Use of Contrast-Enhanced Ultrasound in Carotid Atherosclerotic Disease: Limits and Perspectives

Abstract

Contrast-enhanced ultrasound (CEUS) has recently become one of the most versatile and powerful diagnostic tools in vascular surgery. One of the most interesting fields of application of this technique is the study of the carotid atherosclerotic plaque vascularization and its correlation with neurological symptoms (transient ischemic attack, minor stroke, and major stroke) and with the characteristics of the “vulnerable plaque” (surface ulceration, hypoechoic plaques, intraplaque hemorrhage, thinner fibrous cap, and carotid plaque neovascularization at histopathological analysis of the sample after surgical removal). The purpose of this review is to collect all the original studies available in literature (24 studies with 1356 patients enrolled) and to discuss the state of the art, limits, and future perspectives of CEUS analysis. The results of this work confirm the reliability of this imaging study for the detection of plaques with high risk of embolization; however, a shared, user-friendly protocol of imaging analysis is not available yet. The definition of this operative protocol becomes mandatory in order to compare results from different centers and to validate a cerebrovascular risk stratification of the carotid atherosclerotic lesions evaluated with CEUS.

Risk Factors of Large Artery Atherosclerotic Ischemic Stroke Based on Carotid Contrast-Enhanced Ultrasonography

“…Consistent with these ndings, hypoechoic plaques tend to have more vulnerable pathologic features, abundant lipids, and hemorrhage and are associated with an increased risk of cerebrovascular events [32]. Varetto et al reported a statistically signi cant correlation between increased vascularization of carotid atherosclerotic plaques evaluated by CEUS and cerebrovascular neurological events [30]. Similarly, Wu et al concluded that strong contrast enhancement can reveal culprit lesions, likely suggesting greater neovascularization and/or in ammatory activity in atherosclerotic lesions [36].…”

“…Unstable atherosclerotic carotid plaques are particularly vulnerable to rupture, which is induced by the loss of thin brous cap integrity, strong intraplaque in ammatory reaction, and luminal blood communication with the thrombogenic core of the plaque. [29,30] Thrombogenic material is diffused into circulation after plaque rupture, thereby occluding the intracranial cerebral arteries and resulting in ischemia of cortical and subcortical brain tissue. However, identi cation of vulnerable atherosclerotic plaques in patients poses a signi cant clinical challenge.…”

Preoperative and Postoperative Evaluation of New Double Mesh Carotid Stents with Contrast-Enhanced Ultrasound and Diffusion-Weighted Imaging

“…However, CEUS is not commonly used in routine practice yet, so there is no consensus on which quantitative parameters could discriminate between a ''stable'' and an ''unstable'' plaque, also because different machines and softwares are used. 9 In a previous work by our institution, 8 we used SI mean and SI maximum as parameters of blood perfusion in a ROI of the plaque detected at CEUS examination. We found a correlation between high values of SI mean and SI maximum (> 20 and > 26, respectively) and DW-MRIedetected cerebral microembolization after CAS.…”

Prediction Of Ischemic Stroke By Femoral Arterial Plaque Using Contrast-Enhanced Ultrasound In Elderly Patients

“…Researchers [6][7][8] have reported that the main sources of cerebral microemboli are the extracranial and intracranial arteries and that an atherosclerotic carotid artery is the most common source. Therefore, in ultrasonic research, the carotid is the most common window through which the relevant factors for stroke are investigated [14,15] . The members of our study group performed numerous investigations [10] on the microvascular distribution of carotid plaques; they also explored the microvascular distribution of carotid plaques in patients who are at risk of ischemic stroke.…”