STUDY OF AGE RELATED VESSEL WALL VIBRATION USING ULTRASOUND

ardiac and vascular diseases are among the main reasons of mortality.
Diagnosis of these diseases in the first 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 because of their lack of resolution.
Materials & Methods: This study was conducted on 24 persons and their radio frequency (RF) were
acquired from the carotid vessel. The test persons were divided into 3 groups (young under 35 years
old, middle aged between 35 to 55 years old, and old more than 55 years old); and the laboratory
conditions were similar for all cases. To extract the high frequency vibrations, at the first stage large
motion of vessel wall due to the heart beat was removed from RF signals using Phase Tracking
Method and Hilbert transform. In Hilbert method the large motion of vessel wall can be removed by
maximizing the cross-correlation between absolute value of Hilbert transforms of signals of two
corresponding windows in depth direction in consecutive frames.
Results: Quantitative measures were obtained for every individual and compared. It was revealed that
vibrations of the layers of the vessel wall decreased with increasing age. We find 2 new features which
can be used to categorize people according to their vessels’ age, which mean the ability of their
vessels’ wall vibration to help the blood flow in vessels.
Conclusion: Although it seems evident that aging leads to a decrease in vessel wall vibrations, we
attempted to find properties of distinction that could be used in further studies. Since this study was
conducted for the first time in Iran specifically to evaluate the carotid artery, it is expected that the
results would pave the way for future researches.