Non-invasive imaging of carotid atherosclerosis

Carotid atherosclerosis is an important cause of stroke. Because stroke results in considerable morbidity, mortality, and costs, prevention is pivotal. Patient symptomatology and degree of luminal stenosis are currently the main grounds to perform carotid endarterectomy (cea). However, many patients undergo cea with its attendant risks without taking advantage, whereas in others cea is probably incorrectly withheld. Noninvasive imaging of carotid plaque characteristics may be used to improve risk stratification for stroke. Histopathologically, vulnerable plaques (i.e., plaques that have a high tendency to cause future thromboembolic events) are characterized by the presence of a large lipid-rich necrotic core with a thin overlying fibrous cap, neovasculature growth, macrophage infiltration, intraplaque hemorrhage, cell death, ulceration, and thrombogenicity. Several imaging modalities, including ultrasonography, transcranial doppler, magnetic resonance imaging, multidetector-row computed tomography, and nuclear imaging techniques may be used to characterize one or more of these plaque features in vivo. For each technique, accuracy and reproducibility, (dis)advantages and limitations, and clinical potential will be outlined.keywordscarotid atherosclerosisstrokeplaqueimaging