Fig. 5
From: Adaptive Volterra Filter for Parallel MRI Reconstruction
Brain images reconstructed with different number of the second-order terms from the same data set in Fig. 3. a A reference image with SoS reconstruction of fully sampled data. b–g Reconstructed images using AV-GRAPPA with different numbers of the second-order terms. They are 1 time, 3 times, 5 times, 11 times, 17 times, and 21 times of the number of the original linear terms. When the less number of the second-order terms is used, noise cannot be suppressed completely. On the other hand, when the more number of the second-order terms is used, noise is removed but aliasing artifacts are appearing. Therefore, the number in the middle range can help produce high-quality reconstructed image