Accelerated real-time cine and flow under in-magnet staged exercise

Area of Science:

• Cardiovascular imaging
• Magnetic resonance imaging
• Exercise physiology

Background:

• Cardiovascular magnetic resonance (CMR) is vital for cardiac diagnosis.
• Exercise CMR (ExCMR) enhances diagnostic capabilities.
• Quantitative ExCMR faces challenges with motion and resolution.

Purpose of the Study:

• To assess biventricular function and hemodynamics using real-time ExCMR.
• To evaluate techniques for improving ExCMR image quality and repeatability.
• To demonstrate clinical feasibility of RT ExCMR.

Main Methods:

• Utilized high acceleration rates and coil reweighting to reduce motion artifacts.
• Applied end-expiratory beat selection to minimize respiratory motion impact.
• Conducted a staged exercise protocol in 24 healthy volunteers and 6 patients.

Main Results:

• Observed decreased end-systolic volume and stable end-diastolic volume with increasing exercise intensity.
• Demonstrated improved repeatability of cardiac function parameters with end-expiratory beat selection.
• Confirmed effective minimization of motion artifacts using coil reweighting, validated by image quality assessments.

Conclusions:

• Real-time ExCMR with in-magnet exercise is feasible in healthy subjects and patients.
• High acceleration, coil reweighting, and respiratory phase selection enhance ExCMR image quality.
• These techniques improve the repeatability of quantitative real-time ExCMR.