Three-dimensional high-isotropic-resolution MR fingerprinting optimized for 0.55 T.

Area of Science:

• Magnetic Resonance Imaging
• Quantitative Imaging
• Biomedical Engineering

Background:

• Low-field MRI (0.55T) presents challenges in signal-to-noise ratio and k-space acquisition speed.
• Quantitative imaging requires robust methods to overcome hardware limitations for diagnostic accuracy.

Purpose of the Study:

• To develop a rapid, high-resolution quantitative imaging approach for 0.55T MRI scanners.
• To address limitations in signal-to-noise ratio and gradient performance at lower field strengths.

Main Methods:

• Adapted 3D spiral projection imaging MR fingerprinting (MRF) for 0.55T scanners.
• Incorporated improved k-space sampling, optimized flip-angle patterns, gradient correction, attention-based denoising, and motion correction.

Main Results:

• Achieved high-quality 1.2-mm isotropic whole-brain and 1-mm isotropic knee quantitative maps.
• Acquisition time for both maps was reduced to 4.5 minutes.
• Validated the method in phantom, in vivo brain, and knee studies.

Conclusions:

• Novel methods and advanced techniques enabled high-isotropic-resolution MRF on a 0.55T scanner.
• Demonstrated enhanced efficiency, motion resilience, and quantitative accuracy in low-field MRI.
• This approach expands the utility of lower-field MRI systems for quantitative diagnostics.