Quantification of atherosclerotic plaques in carotid arteries by three ‐ dimensional ultrasound Year

IntroductIon Approximately 20%–30% of ischemic strokes are caused by the rupture of carotid artery plaques, and the percentage diameter reduction in the carotid arteries is used as an indicator for stroke risk. [1,2] The risk factors leading to plaque rupture, however, remain incompletely understood. Stroke rates achieved after guideline-directed carotid endarterectomy (CEA) for high-grade carotid stenosis in symptomatic patients (stroke/transient ischemic attack [TIA]) are significantly lower than those observed with best medical therapy alone; at the same time, in asymptomatic patients, the majority of medically treated patients remain stroke free during follow-up. [3] Moreover, in asymptomatic population, increasing degrees of stenosis have not been associated with a correspondingly increased risk for stroke/TIA. [4] It is, therefore, important to identify additional markers to assess the risk of stroke and to identify patients who would benefit most from revascularization. [5] Magnetic resonance imaging (MRI) is a sensitive and specific method for determining the plaque characteristics. [6,7] At present, computed tomography angiography is not much accurate in delineating plaque composition. It is, however, useful to identify the luminal surface outline. [8,9] Duplex ultrasonography (DUS) is the most widely available and low‐risk noninvasive test to assess carotid plaque severity, although its correlation with angiographically measured stenosis severity is low. [10] Two-dimensional (2D) B-mode imaging can visualize a number of anatomic features of the arterial wall and plaque. An important strength of ultrasonography is its ability to provide real-time physiologic The introduction of three‐dimensional echography (3D echo) in vascular field is not recent, but it still remains a seldom‐used technique because of the costs of ultrasound probe and the need of dedicated laboratories. Therefore, despite significant prognostic implications, the high diagnostic accuracy in plaque definition, and the relative ease of use, 3D echo in vascular field is a niche technique. The purpose of this review is mainly clinical and intends to demonstrate the potential strength of a 3D approach, including technical aspects, in order to present to clinicians and imagers the appealing aspects of a noninvasive and radiation-free methodology with relevant diagnostic and prognostic correlates in the assessment of carotid atherosclerosis. A comprehensive literature search (since 1990s to date) using the PubMed, MEDLINE, and Cochrane libraries databases has been conducted. Articles written in English have been assessed, including reviews, clinical trials, meta-analyses, and interventional/observational studies. Manual cross-referencing was also performed, and relevant references from selected articles were reviewed. The search was limited to studies conducted in humans. Search terms, retrieved also with PubMed Advanced search and AND/OR Boolean operators (mainly in title and abstract), included three-dimensional, echo, stroke/transient ischemic attack, predictors, carotid, imaging, and biomarkers.