Fast myocardial T1ρ mapping in mice using k-space weighted image contrast and a Bloch simulation-optimized radial sampling pattern.

Autor: Gram, Maximilian, Gensler, Daniel, Winter, Patrick, Seethaler, Michael, Arias-Loza, Paula Anahi, Oberberger, Johannes, Jakob, Peter Michael, Nordbeck, Peter
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Zdroj: MAGMA: Magnetic Resonance Materials in Physics, Biology & Medicine; Apr2022, Vol. 35 Issue 2, p325-340, 16p
Abstrakt: Purpose: T dispersion quantification can potentially be used as a cardiac magnetic resonance index for sensitive detection of myocardial fibrosis without the need of contrast agents. However, dispersion quantification is still a major challenge, because T mapping for different spin lock amplitudes is a very time consuming process. This study aims to develop a fast and accurate T mapping sequence, which paves the way to cardiac T dispersion quantification within the limited measurement time of an in vivo study in small animals. Methods: A radial spin lock sequence was developed using a Bloch simulation-optimized sampling pattern and a view-sharing method for image reconstruction. For validation, phantom measurements with a conventional sampling pattern and a gold standard sequence were compared to examine T quantification accuracy. The in vivo validation of T mapping was performed in N = 10 mice and in a reproduction study in a single animal, in which ten maps were acquired in direct succession. Finally, the feasibility of myocardial dispersion quantification was tested in one animal. Results: The Bloch simulation-based sampling shows considerably higher image quality as well as improved T quantification accuracy (+ 56%) and precision (+ 49%) compared to conventional sampling. Compared to the gold standard sequence, a mean deviation of − 0.46 ± 1.84% was observed. The in vivo measurements proved high reproducibility of myocardial T mapping. The mean T in the left ventricle was 39.5 ± 1.2 ms for different animals and the maximum deviation was 2.1% in the successive measurements. The myocardial T dispersion slope, which was measured for the first time in one animal, could be determined to be 4.76 ± 0.23 ms/kHz. Conclusion: This new and fast T quantification technique enables high-resolution myocardial T mapping and even dispersion quantification within the limited time of an in vivo study and could, therefore, be a reliable tool for improved tissue characterization. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index