Visualization of carotid plaque neovascularization with B-flow imaging in patients reffered for catotid endarterectomy

Abstract

Purpose: To elucidate the critical role of intraplaque neovascularization of microvessel-derived intraplaque hemorrhage in the development of acute lesion instability. We designed this study to visualize carotid plaque neovascularization using B-flow imaging, which can visualize microvascular flow. Subjects and Methods: Seven patients (7 men, 68.6±4.8 yrs) who had been referred for carotid endarterectomy were enrolled.Carotid ultrasound examinations were carried out using a Vivid 7 system with a multifrequency linear array transducer. Measurement of carotid plaque echogenity was based on gray-scale median (GSM) value. Intraplaque microvascular flow signals were carefully assessed by B-flow imaging. Results and Discussion: Intraplaque flow signals were observed in six patients. Gray-scale median values of these plaques were low (32±10). Multiple flow signals were observed in three patients in whom histologic studies revealed enhanced neovascularization with a lipid-rich core. In two patients whose intraplaque flow signals were situated at the peri-adventia, histologic studies revealed massive intraplaque hemorrhage with a necrotic core. In one patient, plaque producing no flow signals showed greater fibrous change, more calcification, and less neovascularization. Conclusion: B-flow imaging visualized intraplaque flow signals and provided additional information on plaque characterization.