Guanhua Wang1, Douglas C. Noll1, and Jeffrey A. Fessler2
1Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States, 2Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States
1Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States, 2Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States
Fast approximation method for calculating the Jacobian matrix of the NUFFT operations.
Figure 3. The learned trajectories by different methods. The initialization is an under-sampled radial sampling pattern.
Figure 1. The gradient w.r.t. $$$\boldsymbol{x}$$$. We denote auto-differentiation of NUFFT as auto-diff, exact NDFT as exact, and our approximation method as approx. Three calculation methods achieve similar results.