Table 1. A typical carotid CEUS protocol.

Parameter	Reference value/setting
MI	<0.1
UCA dose	2.4 mL of SonoVue®, followed by 5–10 mL of normal saline
Injection pattern	Bolus injection usually performed
	Infusion technique with special injector is also available for prolonged time of enhancement
Injection site	Usually antecubital fossa vein
	Central venous lines and ports can also be used
Cannula required	A 20-gauge cannula can be safely used to avoid microbubbles disruption (18–21-gauge cannulas can result in similar enhancement) (15)
CEUS technique	Pulse-inversion technique should be used although other techniques are also available in different manufacturers (e.g., amplitude modulation)
Appearance of microbubbles	This depends on vessel examined and the patient’s circulatory status but microbubbles usually appear in the carotid arteries in 20–30 seconds
Duration of enhancement	Depending on scanning parameters, the enhancement may last up to 4 minutes
General comment	Albeit of UCA excellent safety profile, resuscitation equipment and trained personnel should always be available for treatment of allergic reactions

CEUS, contrast-enhanced ultrasound; MI, mechanical index; UCA, ultrasonographic contrast agent.