Overlap-Kernel EPI: Estimating MRI Shot-to-Shot Phase Variations by Shifted-Kernel Extraction From Overlap Regions at Arbitrary k-Space Locations.

ABSTRACT:

Purpose

In multi-shot EPI, shot-dependent phase fluctuations can introduce ghost artifacts, undermining advantages for enhancing resolution or reducing distortion, particularly in diffusion scans. Here, a novel self-navigation strategy based on shift-invariant kernel extraction is proposed, enabling robust estimation of phase inconsistencies from overlap bands at any k-space locations. It is inspired by RF sensitivity auto-calibration in parallel imaging, and extends traditional self-navigation trajectories beyond oversampled k-space center.

Theory and methods

Our shot-to-shot correction method only requires shot-to-shot sampling trajectories to slightly overlap at arbitrary k-space locations. Such k-space overlaps can be defined as shot-dependent auto-calibrating-signal reg

SUBMITTER: Tian R 

PROVIDER: S-EPMC12850564 | biostudies-literature | 2026 Apr

REPOSITORIES: biostudies-literature