Comparison of ultrasound radiation force and fluid pressure generated waves in arterial vessels

Pulse wave velocity (PWV) is widely used for estimating the stiffness of an artery. It is well known that a stiffened artery can be associated with various diseases and with aging. The pulse wave generated by the blood pressure in the artery is a fluid-borne pressure wave. In a series of recent studies, we propose directly generating a bending wave in the arterial wall using the ultrasound radiation force and measuring the wave velocity in the arterial wall. With the bending wave method, the wave velocity can be measured accurately over a few millimeters. The bending wave in the artery is a structure-borne wave. In this paper the mechanism of these two kinds of waves are studied. It is found by experiment that the pressure wave velocity decreases with frequency while the bending wave velocity increases with frequency.