Self-calibrated trajectory estimation and signal correction method for robust radial imaging using GRAPPA operator gridding.

ABSTRACT:

Purpose

In radial imaging, projections may become "miscentered" due to gradient errors such as delays and eddy currents. These errors may result in image artifacts and can disrupt the reliability of direct current (DC) navigation. The proposed parallel imaging-based technique retrospectively estimates trajectory error from miscentered radial data without extra acquisitions, hardware, or sequence modification.

Theory and methods

After phase correction, self-calibrated GRAPPA operator gridding (GROG) weights are iteratively applied to shift-miscentered projections toward the center of k-space. A search algorithm identifies the shift that aligns the peak k-space signals by maximizing the sum-of-squares DC signal estimate of each projection. The algorithm returns a trajectory es

SUBMITTER: Deshmane A 

PROVIDER: S-EPMC4567526 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature