Native T1 and T2 reference values for maltese healthy cohort

Abstract

BackgroundCardiac Magnetic Resonance (CMR) is increasingly being used for diagnosing various cardiac conditions. Parametric mapping enables quantitative myocardial characterization by directly measuring myocardial T1 and T2 values. However, reference values of parametric mapping are not standardized across different vendors and scanners, causing drawbacks for clinical implementation of this technique across different sites. We assessed the reference ranges of native T1 and T2 values in a healthy Maltese cohort to establish a local parametric mapping service. Methods and ResultsHealthy subjects (n=51; mean age 36.0 [range 19-59] years) with normal cardiac function on CMR were recruited. Subjects underwent uniform parametric mapping pulse sequences (MOLLI 5(3)3 for native T1 mapping, and gradient echo single shot FLASH readout for T2 mapping) on a 3T Siemens MAGNETOM Vida scanner. Native T1 and T2 values were measured by placing a region of interest within the interventricular septum at midventricular level. Intra-and inter-observer variability were assessed using Bland-Altman plots. Normal distribution of data was assessed using Kolmogorov-Smirnov test (p-value of 0.773 for native T1, p-value of 0.125 for T2). Mean ±1.96 SD was used as a reference range. Mean native T1 and T2 values were 1200.1 ±30.7 ms and 39.5 ±1.8 ms, respectively. All parameters had excellent dayto-day intra-observer reproducibility and inter-observer reproducibility. ConclusionFor the rst time in Malta, we established the native T1 and T2 parametric mapping reference values for healthy Caucasian Maltese individuals. This will assist cardiologists to establish diagnosis, disease progression, and response to treatment of various myocardial diseases locally.

Multi-site comparison of parametric T1 and T2 mapping: healthy travelling volunteers in the Berlin research network for cardiovascular magnetic resonance (BER-CMR)

“…In accordance to missing data regarding T2 travelling volunteer studies, normative values for T2 mapping with a 3 T system and the FLASH sequence are sparse. The previously mentioned study by Yamagata et al used the same sequence at 3 T with mean values of 39.5 ± 1.8 ms, which is congruent to ranges in our sites [ 29 ]. In the same article one can find other smaller studies investigating T2 mapping which also yielded similar results [ 29 ].…”

“…The previously mentioned study by Yamagata et al used the same sequence at 3 T with mean values of 39.5 ± 1.8 ms, which is congruent to ranges in our sites [ 29 ]. In the same article one can find other smaller studies investigating T2 mapping which also yielded similar results [ 29 ]. A recent Meta-Analysis compared T2 times across different vendors and acquisition schemes, with a pooled mean of 46 ms at 3 T [ 34 ].…”

“…To provide further context and insight on the variability we will discuss studies with the same vendor and sequence design. As an example, Yamagata et al carried out a CMR mapping study in a cohort of 51 healthy subjects [ 29 ]. Acquisition schemes, vendor and field strength were similar as in our study, only with differences existing in scanner and post-processing approach [ 29 ].…”

“…As an example, Yamagata et al carried out a CMR mapping study in a cohort of 51 healthy subjects [ 29 ]. Acquisition schemes, vendor and field strength were similar as in our study, only with differences existing in scanner and post-processing approach [ 29 ]. Despite this, T1 values (1200.1 ± 30.7 ms) and T2 values (39.5 ± 1.8 ms) in their study were congruent to ours [ 29 ].…”

“…Acquisition schemes, vendor and field strength were similar as in our study, only with differences existing in scanner and post-processing approach [ 29 ]. Despite this, T1 values (1200.1 ± 30.7 ms) and T2 values (39.5 ± 1.8 ms) in their study were congruent to ours [ 29 ]. The Z-score publication regarding quantitative mapping in CMR included 15 healthy volunteers which were scanned with a 5-3-3 MOLLI scheme using the same scanner as site I [ 16 ].…”