Motion robust high resolution 3D free-breathing pulmonary MRI using dynamic 3D image self-navigator.

Area of Science:

• Medical Imaging
• Magnetic Resonance Imaging
• Pulmonary Medicine

Background:

• Free-breathing pulmonary MRI is challenging due to respiratory motion.
• High-resolution imaging is crucial for detecting pulmonary pathologies.
• Existing motion compensation techniques have limitations.

Purpose of the Study:

• To develop a motion robust, high-resolution 3D free-breathing pulmonary MRI technique.
• To utilize a novel dynamic 3D image navigator derived from imaging data.
• To improve image quality and motion compensation in pulmonary MRI.

Main Methods:

• Acquired 5-minute free-breathing scans using a 3D ultrashort echo time (UTE) sequence with 1.25 mm isotropic resolution.
• Reconstructed dynamic 3D self-navigating images under locally low rank (LLR) constraints for motion compensation.
• Employed soft-gating and respiratory motion-resolved techniques for motion compensation.

Main Results:

• Successfully estimated complex respiratory motion patterns using the dynamic 3D self-navigator (7.5 mm isotropic resolution, 300 ms temporal resolution).
• Achieved improved image quality compared to respiratory belt and DC-based navigators.
• Demonstrated good image quality from highly undersampled data in volunteers and patients using motion compensation techniques.

Conclusions:

• An optimized 3D UTE sequence with proposed reconstruction methods yields high-resolution, motion-robust pulmonary MRI.
• The approach is feasible in patients with irregular breathing, depicting clinically relevant pulmonary pathologies.
• This technique enhances the diagnostic capability of pulmonary MRI.