This project implements a new image reconstruction algorithm for spiral MRI scans. Data is acquired in k-space on a variable-density spiral trajectory and regridded to a multiresolution hexagonal lattice, which preserves the inherent isotropic response of the spiral. A generalization of the one-dimensional Cooley-Tukey fast Fourier transform (FFT) algorithm for multidimensional signals periodic on arbitrary lattices is applied to efficiently reconstruct the data in image space.{09}The possibility for increased computational savings by exploiting the variable-density hexagonal grid is also presented. |