Clinical feasibility of 3D-QALAS - Single breath-hold 3D myocardial T1 and T2-mapping

Purpose: To investigate the in-vivo precision and clinical feasibility of 3D-QALAS- a novel method for simultaneous three-dimensional myocardial T1- and T2-mapping. Methods: Ten healthy subjects and 23 patients with different cardiac pathologies underwent cardiovascular 3 T MRI examinations including 3D-QALAS, MOLLI and T2-GraSE acquisitions. Precision was investigated in the healthy subjects between independent scans, between dependent scans and as standard deviation of consecutive scans. Clinical feasibility of 3D-QALAS was investigated for native and contrast enhanced myocardium in patients. Data were analyzed using mean value and 95% confidence interval, Pearson correlation, Paired t-tests, intraclass correlation and Bland-Altman analysis. Results: Average myocardial relaxation time values and SD from eight repeated acquisitions within the group of healthy subjects were 1178 +/- 18.5 ms (1.6%) for T1 with 3D-QALAS, 52.7 +/- 1.2 ms (23%) for T2 with 3D-QALAS, 1145 +/- 10.0 ms (0.9%) for Tl with MOLLI and 49.2 +/- 0.8 ms (1.6%) for T2 with GraSE. Myocardial Tl and T2 relaxation times obtained with 3D-QALAS correlated very well with reference methods; MOW for T1 (r = 0.994) and T2-GraSE for T2 (r = 0.818) in the 23 patients. Average native/post-contrast myocardial Tl values from the patients were 1166.2 ms/411.8 ms for 3D-QALAS and 1174.4 ms/438.9 ms for MOW. Average native myocardial T2 values from the patients were 53.2 ms for 3D-QAIAS and 54.4 ms for T2-GraSE. Conclusions: Repeated independent and dependent scans together with the intra-scan repeatability, demonstrated all a very good precision for the 3D-QALAS method in healthy volunteers. This study shows that 3D T1 and T2 mapping in the left ventricle is feasible in one breath hold for patients with different cardiac pathologies using 3D-QALAS. (C) 2016 Elsevier Inc. All rights reserved.Funding Agencies|Swedish Heart-Lung Foundation [20120449, 20140398]; Swedish Research Council [2014-6191]