[Clinical cohort study of imaging evaluation and postoperative pathology of carotid vulnerable plaque]

Objective: To evaluate the accuracy of contrast-enhanced ultrasound(CEUS) scanning in identifying vulnerable plaque in carotid artery. Methods: The study included a total of 25 patients who suffered from carotid artery stenosis and underwent carotid endarterectomy from January 2016 to December 2017 in Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University. Preoperative carotid artery contrast enhanced ultrasound and High-resolution MRI were performed to all patients to determine whether the plaques were stable. All patients then underwent carotid endarterectomy, during which, plaques were completely removed. Biopsies were performed using HE staining and CD31, CD34 and SMA immunohistochemistry was used to identify the plaques properties, including the thickness and integrity of the fiber cap, neovascular endothelium, hemorrhage, and inflammatory cells in the removed plaques.The results of these tests were compared with the diagnosis through the pre-operative imaging. Results: Among twenty-five cases, the pre-operative CEUS revealed sixteen with unstable plaques and nine with stable plaques. Meanwhile the post-operation pathology confirmed seventeen cases with unstable plaque components. The sensitivity of CEUS in the identification of carotid vulnerable plaque was 88.2%(15/17), the specificity was 87.5%(7/8), and the overall diagnostic accuracy was 88%(22/25). The sensitivity, specificity and overall diagnostic accuracy of high resolution MR for vulnerable plaque identification were 83.3%(10/12), 71.4%(5/7), 78.9%(15/19), respectively. There were no significant difference between two groups(χ(2)=0.003, P>0.05). Conclusions: The sensitivity, specificity and overall diagnostic accuracy of the CEUS for vulnerable plaque identification are high.Therefore, CEUS is recommended as one of the pre-operative diagnostic method for unstable plaque in carotid stenosis.