Colour Doppler Evaluation of Extracranial Carotid Arteries: A Clinical and Radiological Correlation

Abstract

Introduction: Atherosclerosis (i.e. hardening and thickening of arteries) causes vascular remodeling, obstruction of lumen, abnormalities of blood flow and reduced oxygenation of target tissues. Manifestation of atherosclerosis in the form of either Myocardial Infarction or Stroke is the major cause of morbidity and mortality. This study evaluated extracranial carotid arteries of patients (>60 years) who presented with risk factors of atherosclerosis and determined the association of risk factors with carotid abnormalities. Aim: To evaluate the prevalence of atherosclerosis, haemodynamic and morphological changes that take place in extra cranial portion of carotid arteries in patients with risk factors of atherosclerosis (Diabetes Mellitus, Hypertension, Smoking, Stroke, Coronary Artery Disease, Hypercholesterolaemia) and determine the association of risk factors with carotid abnormalities. Materials and Methods: The prospective cross-sectional analytical study included the examination of Extracranial carotid arteries of 1043 patients over a period of 2 years (2013-2015) using duplex ultrasound. Assessment of CCA-IMT, ICA-IMT and percent stenosis was done using a linear probe of 8-12 MHz. Statistical Analysis: Correlation between risk factors of atherosclerosis, wall thickness of common carotid (CCA-IMT), internal carotid arteries (ICA-IMT) and stenosis was studied using statistical tools like multiple logistic regression analysis and analysis of variance (p70%) was low while the prevalence of mild stenosis (<50%) was quite high. In all age groups, stenosis was more prevalent and more severe in men as compared to women. Hypertension showed the strongest positive correlation with all three measures of interest CCA-IMT, ICA-IMT and maximum percent stenosis. Stroke history showed strong positive correlation with CCA-IMT and stenosis. Smoking, Diabetes Mellitus, Hypercholesterolaemia, Heart disease showed strong association with all three measures as well. Atherosclerotic plaques were mostly found at the site of carotid bifurcation. Conclusion: CCA-IMT was strongly associated with hypertension, smoking and diabetes mellitus. ICA-IMT was strongly associated with hypertension and history of heart disease. Percent stenosis was strongly associated with smoking and history of heart disease.

Keywords

• atherosclerosis
• intima-media thickness
• plaque
• stroke
• stenosis
• ultrasound