Table 2. Sonographic markers of carotid plaque vulnerability on CEUS.

Marker	Classification
Carotid plaque surface	Smooth plaque surface
	Plaque surface irregularities (<1–2 mm)
	Plaque ulceration (>1–2 mm)
Carotid intraplaque neovascularization	Semi-quantitative measurement:
	Grade 1: no vascularization
	Grade 2: limited or moderate vascularization
	Grade 3: extensive vascularization
	Semiautomatic quantitative measurement: e.g., relative perfused area, plaque mean intensity

CEUS, contrast-enhanced ultrasound.