Age- and Sex-Related Variations of Myocardial T2: Insights from Quantitative Mapping in a Healthy Ukrainian Population

Abstract

Background. Cardiac magnetic resonance imaging (CMR) is recognized as the gold standard for non-invasive myocardial tissue characterization. Quantitative T2 mapping provides a direct measurement of myocardial transverse relaxation time (T2), which reflects tissue water content and serves as an objective marker of myocardial edema. Prolonged T2 values indicate increased free water content and are commonly associated with inflammation, ischemic injury, or with myocarditis. Unlike conventional T2-weighted techniques such as T2-STIR, which are prone to motion artifacts and subjective interpretation, T2 mapping enables absolute, reproducible, and quantitative assessment of myocardial tissue. However, reference T2 values remain insufficiently defined for the Ukrainian and broader Eastern European populations, particularly in pediatric cohorts. Establishing such reference ranges is crucial for accurate clinical interpretation and differentiation between physiological variability and early myocardial pathology.

Aim. This study aimed to establish age- and sex-specific reference values for myocardial T2 relaxation time in a healthy Ukrainian population and to evaluate potential influence of age and sex on these parameters.

Materials and Methods. A total of 310 healthy individuals (196 adults and 114 children and adolescents) underwent CMR on a 1.5 Tesla scanner using a standardized T2-prepared balanced steady-state free precession (bSSFP) sequence. Measurements were acquired at mid-ventricular short-axis levels, excluding blood pool and epicardial fat. Data were analyzed using IBM SPSS Statistics v26 and GraphPad Prism v10. Normality was assessed with the Shapiro–Wilk test. Group comparisons employed independent-sample t-tests, one-way ANOVA, or nonparametric Kruskal–Wallis tests as appropriate, with statistical significance set at p<0.05.

Results. The overall mean myocardial T2 value across the cohort was 45.1±2.7 ms (range 31-50 ms) with a normal distribution. In adults, mean T2 was 45.0±2.6 ms, and in children 45.3±2.8 ms (p>0.05). Age-stratified analysis among children revealed no significant differences between infants, early childhood, school-age, and adolescents (ANOVA F=0.16, p>0.05). In adults, women exhibited slightly higher T2 values than men (46.0±3.3 ms vs 44.6±2.2 ms; t=3.42, p<0.001), consistent with previously reported sex-related variability. In pediatric cohorts, no significant sex-based difference was observed (45.3±2.7 ms vs 45.3±2.9 ms; p=0.98). Visual analysis using boxplots and violin plots confirmed symmetric distributions, overlapping interquartile ranges, and the absence of age-dependent trends.

Conclusions. Myocardial T2 mapping using a T2-prepared bSSFP sequence at 1.5 T provides stable, reproducible, and physiologically consistent quantitative measurements across all age groups. The unified reference interval of 45±3 ms can be applied for both pediatric and adult populations. Slightly higher T2 values in adult women should be considered a normal physiological variation rather than a pathological indicator. These results establish foundational reference data for myocardial T2 mapping in the Ukrainian population and support its clinical use for accurate, contrast-free quantification of myocardial tissue characteristics across the lifespan.