Ultrasound strain mapping of the non-aneurysmal abdominal aorta for detecting age-related aortic stiffening.

Background: Aortic stiffness is a proxy for cardiovascular risk, but the methods are technically demanding. Ultrasound-based assessment of aortic wall strain patterns is established in abdominal aortic aneurysms but has never been described in the non-aneurysmal aorta. This study aimed to describe a workflow for ultrasound-derived strain mapping of the non-aneurysmal abdominal aorta and assess technical applicability, acquisition reproducibility, and age-related strain patterns. Methods: In this cross-sectional proof-of-concept study, healthy volunteers underwent ultrasound scanning of their non-aneurysmal abdominal aortas with standard equipment. Three independent operators scanned each participant. The ultrasound acquisitions were saved as short videos, or cine-loops, and were analysed off-line with prototype software to extract mean strain, strain heterogeneity, and circumferential strain patterns. Acquisition reproducibility was assessed with extended Bland-Altman statistics, and associations with age group and sex were analysed using regression models and functional data analysis. Results: Fifty-seven volunteers were included, generating 171 cineloops; all were suitable for strain analysis. Mean strain decreased with age from 8.70% in participants aged <30 years to 3.90% in those aged >50 years (P < .001), and strain heterogeneity was associated with age (P = .01). Mean strain and heterogeneity were not associated with sex. Inter-operator limits of agreement were ±1.5 mm for diameter, ±1.64 percentage points for mean strain, and ±0.18 for heterogeneity index. Conclusion: Ultrasound-derived strain mapping of the non-aneurysmal abdominal aorta is applicable and shows acceptable acquisition reproducibility. The method describes age-related differences in aortic strain, supporting validation as a future tool for assessing aortic stiffness and cardiovascular risk.