AUTHOR=Jarkman Charlotta , Carlhäll Carl-Johan , Henningsson Markus 

TITLE=Clinical evaluation of the Multimapping technique for simultaneous myocardial T1 and T2 mapping

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2022.960403

DOI=10.3389/fcvm.2022.960403

ISSN=2297-055X

ABSTRACT=<p>The Multimapping technique was recently proposed for simultaneous myocardial T<sub>1</sub> and T<sub>2</sub> mapping. In this study, we evaluate its correlation with clinical reference mapping techniques in patients with a range of cardiovascular diseases (CVDs) and compare image quality and inter- and intra-observer repeatability. Multimapping consists of an ECG-triggered, 2D single-shot bSSFP readout with inversion recovery and T<sub>2</sub> preparation modules, acquired across 10 cardiac cycles. The sequence was implemented at 1.5T and compared to clinical reference mapping techniques, modified Look-Locker inversion recovery (MOLLI) and T<sub>2</sub> prepared bSSFP with four echo times (T<sub>2</sub>bSSFP), and compared in 47 patients with CVD (of which 44 were analyzed). In diseased myocardial segments (defined as the presence of late gadolinium enhancement), there was a high correlation between Multimapping and MOLLI for native myocardium T<sub>1</sub> (<italic>r</italic><sup>2</sup> = 0.73), ECV (r<sup>2</sup> = 0.91), and blood T<sub>1</sub> (r<sup>2</sup> = 0.88), and Multimapping and T<sub>2</sub>bSSFP for native myocardial T<sub>2</sub> (r<sup>2</sup> = 0.80). In healthy myocardial segments, a bias for native T<sub>1</sub> (Multimapping = 1,116 ± 21 ms, MOLLI = 1,002 ± 21, <italic>P</italic> &lt; 0.001), post-contrast T<sub>1</sub> (Multimapping = 479 ± 31 ms, MOLLI = 426 ± 27 ms, 0.001), ECV (Multimapping = 21.5 ± 1.9%, MOLLI = 23.7 ± 2.3%, <italic>P</italic> = 0.001), and native T<sub>2</sub> (Multimapping = 48.0 ± 3.0 ms, T<sub>2</sub>bSSFP = 53.9 ± 3.5 ms, <italic>P</italic> &lt; 0.001) was observed. The image quality for Multimapping was scored as higher for all mapping techniques (native T<sub>1</sub>, post-contrast T<sub>1</sub>, ECV, and T<sub>2</sub>bSSFP) compared to the clinical reference techniques. The inter- and intra-observer agreements were excellent (intraclass correlation coefficient, ICC &gt; 0.9) for most measurements, except for inter-observer repeatability of Multimapping native T<sub>1</sub> (ICC = 0.87), post-contrast T<sub>1</sub> (ICC = 0.73), and T<sub>2</sub>bSSFP native T<sub>2</sub> (ICC = 0.88). Multimapping shows high correlations with clinical reference mapping techniques for T<sub>1</sub>, T<sub>2</sub>, and ECV in a diverse cohort of patients with different cardiovascular diseases. Multimapping enables simultaneous T<sub>1</sub> and T<sub>2</sub> mapping and can be performed in a short breath-hold, with image quality superior to that of the clinical reference techniques.</p>