noble, Dean C. Barratt

摘要:

在本文中,我们描述了如何从单个术前MR图像直接生成患者特定的超声探头诱导的前列腺运动模型。我们的运动模型允许从密集的位移场的条件分布采样,由一个生成神经网络编码的医疗图像的条件,并接受随机噪声作为额外的输入。生成网络通过具有第二判别神经网络的极小极大优化来训练,第二判别神经网络的任务是将生成的样本与训练运动数据区分开。在这项工作中,我们提出1)联合优化第三个预处理输入图像的调节神经网络,可以有效地提取患者特定的特征进行调节; 2)将单独训练的多个生成模型与预先分离的训练数据集相结合,可以充分缓解模式坍塌的问题。使用来自143名真实患者的诊断T2加权MR图像和来自经直肠超声探头压力引起的术中前列腺运动有限元模拟的73,216个3D密集位移场进行训练,所提出的模型产生了物理上合理的前列腺特定患者运动。捕获生物力学模拟运动的能力进行了评价,使用两个错误代表模型的一般性和特异性。根据10倍交叉验证计算的中位值分别为2.8+/-0.3 mm和1.7+/-0.1 mm。我们的结论是,所介绍的方法证明了应用最先进的机器学习算法从患者图像中生成器官运动模型的可行性,并显示出对未来研究的重大承诺。

英文摘要:

In this paper, we describe how a patient-specific, ultrasound-probe-induced prostate motion model can be directly generated from a single preoperative MR image. Our motion model allows for sampling from the conditional distribution of dense displacement fields, is encoded by a generative neural network conditioned on a medical image, and accepts random noise as additional input. The generative network is trained by a minimax optimisation with a second discriminative neural network, tasked to distinguish generated samples from training motion data. In this work, we propose that 1) jointly optimising a third conditioning neural network that pre-processes the input image, can effectively extract patient-specific features for conditioning; and 2) combining multiple generative models trained separately with heuristically pre-disjointed training data sets can adequately mitigate the problem of mode collapse. Trained with diagnostic T2-weighted MR images from 143 real patients and 73,216 3D dense displacement fields from finite element simulations of intraoperative prostate motion due to transrectal ultrasound probe pressure, the proposed models produced physically-plausible patient-specific motion of prostate glands. The ability to capture biomechanically simulated motion was evaluated using two errors representing generalisability and specificity of the model. The median values, calculated from a 10-fold cross-validation, were 2.8+/-0.3 mm and 1.7+/-0.1 mm, respectively. We conclude that the introduced approach demonstrates the feasibility of applying state-of-the-art machine learning algorithms to generate organ motion models from patient images, and shows significant promise for future research.

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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