University of Tarbiat Modarres,Tehran, Iran.
Background-Non-invasive evalualion of vessel wall properties in humans is hampered by the absence of methods to directly assess local elasticity. Contemporary ultrasound methods are capable of assessing end diastolic artery diameter, the local change in artery diameter as a function of time and local wall thickness.However,to assess vessel wall properties of the carotid artery, for example, the pulse pressure.in the brachial artery still must be used as a suitable example for local pulse pressure. The assessment of local static pressure as described in the present study provides a direct estimate of local vessel wall properties.
Methods- In 30 men, we estimated the static pressure-strain elastic modulus in the right common carotid artery (RCCA) under normal and atherosclerotic conditions. The detailed variation of the static pressure of RCCA throughout the carotid cycle was estimated by using the energy conservation law. The flow velocities during systole and diastole were measured using multi-frame image processing method of color Doppler ultrasonography. The static pressure-strain elastic modulus was defined as stress to strain.
Results- The results showed that: 1) the variation of the static pressure during the cardiac cycle was higher in the severe atherosclerotic group than that in both the mild atherosclerotic group and the normal artery group, respectively, 2) the relative increase in the vessel diameter during the cardiac cycle was lower in the atherosclerotic group than that in the normal, group and 3) the static pressure-strain elastic modulus in the atherosclerotic group was significantly different from that in normal individuals.
Conclusion- We concluded that by applying this method, we can detect the initial symptoms and disease process in atherosclerosis. This is an accurate and safe method suited to the screening of large populations of young and symptom-free individuals