Internal carotid artery dissections: duplex ultrasound imaging

Area of Science:

• Vascular Imaging
• Neurology
• Diagnostic Ultrasound

Background:

• Extracranial internal carotid artery (ICA) dissection is a significant cause of stroke, particularly in younger individuals.
• Accurate and timely diagnosis is crucial for appropriate management and prevention of complications.
• Duplex ultrasound offers a non-invasive method for evaluating extracranial carotid arteries.

Purpose of the Study:

• To present and categorize duplex ultrasound findings in patients with extracranial internal carotid artery dissections.
• To correlate specific sonographic features and Doppler waveforms with the diagnosis of ICA dissection.

Main Methods:

• Retrospective analysis of duplex ultrasound examinations in seven patients (eight vessels) with confirmed extracranial ICA dissections.
• Categorization of two-dimensional (2D) sonographic findings, including luminal abnormalities and thrombus formation.
• Analysis of Doppler ultrasound waveforms in both the common carotid artery (CCA) and ICA.

Main Results:

• Sonographic findings included normal appearance, luminal flap with or without thrombus, and hypoechoic thrombus with or without lumen narrowing.
• Common carotid artery (CCA) waveforms varied, showing normal, resistive, damped, biphasic patterns, or a positive temporal artery tap.
• Internal carotid artery (ICA) waveforms included normal, damped, resistive, biphasic patterns, absent flow, or high-velocity flow.

Conclusions:

• Duplex ultrasound demonstrates characteristic, though nonspecific, findings in extracranial internal carotid artery dissections.
• Specific 2D sonographic features and Doppler waveform abnormalities can suggest ICA dissection in the appropriate clinical context.
• Duplex ultrasound is a valuable tool for the initial evaluation and diagnosis of extracranial ICA dissection.