Arrhythmia insensitive rapid cardiac T1 mapping: comparison to modified look locker inversion recovery T1 mapping in mit

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ORIGINAL PAPER

Arrhythmia insensitive rapid cardiac T1 mapping: comparison to modified look locker inversion recovery T1 mapping in mitral valve prolapse patients Ernest Cheung1   · Hui‑Chen Han1 · Emma Hornsey1 · Leonid Churilov2 · Kyung Pyo Hong4 · Julie Smith1 · Daniel Kim3 · Omar Farouque1,2 · Andrew Teh2,5 · Han Lim1,2 · Ruth P. Lim1,2 Received: 23 February 2020 / Accepted: 1 June 2020 © Springer Nature B.V. 2020

Abstract We compare a saturation recovery arrhythmia insensitive rapid (AIR) T1 mapping technique which is less sensitive to heart rate and requires shorter breath-holds to modified Look-Locker inversion recovery (MOLLI) T1 mapping in patients with mitral valve prolapse. 55 patients underwent AIR and MOLLI at 1.5 T. AIR and MOLLI-derived blood and myocardial T1 values and extracellular volume (ECV) were measured by two independent readers. T1 values and ECV from both techniques and inter-reader agreement were compared with Lin’s concordance correlation coefficient (LCC) and reduced major axis regression. T1 values were consistently overestimated for AIR compared to MOLLI and vice versa for ECV. In the mitral valve prolapse population, mean native and post contrast myocardial T1 value for MOLLI were 1000 ± 40 ms and 411.9 ± 44.2 ms respectively and 1090.6 ± 58.7 ms and 488.2 ± 45.7 ms for AIR. Mean native and post contrast blood T1 values for MOLLI were 1566.6 ± 72.3 ms and 276.6 ± 34.1 ms respectively versus 1657.2 ± 180.9 ms and 294.9 ± 35.6 ms for AIR. AIR underestimated ECV relative to MOLLI (23.5 ± 0.4% vs 27.7 ± 0.4%). We found excellent inter-reader agreement (LCC all > 0.94, p  0.97, p  10/hr) as recorded with 24 h Holter monitoring. Patient characteristics are summarized in Table 1.

Image acquisition MOLLI and AIR images were acquired with a 1.5-T wholebody scanner (Avanto; Siemens Healthcare, Erlangen Germany), with a 6-channel body phased array coil anteriorly and spine coils posteriorly automatically selected by the system. Mid-ventricular short axis MOLLI images were acquired pre-contrast and at 15 min after intravenous injection of 0.2 mmol/kg of gadoterate meglumine (Dotarem®, Aspen Pharmacare) with breath-holding at end expiration. 3 contiguous AIR slices were obtained at the same time points immediately following MOLLI, with the central slice identically matched to the MOLLI slice. T1-weighted and proton density images were acquired for AIR with T1 calculated from the ratio of both acquired sequences. Modified Look Locker inversion recovery was performed as described in previous studies, with five images after the first inversion, a pause of three heartbeats, and three images after the second inversion [19, 20]. Serum haemoglobin was measured in each patient on the day of scanning for ECV calculation. MRI parameters for AIR and MOLLI are summarized in Table 2.

The International Journal of Cardiovascular Imaging

Image analysis

Statistical analysis

T1 MOLLI maps were automatically generated by the scanner. After anonymization of all cases, T1 AIR maps were generated by one inves