The effect of age and sex on T1, T2, and T2* relaxation time constants in cardiac MRI in healthy Finnish population

Background: Magnetic resonance imaging (MRI) enables the non-invasive assessment of myocardial tissue properties through the T1, T2, and T2* relaxation mapping. Establishing population-specific normal reference values enhances diagnostic accuracy. Purpose: To study the effect of sex and age on the T1, T2, and T2* relaxation time constants in a healthy Finnish population. Methods: We recruited 47 healthy volunteers aged 18-60 years from Eastern Finland from 2023 to 2024 and categorised them by sex and age (18-30 years, 31-41 years, and 42-60 years). The participants underwent a comprehensive screening process to eliminate the possibility of cardiac disease. MRI scans were conducted on 40 participants at 1.5 T. The T1, T2, and T2* relaxation time constants were calculated for basal, mid-ventricular, and apical short-axis slices. Results: < .001). The 95% normal T1 range was 981-1098 ms for females and 985-1054 ms for males. The normal T2 range was 44-58 ms for females and 43-53 ms for males. No sex differences were found in the T2* relaxation times. The septal T2* across the whole population was 36 ± 7 ms (95% normal limit: 22-49 ms). Conclusion: This study established age-independent and sex-specific reference values for the native myocardial T1, T2, and T2* relaxation time constants at 1.5 T. Females had higher T1 and T2 values than males, and age did not affect these values.