Comparison of native myocardial T1 and T2 mapping at 1.5T and 3T in healthy volunteers

Abstract

Summary Background Myocardial native T1 and T2 mapping are promising techniques for quantitative assessment of diffuse myocardial pathologies; however, due to conflicting data regarding normal values, routine clinical implementation of this method is still challenging. Methods To evaluate this situation during daily clinical practice the characteristics of normal values obtained in 60 healthy volunteers who underwent magnetic resonance imaging (MRI) scans on 1.5T and 3T scanners were studied. The T1 modified look-locker inversion recovery (MOLLI; 5(3)3; modified for higher heart rates) and T2 navigator gated black-blood prepared gradient-spin-echo (GraSE) sequences were used. Results While age and body mass index did not affect relaxation times, a gender and heart rate dependency was found showing higher T1 and T2 values in females, whereas at higher heart rates a prolongation of T1 and a shortening of T2 relaxation times was found. Particularly prone to artifacts were T2 measurements at 3T and the inferolateral wall. In the individual setting mean relaxation times for T1 were 995.8 ± 30.9 ms at 1.5T and 1183.8 ± 37.5 ms at 3T and 55.8 ± 2.8 ms at 1.5T and 51.6 ± 3 ms at 3T for T2 indicating a high dependency of reference values on MRI protocol when compared to the literature. Furthermore, as presumed mean T1 and T2 values correlated in the same individual. Conclusions The T1 and T2 relaxation times depend on physiological factors and especially on MRI protocols. Therefore, reference values should be validated individually in every radiological institution before implementing mapping protocols in daily clinical practice. Correlation of mean T1 and T2 values in the same proband at both field strengths indicates intraindividual reproducibility.

Normal values of native T1 and T2 relaxation times on 3T cardiac MR in a healthy pediatric population aged 9–18 years

“…7 Native T 1 reference values are higher for 3T than 1.5T scanners 10,11 and depend on the scanning sequence used with highest values for SASHA and lowest for ShMOLLI, with the MOLLI technique (as used in this study) in between. Some studies did not find any difference in native T 1 relaxation time according to sex 3,17 or age, 3,16 while others reported that age influenced T 1 values only in females. 14,16 There is, however, a large discrepancy between the results of those studies, which can be influenced by the type of sequence and scanner used.…”

“…Some studies did not find any difference in native T 1 relaxation time according to sex 3,17 or age, 3,16 while others reported that age influenced T 1 values only in females. 16 Until now, it was unknown whether pubertal status could influence T 1 and T 2 relaxation times. 17 Even less is known in relation to T 2 relaxation time values, which were reported to be higher in females, 16 to decrease with age, 13 and with lowering heart rate.…”

“…All of the reference values for T 1 and T 2 relaxation times presented before included only adult populations, reported mainly T 1 relaxation times and were performed mostly on 1.5T scanners. 14,16 There is, however, a large discrepancy between the results of those studies, which can be influenced by the type of sequence and scanner used. In adult populations native T 1 values were most commonly influenced by sex (higher in females), 10,[12][13][14][15]21 age (increase or decrease), 12,13,17 and heart rate.…”

“…14,16 There is, however, a large discrepancy between the results of those studies, which can be influenced by the type of sequence and scanner used. 17 Even less is known in relation to T 2 relaxation time values, which were reported to be higher in females, 16 to decrease with age, 13 and with lowering heart rate. 14,15 Also, the influence of heart rate has not been unequivocally reproduced.…”

“…1,9 Use of mapping techniques requires accurate knowledge of normal ranges. 3,4,[12][13][14][15][16][17] Therefore, the aim of our study was to present limited normal values of native T 1 and T 2 mapping relaxation times in healthy pediatric subjects of different age and sex. [10][11][12] In recent years, there have been reports presenting established normal values for T 1 and T 2 , but none of them included pediatric populations.…”