The Predictive Value of Carotid Doppler Ultrasound Findings for Stroke Risk Assessmen

Atherosclerosis of carotid arteries is a common serious condition that develops when sticky plaque builds up inside carotid arteries that deliver blood to brain, so carotid artery diseases cause about 10-20 percent of strokes which is a medical emergency that can leave the brain with permanent damage.

Doppler sonography of the cervical segment of carotid arteries is a popular non-invasive tool for evaluation of anatomy and hemodynamics of carotid artery (1), its ability to measure intimal media thickening and characterizes the morphology of carotid atheroma makes it a reliable modality to determine the etiology and severity of stroke (3), (4). Carotid intimal media thickening is measured as the distance between the leading edges of the two echogenic layers of the wall using the posterior wall (5), in addition color Doppler ultrasonography permits measurement of flow based on reflection of ultrasound waves utilizing both pulse Doppler and color Doppler ultrasound. Visualization of color coded flow information about direction and velocity, so with high grade lesions are more easily detected with color than with pulsed Doppler ultrasound although the later allows direct estimation of flow velocity The peak systolic velocity (PSV) is used for quantification of stenosis, however end diastolic velocity (EDV), carotid index and spectral wave form analysis are also used for assessment of stenosis (6).

Also, color integration is used to identify areas of abnormal flow. There are a number of pitfalls when using velocity based estimation of ICA stenosis, such as higher velocities in females, and elevated velocities where there's contra lateral carotid artery occlusion .(7_9) If there is a severe tortuosity of an artery, high carotid bifurcation, obesity, or extensive calcification of the vasculature, these will reduce the sonographic accuracy; if carotid artery stents are already in situ , vessel wall compliance can be diminished accelerating flow velocity.(10) Ultrasound may also be unable to distinguish between partial and complete vessel occlusion, despite the distinction being critically clinically important. (10-12).

In this study we present analysis of findings of carotid ultrasound examination among patients with clinical suspicion and risk for cerebrovascular diseases in New Valley.

Ultrasonography in this study is used to measure intimal thickening as well as flow characteristics of carotid artery with focus on internal carotid artery.