3D Through-Time Radial GRAPPA with In-Plane and Through-Plane Acceleration

Jesse I. Hamilton¹, Katherine L. Wright¹, Kestutis Barkauskas¹, Vikas Gulani², Nicole Seiberlich¹

Previous work has shown that through-time non-Cartesian GRAPPA can reconstruct images with high radial acceleration factors. Here we demonstrate that 3D through-time radial GRAPPA can reconstruct data accelerated not only in-plane but also through-plane to yield high spatiotemporal resolutions. Reconstruction was performed with a 3D kernel, and calibration data were amassed using fully-sampled data and repeating the kernel through-k-space, through-time, and through-partitions to calculate accurate non-Cartesian GRAPPA weights. Time-resolved renal MR angiography data with total acceleration R=12 (R=6 in-plane, R=2 through-plane) were reconstructed at 1.45x1.45x3.00 mm³ spatial resolution and 2 s/frame temporal resolution (after retrospectively undersampling partitions).