Pitfalls in color Doppler ultrasound of carotid-vertebral arteries

The article was professionally consulted by Specialist Doctor I Tran Cong Trinh - Radiologist - Radiology Department - Vinmec Central Park International General Hospital. The doctor has many years of experience in the field of diagnostic imaging.

Color Doppler ultrasound of the carotid artery as well as Doppler ultrasound of the vertebrae are very valuable methods in the diagnosis and treatment of circulatory system diseases and a number of other related diseases. However, there are also many limitations and certain pitfalls when using these techniques, making diagnoses and treatment indications misleading.

To find out which atherosclerotic plaques as well as other causes of ascending embolism, carotid color Doppler ultrasound and vertebral Doppler ultrasound are the preferred options in this field because these are the most common techniques. Non-invasive imaging technique, fast, safe for patients and still very effective.
This method uses ultrasound energy to record images and characteristics of the artery, helping doctors to investigate pathological abnormalities in the artery such as atherosclerotic plaque, narrowing of the arteries. , embolism... The patient will be used a transducer that emits ultrasound waves, put on the neck where the arteries are to be examined, the emitted ultrasound will cause blood vessel cells and cells to grow. The echoluminescent cells help the images inside the vessel to be recorded clearly and completely. Although there are very high efficiency in diagnosing and giving treatment indications for patients, carotid color Doppler ultrasound and vertebral Doppler ultrasound can still cause some confusion in the diagnostic process. This is only a subjective subclinical means to support the diagnosis, which means that the results of ultrasound depend on the qualifications and experience of the person performing the ultrasound technique so much that it cannot be determined. is crucial for the diagnosis and treatment of the disease.
See more: Procedure for performing ultrasound of carotid and vertebral arteries

Some pitfalls in Doppler ultrasound make pathological judgments as well as diagnoses misleading, and how to handle these problems are as follows:
The lumen is severely narrowed but the ultrasound results confirmed case of embolism: Leaving very serious consequences in the choice of treatment method because if it is severe stenosis, it is still possible to have surgery to remove the endothelium or put a bracket, but if it is an occlusion vasculature is not indicated for surgery. For these cases, in ultrasound it is necessary to reduce the color velocity scale to less than 15cm/s to be able to recognize the signal of low blood flow rate. The blood vessels are normal, but the diagnosis is occlusion and stenosis: The cause of this confusion is because the blood vessels are located deep, so it cannot be investigated with a Linear probe, often with the internal carotid artery and the vertebral artery. The fix is ​​to adjust the color box so that the Doppler angle is larger (≠ 90°), so that the higher flow velocity makes the color more sensitive, or it is possible to change the approach to the probe so that the artery is no longer located as deep as the blood vessel. probe again. Another reason is that because color Doppler is often qualitative in nature, it is not possible to recognize the blood flow rate accurately, so it is necessary to replace the color Doppler signal with pulse Doppler so that it can be quantified. than. In addition, the sonographer can also change to the Convex type of transducer to increase sensitivity to the signal in cases where both pulse and color Doppler signals cannot be recognized. The fake image causes motion, causing the pathology to be misdiagnosed to the direction of total vascular occlusion: Because the technician has to lower the color scale when he wants to examine the suspected stenosis and occlusion, the fake image appears. within and outside the lumen of the artery, causing uneven coloration and confusion in the diagnosis. The way to overcome this situation is to switch to energy Doppler and directional energy Doppler, which has the ability to reduce and lose image artifacts due to motion.

When the artery is completely occluded but the ultrasound image still shows the pulse Doppler spectrum: It is common in the case that the survey beam passes through 2 adjacent blood vessels causing spectral noise or noise on ultrasound, so there are many experience and careful observation when reading ultrasound results. Atherosclerotic plaques are fibrous and calcified at the position of the vessel wall, creating a shadow that covers the back and does not pass through the Doppler signal: The way to overcome this case is to change the approach to the transducer so as not to encounter In the fibrous and calcified part of the atherosclerotic plaque, there will be no dorsal shadow and Doppler can pass through. Carotid dissection: It is necessary to use color Doppler or redirect the transducer approach to avoid artifact in these cases. The open lumen causes misdirection to the normal state and without any pathology: It is caused by the color filling of the lumen due to the reversed flow. The remedy is to pay attention to the diagnosis based on the color direction on the color velocity scale, not only on the color of the flow, when there is an reverse flow condition, it is necessary to think of a medical condition although the blood flow is not normal. 1 color filling circuit. The narrowing of the artery was not measured accurately: Because of the selection of the narrowest point in the longitudinal section, this result does not reflect the actual narrowing of the lumen. Because the plaque can be eccentric, measuring the narrowness in the longitudinal section will not be accurate, it is necessary to measure the transverse section and select the narrowest place to measure. Absolutely compliance with pulse Doppler values, but currently there is no consensus on these indicators in the world, so it is easy to cause confusion: Because pulse Doppler values ​​up to now are only relative, so It is necessary to calculate the PSV ratio between ICA and CCA for accurate results.

Carotid color Doppler ultrasound and vertebral Doppler ultrasound are modern, highly effective paraclinical methods in the diagnosis and treatment of vascular diseases, but there are certain limitations that make these The diagnosis may have some errors. Therefore, it is necessary to understand the nature, principles as well as detailed characteristics of each method in order to be able to recognize these pitfalls, thereby having experience and solutions for each specific case.
For the most accurate diagnostic results of color Doppler ultrasound of the carotid arteries - vertebrae, you should go to reputable medical facilities, a team of technicians with good qualifications. Vinmec International General Hospital has a full system of modern carotid - vertebral artery ultrasound equipment, including color Doppler ultrasound, which is completely imported from abroad with modern technology. Clear images, multi-function, make diagnosis easier.
The team of technicians are all experienced and highly trained in imaging, so the incidence of pitfalls in color Doppler ultrasound of the carotid artery - vertebrae is very low, thereby giving correct and effective treatment.
If there is a need for color Doppler ultrasound of the carotid arteries - vertebrae, please book an appointment directly at the website or contact the hotline for detailed advice.