B-Mode Doppler Ultrasound Blood Flow Velocity Measurements for the Determination of the Intima Media Thickness in the Human Carotid Artery

Abstract

Excess mortality associated with cardiovascular diseases and stroke is linked to atherosclerosis which in turn, is related to the intima-media thickness (IMT). An increase in IMT in the common carotid artery (CCA) is therefore commonly used as a marker of atherosclerosis. The purpose of this study was to investigate the relationship between blood flow velocity and IMT in the CCA which is also an indicator of atherosclerosis in the carotid bifurcation. Fifty (50) apparently healthy volunteers (25 males and 25 females) whose ages ranged between 19 and 75 years were considered for carotid ultrasound scanning in Jos University Teaching Hospital (JUTH). IMT, Peak Systolic and End Diastolic blood velocities of the right and left Common Carotid Arteries (CCA) were measured by means of a Doppler Ultrasound Machine Type LOGIQ 5 EXPERT at 6MHz frequency with an insonation angle of 60⁰ by a single trained sonologist. Quantitative variables were analyzed with the IBM SPSS. Results show that the Right Peak Systolic Velocity (RPSV) and the Left Peak Systolic Velocity (LPSV) of blood in the CCA correlate negatively with the Right Intima Media Thickness (RIMT). The LPSV of blood shows a negative correlation with the Left Intima Media thickness (LIMT) but the RPSV has no significant correlation with the LIMT. The RIMT and the LIMT show a strong positive correlation with age but no significant correlation with sex, Right End Diastolic Velocity (REDV) and Left End Diastolic Velocity (LEDV). The RPSV and REDV also show a negative and positive correlation with age respectively, but the LPSV and LEDV show no significant relationship with age. We therefore conclude that the RPSV and LPSV of blood in the CCA is correlated to the degree of atherosclerosis in the carotid bifurcations more than the REDV and LEDV. The degree of atherosclerosis increases with advancing in age because of the strong positive correlation between IMT and age.

Keywords: Intima-Media Thickness, Common Carotid Artery, Atherosclerosis.