# Comprehensive three-dimensional free-breathing magnetic resonance imaging for simultaneous myocardial viability and coronary artery visualization at 1.5T and 3T

## TL;DR

This study introduces a new MRI technique that captures both heart tissue and coronary artery images simultaneously with high resolution and accuracy.

## Contribution

The novel GB-BOOST sequence enables co-registered 3D gray-blood PSIR and CMRA imaging in a single scan.

## Key findings

- GB-BOOST successfully acquired co-registered 3D PSIR and CMRA images in 23 patients with 1.2 mm³ resolution.
- The sequence showed comparable image contrast and quality to separately acquired 2D and 3D clinical sequences.
- It achieved 100% respiratory scan efficiency using free-breathing acquisition.

## Abstract

Cardiovascular magnetic resonance is promising for non-invasive assessment of various cardiac diseases with the ability to provide multi-contrast images, including late gadolinium enhancement (LGE) for myocardial tissue characterization and coronary magnetic resonance angiography (CMRA) for anatomical imaging. However, LGE and CMRA are usually acquired separately in clinical routine with unmatched spatial resolution and slice positions. In this proof of concept study, we aim to achieve a one-stop imaging of 3D gray-blood phase-sensitive inversion recovery (PSIR) LGE and 3D CMRA by proposing a free-breathing simultaneous Gray-Blood and Bright-blOOd phase SensiTive inversion recovery (GB-BOOST) sequence.

The proposed research sequence acquires two interleaved 3D volumes with inversion recovery and T2 preparation pulses to obtain gray-blood PSIR and CMRA, respectively. Two-dimensional image navigator (iNAV) is performed before the acquisition of each volume to detect respiratory motion, enabling free-breathing acquisition with 100% respiratory scan efficiency. The GB-BOOST framework is compatible with both Dixon gradient echo (GRE) and balanced steady-state free precession (bSSFP) sequences for the application at 3T and 1.5T. In-vivo validation experiments included in total 23 patients for GB-BOOST, which were performed on either a 3T or a 1.5T clinical scanner. The performance of the proposed sequence was compared with clinical 2D gray-blood PSIR and free-breathing 3D CMRA.

GB-BOOST was successfully performed on all 23 patients and was able to efficiently acquire intrinsically co-registered 3D PSIR and CMRA images with 1.2 mm3 resolution in 9.4 ± 1.3 min. Compared with 2D gray-blood PSIR, 3D PSIR GB-BOOST had comparable scar area detection performance without significant differences in image contrast of scar-to-blood (0.42 ± 0.40 vs. 0.30 ± 0.43, p = 0.38), scar-to-myocardium (1.09 ± 0.27 vs. 1.02 ± 0.32, p = 0.30), and blood-to-myocardium (0.67 ± 0.19 vs. 0.72 ± 0.23, p = 0.56). Compared with single-contrast 3D CMRA sequence, 3D T2prep GB-BOOST showed comparable image quality and quantitative vessel metrics of coronary arteries.

The proposed GB-BOOST sequence can achieve simultaneous co-registered 3D whole-heart gray-blood PSIR and CMRA in a single scan with image contrast and image quality comparable with separately acquired images.

ga1