Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada.
Department of Medical Biophysics, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada.
Magn Reson Med. 2019 Sep;82(3):901-910. doi: 10.1002/mrm.27772. Epub 2019 Apr 22.
Subject motion in MRI remains an unsolved problem; motion during image acquisition may cause blurring and artifacts that severely degrade image quality. In this work, we approach motion correction as an image-to-image translation problem, which refers to the approach of training a deep neural network to predict an image in 1 domain from an image in another domain. Specifically, the purpose of this work was to develop and train a conditional generative adversarial network to predict artifact-free brain images from motion-corrupted data.
An open source MRI data set comprising T *-weighted, FLASH magnitude, and phase brain images for 53 patients was used to generate complex image data for motion simulation. To simulate rigid motion, rotations and translations were applied to the image data based on randomly generated motion profiles. A conditional generative adversarial network, comprising a generator and discriminator networks, was trained using the motion-corrupted and corresponding ground truth (original) images as training pairs.
The images predicted by the conditional generative adversarial network have improved image quality compared to the motion-corrupted images. The mean absolute error between the motion-corrupted and ground-truth images of the test set was 16.4% of the image mean value, whereas the mean absolute error between the conditional generative adversarial network-predicted and ground-truth images was 10.8% The network output also demonstrated improved peak SNR and structural similarity index for all test-set images.
The images predicted by the conditional generative adversarial network have quantitatively and qualitatively improved image quality compared to the motion-corrupted images.
磁共振成像中的受试者运动仍然是一个未解决的问题;图像采集过程中的运动可能会导致模糊和伪影,从而严重降低图像质量。在这项工作中,我们将运动校正视为图像到图像的翻译问题,这是指通过训练深度神经网络来预测一个域中的图像从另一个域中的图像。具体来说,这项工作的目的是开发和训练一个条件生成对抗网络,以从运动伪影数据中预测无伪影的大脑图像。
使用包含 53 名患者的 T*-加权、FLASH 幅度和相位脑图像的开源 MRI 数据集来生成用于运动模拟的复杂图像数据。为了模拟刚性运动,根据随机生成的运动曲线对图像数据进行旋转和平移。使用运动伪影和相应的地面真实(原始)图像作为训练对来训练条件生成对抗网络,包括生成器和鉴别器网络。
与运动伪影图像相比,条件生成对抗网络预测的图像具有更高的图像质量。测试集图像中运动伪影和地面真实图像之间的平均绝对误差为图像平均值的 16.4%,而条件生成对抗网络预测的和地面真实图像之间的平均绝对误差为 10.8%。网络输出还显示出所有测试集图像的峰值信噪比和结构相似性指数均有所提高。
与运动伪影图像相比,条件生成对抗网络预测的图像在图像质量方面具有定量和定性的提高。