Normal variations of myocardial T1, T2 and T2* values at 1.5 T cardiac MRI in sex-matched healthy volunteers.

Abstract

Purpose: The purpose of this study was to determine the normal variations of myocardial T1, T2, and T2* relaxation times on cardiac MRI obtained at 1.5 T in healthy, sex-balanced volunteers aged between 18 and 69 years.

Material and methods: A total of 172 healthy volunteers were recruited prospectively. They were further divided into seven sex-balanced age groups (18-19 years, 20-24 years, 25-29 years, 30-39 years, 40-49 years, 50-59 years, and 60-69 years). T1, T2, and T2* mapping were acquired in a single short-axis slice at the mid-level of the left ventricle. Global T1, T2, and T2* values were the mean of all segments. Comparisons between females and males were performed in each age group using independent samples t-test or Wilcoxon rank sum test, as appropriate. Multivariable linear effects models were used to analyze the effect of heart rate, body mass index, left ventricular mass, age, and sex on T1, T2, and T2* values. Inter- and intra-observer correlation (ICC) was evaluated.

Results: A total of 172 healthy participants were included. There were 83 males and 89 females, with a mean age of 37.3 ± 15.6 (standard deviation [SD]) years. Females had greater T1 values (980.9 ± 26.2 [SD] ms) compared to males (949.7 ± 18.3 [SD] ms) (P < 0.001). T1 values decreased with age (974.3 ± 26.97 [SD] ms when ≤ 39 years vs. 954.4 ± 24.12 [SD] ms when > 39 years; P < 0.001), with smaller sex-related differences in older participants. Male sex and age were independently associated with lower values of T1 mapping. Age in females was independently associated with lower T1, T2, and T2* values. Moderate to good inter- and intra-observer agreement was found for T1, T2, and T2* (ICC ranging from 0.72 to 0.89).

Conclusion: T1, T2, and T2* values are influenced by age and sex, emphasizing the need to read and calibrate MRI values with respect to patient characteristics to avoid misdiagnosis.