Nonlinear Inverse Reconstruction for Real-Time MRI of the Human Heart Using Undersampled Radial FLASH

Martin Uecker¹, Shuo Zhang¹, Jens Frahm¹

A previously proposed algorithm for autocalibrated parallel imaging simultaneously estimates image content and coil sensitivities by inverting a nonlinear equation. Here, this algorithm is extended to non-Cartesian encodings and applied to real-time MRI. The method takes advantage of a convolution-based technique to simplify the implementation on a graphical processing unit (GPU) for reduced reconstruction times. The method is validated for real-time MRI of the human heart at 3 T using RF-spoiled radial FLASH. The results demonstrate artifact-free reconstructions for acquisitions with only 65 85 spokes corresponding to imaging times of 130 170 ms.