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International Journal of Biomedical Imaging
Volume 2006, Article ID 87092, 9 pages

Improving Non-Cartesian MRI Reconstruction through Discontinuity Subtraction

1Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
2Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC 27710, USA

Received 30 April 2006; Revised 7 September 2006; Accepted 8 October 2006

Academic Editor: Tiange Zhuang

Copyright © 2006 Jiayu Song and Qing Huo Liu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Non-Cartesian sampling is widely used for fast magnetic resonance imaging (MRI). Accurate and fast image reconstruction from non-Cartesian k-space data becomes a challenge and gains a lot of attention. Images provided by conventional direct reconstruction methods usually bear ringing, streaking, and other leakage artifacts caused by discontinuous structures. In this paper, we tackle these problems by analyzing the principal point spread function (PSF) of non-Cartesian reconstruction and propose a leakage reduction reconstruction scheme based on discontinuity subtraction. Data fidelity in k-space is enforced during each iteration. Multidimensional nonuniform fast Fourier transform (NUFFT) algorithms are utilized to simulate the k-space samples as well as to reconstruct images. The proposed method is compared to the direct reconstruction method on computer-simulated phantoms and physical scans. Non-Cartesian sampling trajectories including 2D spiral, 2D and 3D radial trajectories are studied. The proposed method is found useful on reducing artifacts due to high image discontinuities. It also improves the quality of images reconstructed from undersampled data.