Cardiac T1ρ Mapping Values Affected by Age and Sex in a Healthy Chinese Cohort

Background To facilitate the clinical use of cardiac T1ρ, it is important to understand the impact of age and sex on T1ρ values of the myocardium. Purpose To investigate the impact of age and gender on myocardial T1ρ values. Study Type Cross‐sectional. Population Two hundred ten healthy Han Chinese volunteers without cardiovascular risk factors (85 males, mean age 34.4 ± 12.5 years; 125 females, mean age 37.9 ± 14.8 years). Field Strength/Sequence 1.5 T; T1ρ‐prepared steady‐state free precession (T1ρ mapping) sequence. Assessment Basal, mid, and apical short‐axis left ventricular T1ρ maps were acquired. T1ρ maps acquired with spin‐lock frequencies of 5 and 400 Hz were subtracted to create a myocardial fibrosis index (mFI) map. T1ρ and mFI values across different age decades, sex, and slice locations were compared. Statistical Tests Shapiro–Wilk test, Student's t test, Mann–Whitney U test, linear regression analysis, one‐way analysis of variance and intraclass correlation coefficient. Significance: P value <0.05. Results Women had significantly higher T1ρ and mFI values than men (50.3 ± 2.0 msec vs. 47.7 ± 2.4 msec and 4.7 ± 1.0 msec vs. 4.3 ± 1.1 msec, respectively). Additionally, in males and females combined, there was a significant positive but weak correlation between T1ρ values and age ( r = 0.27), while no correlation was observed between the mFI values and age ( P = 0.969). Data Conclusion We report potential reference values for cardiac T1ρ by sex, age distribution, and slice location in a Chinese population. T1ρ was significantly correlated with age and sex, while mFI was only associated with sex. Evidence Level 2 Technical Efficacy Stage 1