[Radial motion of the carotid artery wall: a block matching algorithm approach]

During recent years, evaluating the relation between mechanical properties of the arterial wall and cardiovascular diseases has been of great importance. On the other hand, motion estimation of the arterial wall using a sequence of noninvasive ultrasonic images and convenient processing methods might provide useful information related to biomechanical indexes and elastic properties of the arteries and assist doctors to discriminate between healthy and diseased arteries. In the present study, a block matching based algorithm was introduced to extract radial motion of the carotid artery wall during cardiac cycles. The program was implemented to the consecutive ultrasonic images of the common carotid artery of 10 healthy men and maximum and mean radial movement of the posterior wall of the artery was extracted. Manual measurements were carried out to validate the automatic method and results of two methods were compared. Paired t-test analysis showed no significant differences between the automatic and manual methods [P>0.05]. There was significant correlation between the changes in the instantaneous radial movement of the common carotid artery measured with the manual and automatic methods [with correlation coefficient 0.935 and P<0.05]. Results of the present study showed that by using a semi automated computer analysis method, with minimizing the user interfere and no attention to the user experience or skill, arterial wall motion in the radial direction can be extracted from consecutive ultrasonic frames.