Prospective Head Motion Correction in T1- and T2-Weighted Long Echo Train Sequences Using Servo Navigation

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Neuroimaging
• Medical Physics

Background:

• Head motion is a significant challenge in structural MRI, leading to image artifacts and reduced diagnostic accuracy.
• Existing motion correction methods often have limitations in real-time application or effectiveness for certain motion types.

Purpose of the Study:

• To integrate MR-based servo navigation into MPRAGE and 3D-TSE sequences.
• To demonstrate the potential of servo navigation for prospective head motion correction in structural brain imaging.

Main Methods:

• Servo navigators were inserted before preparation pulses (before-prep) for efficient motion parameter estimation.
• Within-echo train correction (within-ET) was tested using reference navigators for frequent geometry updates.
• Methods were evaluated in instructed motion experiments and high-resolution 7T scans.

Main Results:

• Servo navigation significantly reduced artifacts from abrupt head motion in both MPRAGE and 3D-TSE sequences.
• Within-ET correction further mitigated residual artifacts from rapid in-train motion, particularly in MPRAGE.
• High-resolution scans showed preserved anatomical details, and image quality improved under involuntary motion during long acquisitions.

Conclusions:

• MR-based servo navigation offers accurate, real-time head motion correction for structural brain imaging.
• The developed servo navigation strategies enhance image quality and preserve anatomical details, even in challenging motion scenarios.