Combined outer volume suppression and T2 preparation sequence for coronary angiography

Area of Science:

• Magnetic Resonance Imaging
• Cardiovascular Imaging
• Biomedical Engineering

Background:

• Coronary magnetic resonance angiography (MRA) is crucial for diagnosing heart conditions.
• Current MRA techniques can be limited by surrounding tissue signals and artifacts.
• Simultaneous outer volume suppression (OVS) and T2 weighting can improve image quality and reduce scan times.

Purpose of the Study:

• To develop and evaluate a novel magnetization preparation sequence for simultaneous OVS and T2 weighting in whole-heart coronary MRA.
• To enhance the efficiency and diagnostic accuracy of coronary MRA.

Main Methods:

• A combined OVS and T2 preparation sequence (OVS-T2 Prep) was designed using adiabatic pulses and a 2D spiral pulse.
• The sequence preserves magnetization within an elliptical cylinder while saturating magnetization outside.
• Performance was assessed using phantom studies and in vivo imaging on 13 healthy subjects with 3D cones trajectories.

Main Results:

• Phantom studies demonstrated expected T2-dependent signal amplitude and suppression in the spatial stopband.
• In vivo studies showed a passband-to-stopband signal ratio of 3.18 ± 0.77.
• The sequence significantly improved blood-myocardium contrast-to-noise ratio (1.43 ± 0.20, P < 0.001) and suppressed aliasing artifacts.

Conclusions:

• The OVS-T2 Prep sequence is effective for simultaneous outer volume suppression and T2 weighting.
• This compact sequence accelerates coronary MRA by reducing surrounding tissue signals and enhancing blood-myocardium contrast.
• The developed sequence holds promise for improving the clinical utility of coronary MRA.