Normal T1, T2, T2* and extracellular volume reference values in healthy volunteers at 3 Tesla cardiac magnetic resonance

Roy, Clotilde [UCL] Slimani, Alisson [UCL] Amzulescu, Mihaela Silvia [UCL] Pasquet, Agnes [UCL] Vancraeynest, David [UCL] Vanoverschelde, Jean-Louis [UCL] Gerber, Bernhard [UCL] Pouleur, Anne-Catherine [UCL]

Myocardial T1, T2 and T2* imaging techniques become more and more used in clinical practice. While normal values for T1, T2 and T2* times are well established for 1.5 Tesla (T) cardiac magnetic resonance (CMR), data for 3T remain scarce. Therefore we sought to determine normal reference values and inter and intraobserver reproducibility for native T1, T2, T2* mapping and extracellular volume (ECV) at 3T in healthy volunteers. 55 healthy volunteers aged 20 to 80 years old (mean age = 50±17 years, 62% men) underwent left-ventricular T1 (11 images, 18 heart-beats 3-(3)-3-(3)-5 steady state free precession Modified Look Locker Imaging (MOLLI)), T2 (spin echo-imaging with 8 echos ranging from 8 to 64ms) and T2 * (gradient echo imaging with 8 echos ranging from 2.5 to 15 ms) mapping at 3T CMR (Philips Ingenia 3T). T1 mapping by MOLLI was repeated 15 min after administration of 0.2 mmol/kg Gadovist . ECV was computed as = (1-Ht)* ((1/T1) myo-post – (1/T1) myo-pre)/ (1/T1) blood-post – (1/T1) blood-pre). T1, T2 and T2* times and ECV were measured by 2 observers in a region of interest (ROI) encompassing the whole mid-ventricular short axis slice as well as in a septal ROI . Inter- and intraobserver reproducibility were estimated by intraclass correlation coefficient (ICC). We provide normal myocardial T2, T2*,T1 and ECV reference values for 3T CMR. Myocardial T2, T2* and T1 had high inter and intraobserver reproducibility and were significantly different from those reported at 1.5 Tesla CMR. By contrast, ECV values in the whole myocardium were not significantly different from those reported at 1.5 T.