Usefulness of carotid ultrasonography and treatment of carotid disease

Carotid stenosis is an important etiology of ischemic stroke. Most of the strokes associated with carotid stenosis are caused by artery-to-artery embolism. The risk of embolism highly depends on the stenosis degree and the vulnerability of the carotid plaque. Carotid ultrasonography is useful for evaluating the characteristics of carotid plaque. This review aims to provide information on performing and interpreting the result of carotid ultrasonography and the treatment of carotid artery disease based on the current guidelines. The degree of stenosis can be measured by the diameter reduction and flow velocity criteria. The risk of embolism is highest when the stenosis degree is around 70% to 80%. A heterogeneous echolucent plaque with an irregular surface or an ulcer shows a high risk of embolism. Appropriate treatment is important for the patients with carotid stenosis. In symptomatic patients, a potent antiplatelet treatment, especially during the acute stage, is beneficial. Patients with asymptomatic stenosis over 50% can also be considered for antiplatelet treatments. The associated risk factors should be managed according to the targets. Medically intractable cases or patients with high risk of embolism may receive carotid endarterectomy or carotid artery stenting depending on the concomitant disease and the degree of carotid stenosis. Considering the safety of ultrasound imaging, treatment may be followed-up by carotid ultrasonography.