Co-VeGAN: Complex-Valued Generative Adversarial Network for Compressive Sensing MR Image Reconstruction

Compressive sensing (CS) is widely used to reduce the image acquisition time of magnetic resonance imaging (MRI). Though CS based undersampling has numerous benefits, like high quality images with less motion artefacts, low storage requirement, etc., the reconstruction of the image from the CS-undersampled data is an ill-posed inverse problem which requires extensive computation and resources. In this paper, we propose a novel deep network that can process complex-valued input to perform high-quality reconstruction. Our model is based on generative adversarial network (GAN) that uses residual-in-residual dense blocks in a modified U-net generator with patch based discriminator. We introduce a wavelet based loss in the complex GAN model for better reconstruction quality. Extensive analyses on different datasets demonstrate that the proposed model significantly outperforms the existing CS reconstruction techniques in terms of peak signal-to-noise ratio and structural similarity index.

Robust Compressive Sensing MRI Reconstruction using Generative Adversarial Networks

Compressive sensing magnetic resonance imaging (CS-MRI) accelerates the acquisition of MR images by breaking the Nyquist sampling limit. In this work, a novel generative adversarial network (GAN) based framework for CS-MRI reconstruction is proposed. Leveraging a combination of patchGAN discriminator and structural similarity index based loss, our model focuses on preserving high frequency content as well as fine textural details in the reconstructed image. Dense and residual connections have been incorporated in a U-net based generator architecture to allow easier transfer of information as well as variable network length. We show that our algorithm outperforms state-of-the-art methods in terms of quality of reconstruction and robustness to noise. Also, the reconstruction time, which is of the order of milliseconds, makes it highly suitable for real-time clinical use.