Extracting the small vibrations of a vessel wall.

Cardiac and vascular diseases are among the main causes of mortality. Diagnosis of these diseases in the early stages can be very helpful for their treatments. One of the effects of atherosclerosis is the reduction of vessel wall vibrations. Echocardiography images cannot show these vibrations, due to their lack of resolution. In this study a new model for vessel simulation in an ultrasonic system is proposed that can be used for RF signal generation for imaging vessel wall layers. To extract the high frequency vibrations, at the first stage large motion of the vessel wall due to heartbeat is removed from RF signals using continuous wavelet transform and then these simulated vibrations are estimated by calculating the phase difference between Hilbert transforms of signals. This method may be used to detect the areas with atherosclerotic plaque non-invasively and with a respectable spatial resolution. The proposed method has been used for real data from the inferior wall of the aorta and the anterior wall of the hepatic vein to evaluate the efficiency of this method for real ultrasound data.