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

Abstract

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.

Keywords: T1ρ mapping; cardiovascular magnetic resonance imaging; normal values.