Motion guidance lines for robust data consistency-based retrospective motion correction in 2D and 3D MRI

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Imaging
• Image Reconstruction

Background:

• Motion artifacts are a significant challenge in brain MRI, degrading image quality and diagnostic accuracy.
• Existing retrospective motion correction methods can be complex and time-consuming, limiting clinical applicability.

Purpose of the Study:

• To develop a robust retrospective motion-correction technique using repeating k-space guidance lines.
• To improve motion correction in Cartesian 2D and 3D brain MRI sequences.

Main Methods:

• Motion guidance lines were integrated into standard 2D turbo spin echo and 3D MPRAGE sequences.
• A data consistency-based approach informed motion estimation and reconstruction, guided by a low-resolution scout.
• Guidance lines were repeated during echo trains and discarded in final reconstruction.

Main Results:

• Simulations and in vivo experiments demonstrated accurate motion estimation and correction with 2 or 4 optimized guidance lines per shot.
• Clinically acceptable reconstruction times (approximately 1 second per shot) were achieved using standard GPU hardware.
• The method ensures expected image quality and contrast compatible with standard sequences.

Conclusions:

• The addition of guidance lines to scout-accelerated motion estimation enables robust retrospective motion correction.
• This technique can be effectively implemented without perturbing standard clinical MRI protocols and workflows.
• The method offers a practical solution for enhancing the reliability of brain MRI.