Meeting Banner
Abstract #3785

Robust Estimation of True K-Space Center Position for Radial Center-Out Trajectories

Martin Krmer1, Karl-Heinz Herrmann1, Jrgen R. Reichenbach1

1Medical Physics Group, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany

Radial center-out trajectories are extremely sensitive towards imperfections in the gradient and data sampling hardware. Even the smallest jitter between data sampling and gradient onset must be compensated during image reconstruction in order to obtain images free of delay artifacts. We propose to estimate such delays with a template scan using a very short additional dephaser. The delay is given from the difference between the expected k-space center position along the template readouts and the actual center crossing. We shot that a very robust estimation of the true k-space center crossing can be made by analyzing k-space phase directly.

Abstract PDF Presentation Video

Keywords

accuracy accurate achieve acquisition activity actual additional affected allowing amplitude analytically analyze analyzed analyzing application approximately artifacts audience avoid ball becoming black blue challenging clear clinical compensated compromise contrary corrected correcting correction corresponds crossing crucial dashed dead degraded delay delays delineates depends describe deviation diagnostic digital directly distinct dwell eddy effective enlarged ensure ensuring especially estimation even evenly exact expected extracting fast filter filtering final finding fixed forms free functions gradient gradients grid grids hardware highly immediately imperfections implementation implemented important improved increasingly interval iterative jitter knot known lead linear magnitude makes matrix measured measures minimal next node occurs optimized oversampling peters phantom physics played portion position precision predict problem pulse radial radiology ramp rather readout readouts real reconstruction repetition respectively rotated sampled sampling searched severely short shorten simple since slice smallest space spatially spokes squared start starting structure switched system systems target template timings trajectories trio true varying vicinity wide