GOKHALE Sudheer

Sudheer GOKHALE

Sri Aurobindo Institute of Medical Sciences

キーワード :

【Introduction】
Population-based cohort studies have established that persons with carotid artery stenosis are at increased risk for subsequent stroke, myocardial infarction （MI）, and death. Depending on the underlying population characteristics, the positive predictive value of carotid duplex ranges from 82％ to 97％. As technology has improved and confidence in ultrasound has grown, sonography has assumed an increasingly important role.
【Technique】
Scanning of the common, internal and external carotids is performed in order to image the lumen and its alterations by plaque. Usually 7.5 - 12MHz linear array transducers are used. The B Mode examination is followed by color flow mapping to assess the lumen. Color mosaics created due to aliasing indicate the site of stenosis. Pulsed Doppler spectral analyses is then performed to measure the peak systolic and end diastolic velocities.
【Carotid Intima Media Thickness as predictor of Atherosclerosis.】
Multiple studies have shown that the carotid artery intima-media thickness （IMT）. Because it has been shown to be an independent predictor of cardiovascular disease after adjustment for traditional risk factors, it is the only noninvasive imaging test currently recommended by the American Heart Association for inclusion in the evaluation of risk. Change in IMT is increasingly being used as the end point in interventional trials.
【Plaque Characterization】
Plaque configuration, constitution, surface, edges and other aspects are taken into consideration in the evaluation of severity of the lesion and may help to establish a surgical solution.
・Homogenous plaques: usually fibro fatty in consistency. Has a low incidence of neurologic events
・Inhomogeneous plaque: associated with high lipid content and internal hemorrhage. Associated with increased incidence of neurologic deficit.
・Calcification can occur either in homogenous or inhomogeneous plaque. Purely calific plaque is considered benign.
【Assessment of Carotid Artery Stenosis by Pulsed Doppler.】
Peak systolic velocity （PSV） as measured by duplex sonography is a widely accepted and reliable diagnostic method for assessing ICA stenosis. Recently, color Doppler flow imaging has shown not only high accuracy but also excellent reproducibility in the assessment of carotid stenosis.
Society of Radiologists in Ultrasound consensus conference on Carotid Ultrasound Oct 22-23, 2002. Radiol, 2003;229:340-346