Evaluating the inflammation levels of carotid atherosclerotic plaques by late-phase contrast-enhanced ultrasound.

Abstract

Inflammation in carotid atherosclerotic plaques is closely related to the occurrence of cerebrovascular events. Studies have shown that the use of contrast-enhanced ultrasound technology can assess the level of inflammation in the plaques, but there is no pathological-relevant research. In this study, contrast-enhanced ultrasound was used to assess the level of inflammation in the plaques of patients undergoing carotid endarterectomy (CEA) and to discuss the correlation among ultrasound parameters and clinical symptoms and histopathology. Fifty-four patients were selected to receive CEA due to carotid artery stenosis in Department of Neurosurgery, Third Xiangya Hospital, among which 3 patients received CEA surgery for bilateral carotid artery. The patients were divided into a symptomatic group (33 cases) and an asymptomatic group (21 cases) according to the diagnosis and treatment guideline of carotid stenosis of Chinese Medical Association. All patients received late-phase contrast-enhanced ultrasound (LP-CEUS) examination, and quantitative analysis was applied to observe the intensity of late-phase plaque enhancement and the relative intensity ratio of late-phase plaque enhancement. CD68 histopathological examination was performed on carotid artery plaque after surgery, the number of macrophage infiltration was calculated, and the correlation between ultrasound parameters and histopathology was analyzed by Pearson correlation. The intensity of late-phase plaque enhancement and the relative intensity ratio of late-phase plaque enhancement in the symptomatic group were significantly higher than those in the asymptomatic group, with statistically significant differences (P<0.05). The number of macrophages in the plaque in the symptom group was significantly higher than that in the asymptomatic group, and the difference was statistically significant (P<0.05). The intensity of late-phase enhancement and the relative intensity of late-phase plaque enhancement were positively correlated with the number of macrophages (r=0.69, r=0.65, respectively, both P<0.05). The parameters of LP-CEUS are helpful in assessing inflammation in carotid plaque. The degree of macrophage infiltration in plaque of patients with symptoms was higher than that of asymptomatic patients.