Development of real-time elastic characteristics measurement system for ultrasonic-based tissue characterization of arterial wall

For measurement of minute change in thickness using ultrasound, the phase tracking method based on the constraint least-squares approach has been developed. By using the thickness change of arterial wall measured by this method, local elastic characteristic of the arterial wall is calculated, and fast calculation makes a real-time 2D measurement of the elastic characteristics possible. We have developed a real-time measurement system that displays the 2D image of the elastic characteristics of the arterial wall. In order to assess the measurement accuracy of the system, we made a phantom of silicone tube, and the thickness change of the tube wall was measured by the system and another off-line ultrasound measurement system. From the experimental results, it was obtained that our novel system had an accuracy of about 0.2 μm. using this system, we measured the thickness change of carotid arterial wall, and obtained real-time 2D images of the elastic characteristics.