Reproducibility of functional aortic analysis using MRI: the multi-ethnic study of atherosclerosis

Methods Twenty-five participants underwent aortic MRI twice over 13 ± 7 days. All aortic variables (ascending aortic area, descending aortic area, ascending and descending aortic strain [maximum area minus minimum area divided by minimum area], aortic arch transit time and pulse wave velocity [PWV]) from baseline and repeat MR were analyzed using a semi-automated method by the ARTFUN software. Phase contrast (PC) cine at the level of the pulmonary artery bifurcation was used for assessment of aortic area, aortic strain, and PWV. Steady State Free Precession (SSFP) sagittal images were used to measure aortic arch transit distance. To assess the inter-study reproducibility of aortic variables, we calculated intraclass correlation coefficient (ICC) for individual aortic measurements. Intraand inter-observer variability was also assessed using the baseline MR data.