Simultaneous high-resolution cardiac T1 mapping and cine imaging using model-based iterative image reconstruction

Abstract

Purpose: To provide high-resolution cardiac T₁ mapping of various cardiac phases and cine imaging within a single breath-hold using continuous golden ratio-based radial acquisition and model-based iterative image reconstruction.

Methods: Data acquisition was performed continuously using golden ratio-based radial sampling and multiple inversion pulses were applied independent of the heart rate. Native T₁ maps of diastole and systole were reconstructed with in-plane resolution of 1.3 × 1.3 mm² using model-based iterative image reconstruction. Cine images with 30 cardiac phases were reconstructed from the same data using kt-SENSE. The method was evaluated in a commercially available T₁ phantom and 10 healthy subjects. In vivo T₁ assessment was carried out segment-wise.

Results: Evaluation in the phantom demonstrated accurate T₁ times (R² > 0.99) and insensitivity to the heart rate. In vivo T₁ values did not differ between systole and diastole, and T₁ times assessed by the proposed approach were longer than measured with a modified Look-Locker inversion recovery (MOLLI) sequence, except for lateral segments. Cine images had a consistent dark-blood contrast and functional assessment was in agreement with assessment based on Cartesian cine scans (difference in ejection fraction: 0.26 ± 2.65%, P = 0.65).

Conclusion: The proposed approach provides native T₁ maps of diastole and systole with high spatial resolution and cine images simultaneously within 16 s, which could strongly improve the scan efficiency.

Keywords: T1 mapping; cine imaging; model-based reconstruction; multiparametric acquisition; myocardial tissue characterization.