T1 mapping in population ageing

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background The world’s population is ageing: every country is experiencing growth in both the size and the proportion of older people. Common health states in older age mainly include cardiovascular disease. To ensure that our health system is ready to face this demographic shift, we investigated native and post-contrast T1 mapping as a quantitative method to appraise its clinical potential in older people. Purpose This article aimed to provide reference values of T1 mapping for quantification of the expansion of the extracellular matrix in older people. Methods We retrospectively selected subjects ranged in age from 86 to 101 years old that underwent contrast cardiac magnetic resonance (CMR). All subjects were imaged on a 1.5 T system. T1 measurements were performed with a Modified Look Lockers Inversion (MOLLI) recovery sequence. Regions of interest (ROI) were drawn in the left ventricle for blood T1 measurement and in the interventricular septum. We used T1 data obtained before and after contrast injection. We also measured the volume and function of both ventricles. Rho di Spearman was used for correlations. Results We analysed 29 patients (mean age 88.58±3.13 years old). Mean value of T1 in the blood pool (T1bp) was 1647.43±107.66 before contrast and 357.18±63.94 after contrast. Mean value of T1 in the septum (T1s) was 1012.86±38.41 before contrast and 488.68±69.29 after contrast. Left ventricle (LV) EDVI was 48.11±15.29 ml/m2 and ESVI 16.49±8.59 ml/m2, LV ejection fraction (EF) and stroke volume (SV) were 66.38±9.65 % and 52.39±18.84 ml respectively. Right ventricle (RV) EDVI was 46.44±13.19 ml/m2 and ESVI 16.97±5.93 ml/m2, LV ejection fraction (EF) and stroke volume (SV) were 63.46±8.65 % and 49.29±18.63 ml respectively. A significant negative correlation was found between age and T1s before contrast (r=-0.405 and p = 0.015). Positive correlations were found also between T1s before contrast and LV volumes. Conclusions This study shows a correlation between T1 mapping and population ageing.