Inherent correction of motion-induced phase errors in multishot spiral diffusion-weighted imaging

Area of Science:

• Medical Imaging
• Neuroimaging
• Biophysics

Background:

• Multishot spiral imaging offers high-resolution diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) as an alternative to echo-planar imaging.
• Subject motion during diffusion-weighting gradients induces phase inconsistencies, leading to signal loss and aliasing artifacts in reconstructed images.
• Existing artifact reduction methods, like variable-density trajectories or navigator echoes, necessitate longer scan times.

Purpose of the Study:

• To propose and evaluate a novel iterative phase correction method for multishot spiral DWI.
• To address motion-induced phase errors without extending acquisition duration.
• To demonstrate the efficacy of the proposed method in correcting rigid-body motion artifacts.

Main Methods:

• Development of an iterative phase correction algorithm.
• Implementation of numerical simulations to model motion-induced phase errors.
• In vivo experiments on human brain diffusion-weighted imaging using multishot spiral trajectories.

Main Results:

• The proposed iterative method effectively corrects spatially linear phase errors caused by rigid-body motion.
• Demonstrated reduction in signal loss and aliasing artifacts in reconstructed images.
• Validation through both numerical simulations and in vivo human brain data.

Conclusions:

• The novel iterative phase correction method is an efficient and effective solution for motion artifacts in multishot spiral DWI.
• This technique eliminates the need for additional scan time, making high-resolution diffusion imaging more robust.
• The method shows significant potential for improving the quality of neuroimaging studies utilizing multishot spiral sequences.