Free-breathing cine MRI.

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Biomedical Engineering

Background:

• Standard cardiac MRI cine exams require breath-holding, limiting patient tolerance and introducing motion artifacts.
• Breathing motion is a significant challenge in acquiring high-quality cardiac magnetic resonance imaging (MRI) cine sequences.

Purpose of the Study:

• To develop and validate a method for measuring and correcting respiratory motion during free-breathing cardiac cine MRI.
• To enable accurate assessment of cardiac function without the need for breath-holding.

Main Methods:

• Utilized real-time MRI to measure cardiac respiratory motion, including translations, rotations, and shears.
• Corrected motion in the k-space domain before gated-segmented reconstruction.
• Employed respiratory gating for data rejection to handle through-plane motion and complex deformations.
• Used a radial k-space trajectory for direct reconstruction of undersampled real-time images.

Main Results:

• Free-breathing corrected cardiac MRI achieved a sharpness of 0.38 +/- 0.04 mm⁻¹, significantly higher than uncorrected free-breathing scans (0.23 +/- 0.04 mm⁻¹).
• Clinical scoring rated corrected free-breathing images at 4.2 +/- 0.4, approaching the quality of breath-hold images (4.7 +/- 0.5).
• The developed method demonstrated substantial improvement over uncorrected free-breathing scans (2.2 +/- 0.5).

Conclusions:

• The developed method effectively measures and corrects respiratory motion in cardiac MRI.
• This technique allows for accurate cardiac function assessment during free-breathing, overcoming a major limitation of current MRI methods.
• The approach holds promise for improving patient experience and image quality in cardiac MRI.