Whole-brain T₂ mapping with radial sampling and retrospective motion correction at 3T.

Area of Science:

• Magnetic Resonance Imaging
• Quantitative MRI
• Neuroimaging

Background:

• Whole-brain T2 mapping is valuable but limited by long scan times and motion artifacts.
• Patient discomfort and data corruption hinder routine clinical application of T2 mapping.
• Developing faster, motion-robust T2 mapping is crucial for broader clinical adoption.

Purpose of the Study:

• To investigate a method for accurate whole-brain T2 mapping within a limited acquisition time.
• To develop and evaluate motion correction capabilities for T2 mapping sequences.
• To address the challenges of scan time and motion in routine T2 mapping.

Main Methods:

• Implemented a 3D radial multi-echo spin-echo sequence with optimized sampling.
• Estimated and corrected for intra-scan motion using a retrospective approach.
• Utilized linear subspace constrained reconstruction for motion-corrected image reconstruction.

Main Results:

• Achieved whole-brain T2 mapping in under 7 minutes, successfully depicting white matter lesions.
• Demonstrated significant reduction in T2 estimation errors in motion-corrupted data, particularly for pediatric patient motion.
• Showed substantial improvement in T2 maps at both voxel and structural levels after retrospective motion correction.

Conclusions:

• A novel whole-brain T2 mapping sequence with retrospective intra-scan motion correction is presented.
• The method achieves reasonable acquisition times without additional hardware or navigators.
• Advanced iterative reconstruction is required, but the approach enhances T2 mapping reliability.