Coronary Flow Assessment Using Accelerated 4D Flow MRI With Respiratory Motion Correction.

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Biomedical Engineering

Background:

• Magnetic resonance imaging (MRI) shows promise for non-invasive screening of obstructive coronary artery disease in stable angina.
• Current MRI coronary blood flow quantification is limited to 2D techniques, restricting clinical utility.

Purpose of the Study:

• To develop and assess a framework for accelerated 4D flow MRI with respiratory motion correction and compressed sensing for coronary blood flow quantification.
• To investigate the feasibility and scan-rescan repeatability of this 4D flow MRI technique in healthy subjects.

Main Methods:

• Fourteen healthy subjects underwent 8x-accelerated 4D flow MRI of the left coronary artery (LCA) at 1.0 mm³ isotropic resolution.
• Respiratory motion correction utilized lung-liver navigators, real-time motion tracking, and rigid image registration.
• Diastolic LCA flow, VMAX, and VPEAK were quantified and compared to 2D flow MRI using concordance correlation coefficient (CCC) and coefficient of variation (CV).

Main Results:

• The protocol was successful in 11/14 subjects; 3 were excluded.
• 4D flow MRI demonstrated good scan-rescan repeatability for diastolic LCA flow (CCC/CV = 0.79/20.4%).
• Repeatability was moderate for VMAX (CCC/CV = 0.52/19.0%) and VPEAK (CCC/CV = 0.68/23.0%). Diastolic LCA flow agreed well with 2D MRI (CCC/CV = 0.75/20.1%).

Conclusions:

• Accelerated 4D flow MRI with respiratory motion correction and compressed sensing allows for repeatable diastolic LCA flow quantification.
• The technique shows good agreement with conventional 2D flow MRI, suggesting potential for improved clinical assessment of coronary artery disease.