Meeting Banner
Abstract #2542

GRAPPA Operator Shift Correction for Non-Cartesian Imaging Trajectories

Anagha Deshmane1, Nicole Seiberlich1, Jeffrey Duerk1, 2, Mark A. Griswold1, 2

1Dept. of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; 2Dept. of Radiology, University Hospitals of Cleveland, Cleveland, OH, United States

Gradient timing delays can cause deviations from the ideal trajectory in non-Cartesian imaging. The proposed method aims to correct for trajectory errors and determine the signal at the center of k-space. Paths between points acquired along mis-centered radial projections and the true center of k-space are traced by a gradient ascent algorithm which iteratively applies a GRAPPA operator to shift k-space data while continually evaluating an estimate of the echo peak signal. This method can be used to perform trajectory measurement without field monitoring or extra acquisitions, and signal at the true k-space center can be used for retrospective self-gated imaging.