Simultaneous multislice imaging for native myocardial T₁ mapping: Improved spatial coverage in a single breath-hold.

Area of Science:

• Cardiovascular Magnetic Resonance Imaging
• Quantitative MRI Techniques
• Myocardial Tissue Characterization

Background:

• T1 mapping is crucial for assessing myocardial tissue characteristics.
• Current T1 mapping methods can be time-consuming, limiting clinical application.
• Accelerated imaging techniques are needed to improve efficiency and patient comfort.

Purpose of the Study:

• To develop and evaluate a simultaneous multislice saturation recovery myocardial T1 mapping method.
• To assess the feasibility of single-breath-hold T1 quantification across multiple slices.
• To compare different multiband reconstruction methods for accuracy and image quality.

Main Methods:

• Implementation of saturation pulse-prepared heart rate independent inversion recovery (SAPPHIRE) T1 mapping with simultaneous multislice FLASH imaging.
• Utilized controlled aliasing in parallel imaging (CAIPI) for noise reduction across three slices.
• Compared Slice- and in-plane GRAPPA, CG-SENSE, and Tikhonov-regularized CG-SENSE reconstruction methods against single-band T1 mapping in phantoms and healthy subjects.

Main Results:

• Multiband T1 mapping showed good agreement with single-band methods (NRMSE <1.0%) in phantoms.
• In vivo T1 measurements were comparable between multiband and single-band acquisitions (P=0.86).
• GRAPPA reconstruction exhibited the lowest spatial variability (1.29-fold increase) and interslice leakage (5.4%) compared to CG-SENSE methods.

Conclusions:

• Simultaneous multislice myocardial T1 mapping enables efficient, single-breath-hold T1 quantification.
• GRAPPA-based reconstruction offers the best performance in terms of homogeneity and minimal interslice leakage.
• This accelerated technique holds potential for routine clinical use in cardiac MRI.