Carotid Artery Color/Spectral Doppler Ultrasound Normal Vs Abnormal Images | ICA Stenosis USG

Summary

This video, presented by Dr. Sam, provides an in-depth exploration of carotid artery Doppler ultrasound. It covers the examination of the common and internal carotid arteries, focusing on conditions like atherosclerosis, plaque formation, stenosis, and dissection. Key ultrasound features, including intima-media thickness, plaque characteristics, and Doppler waveforms, are explained with examples. The video also discusses normal and abnormal flow patterns, the significance of various velocities, and the impact of conditions like aneurysms and stents on blood flow. A valuable resource for understanding carotid artery pathology and Doppler ultrasound interpretation.

Takeaways

• 😀 The common carotid artery (CCA) and internal carotid artery (ICA) are the primary vessels examined during carotid artery Doppler ultrasound, as most pathologies occur in these areas.
• 😀 Normal intima-media thickness (IMT) of the common carotid artery is less than one millimeter, and a thickness greater than one millimeter indicates an increased risk of atherosclerosis and plaque formation.
• 😀 Carotid plaques can appear as hypoechoic structures within the lumen and may be partially calcified, with the calcified areas appearing hyperechoic.
• 😀 Carotid plaque ulceration is difficult to detect by ultrasound but may present as irregular plaque shape and hypoechoic defects within the plaque, which increases the likelihood of embolization.
• 😀 Normal Doppler analysis of the internal carotid artery shows low resistance, broad systolic peak, and forward diastolic flow, with a peak systolic velocity (PSV) under 125 cm/s and end diastolic velocity (EDV) under 40 cm/s.
• 😀 Internal carotid artery stenosis is graded by Doppler velocity measurements, with a 0-49% stenosis showing normal PSV and EDV, while stenosis greater than 70% results in high PSV (>230 cm/s) and significant lumen narrowing.
• 😀 Near occlusion of the internal carotid artery presents with very low flow and low or undetectable Doppler velocities, often accompanied by a small waveform on spectral Doppler.
• 😀 Total internal carotid artery occlusion results in complete blockage of the lumen, with no detectable flow on color Doppler or spectral Doppler.
• 😀 Common carotid artery dissection can be identified by ultrasound showing two lumens and a dissection flap within the artery, which may be visible on color Doppler with color mixing.
• 😀 Stents in the carotid arteries can cause narrowing of the lumen over time, and a PSV of more than 300 cm/s at the site of stenosis indicates a stenosis of 70-80%.
• 😀 The normal diameter of the common carotid artery is between 4 and 7 millimeters, and aneurysms or pseudoaneurysms may cause abnormal dilation, often accompanied by Doppler signals within the pseudoaneurysm.

Q & A

What arteries are primarily examined in carotid artery Doppler ultrasound?

The common carotid artery and the internal carotid artery are primarily examined as most pathologies occur within these vessels.

What is the normal range for intima-media thickness in the carotid artery?

The normal intima-media thickness is less than one millimeter. If it is greater than one millimeter, it indicates an increased risk of atherosclerosis and plaque formation.

How does a carotid plaque appear on ultrasound?

A carotid plaque appears as a hypoechoic structure within the lumen and may be partially calcified. The calcified areas appear hyperechoic.

What are the characteristics of carotid plaque ulceration on ultrasound?

Carotid plaque ulceration may show an irregular shape and hypoechoic defects within the plaque. This type of plaque is more likely to cause embolization.

What is the normal Doppler flow pattern in the internal carotid artery?

The normal Doppler flow pattern in the internal carotid artery shows a low resistance waveform with a broad systolic peak and forward diastolic flow.

What are the normal velocity values for peak systolic velocity (PSV) and end diastolic velocity (EDV) in the internal carotid artery?

In normal cases, the peak systolic velocity (PSV) is less than 125 centimeters per second, and the end diastolic velocity (EDV) is less than 40 centimeters per second.

What is the significance of the ICA to CCA PSV ratio?

The ICA to CCA PSV ratio should be less than 2. A ratio greater than 2 may indicate stenosis or other abnormalities in the carotid artery.

How can a 50-69% stenosis in the internal carotid artery be identified on Doppler ultrasound?

In 50-69% stenosis, the PSV will range from 125 to 230 centimeters per second, and the EDV will range from 40 to 100 centimeters per second. The ICA to CCA PSV ratio will be between 2 and 4.

What is indicated by a PSV greater than 230 centimeters per second in the internal carotid artery?

A PSV greater than 230 centimeters per second, along with a large visible plaque and prominent lumen narrowing, indicates stenosis of more than 70% but less than near occlusion.

What is the appearance of common carotid artery dissection on ultrasound?

Common carotid artery dissection can show two lumens with a visible dissection flap between them. This is often visible on both transverse and longitudinal views of the artery.