Free-breathing myocardial perfusion MRI using SW-CG-HYPR and motion correction

Area of Science:

• Cardiovascular MRI
• Medical Imaging
• Image Reconstruction

Background:

• First-pass perfusion MRI is crucial for diagnosing ischemic heart disease.
• Current Sliding Window (SW) conjugate-gradient (CG) highly constrained back-projection reconstruction (HYPR) (SW-CG-HYPR) techniques require breath-holding due to respiratory motion sensitivity.
• Free-breathing MRI is desirable for patient comfort and accessibility.

Purpose of the Study:

• To develop and validate a non-model-based motion correction method for free-breathing myocardial perfusion MRI.
• To integrate this motion correction with SW-CG-HYPR to maintain high image quality without breath-holding.
• To assess the feasibility and performance of free-breathing SW-CG-HYPR myocardial MRI.

Main Methods:

• Developed a non-model-based motion correction algorithm for free-breathing cardiac MRI.
• Combined the motion correction with SW-CG-HYPR for myocardial perfusion imaging.
• Validated the method using simulations and in vivo studies on six healthy volunteers.

Main Results:

• Simulations confirmed the motion correction's effectiveness and independence from respiratory motion patterns.
• Free-breathing perfusion images with motion correction achieved significantly higher image quality scores (3.11 ± 0.34) compared to those without (2.27 ± 0.32).
• Image quality was comparable to breath-hold scans (3.12 ± 0.38), with high correlation (0.9764) in myocardial signal changes and agreement shown by Bland-Altman analysis.

Conclusions:

• The proposed non-model-based motion correction effectively enables free-breathing myocardial perfusion MRI using SW-CG-HYPR.
• This technique significantly improves image quality over uncorrected free-breathing scans and matches breath-hold performance.
• This advancement offers a promising approach for more accessible and comfortable myocardial perfusion MRI.