Simultaneous imaging of bidirectional guided waves enables synchronous probing of mechanical anisotropy, local blood pressure, and stress in arteries

TL;DR

This paper introduces an ultrasound elastography technique that simultaneously measures arterial anisotropic stiffness, mechanical stresses, and blood pressure within a single cardiac cycle, advancing cardiovascular diagnostics.

Contribution

It presents a novel method combining acoustic radiation force and a mechanical model to quantify multiple arterial biomechanical parameters simultaneously.

Findings

Successfully measured arterial stiffness and blood pressure in vivo.

Differentiated biomechanical properties across age and health conditions.

Potential applications in cardiovascular disease diagnosis and aging studies.

Abstract

Arterial biomechanical indicators have long been recognized as fundamental contributors to the physiology and pathology of cardiovascular systems. Probing the multiple biomechanical parameters of arteries simultaneously at different time points within one cardiac cycle is of great importance but remains challenging. Here we report an ultrasound elastography method to quantify arterial anisotropic stiffness, mechanical stresses in arterial wall, and local blood pressure in a single measurement. With programmed acoustic radiation force, arterial axial and circumferential guided elastic waves were induced simultaneously and recorded at multiple time points within one cardiac cycle. Then a mechanical model incorporating acoustoelasticity and viscoelasticity of arteries was proposed to quantitatively predict the correlation of arterial guided elastic waves with arterial biomechanical parameters. Our experimental design and biomechanical model lead to an elastography method to interrogate the variation of blood pressure, arterial bidirectional stiffnesses and mechanical stresses in arterial walls with time. In vivo experiments were performed on healthy young, normotensive older and hypertensive older volunteers. The results demonstrate that the reported method can find applications in understanding aging of cardiovascular system and diagnosis of cardiovascular diseases.