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Diagnosis of various pathologies of cerebral vessels is an urgent issue, since cases of strokes, which are accompanied by disability, disability and death, have become more frequent. Statistics show that only 40% of people after a stroke can return to a full life.
Doppler ultrasound is the leading examination method that can be used to identify various lesions of the brachiocephalic arteries.
To understand what is meant by the words “brachiocephalic arteries”, you need to trace their path to the brain from the aorta. The blood flow that comes from the aortic arch is distributed into 3 large arteries: common carotid, left subclavian artery, brasiocephalic trunk. The latter is further divided into 3 arteries, which are located on the right side: subclavian, carotid, vertebral.
All of these vessels in one way or another take part in the blood supply to the shoulder girdle and, directly, to the brain. At the same time, they form a complex system in the form of a vicious circle, which allows you to evenly distribute the entire volume of blood in order to ensure adequate blood supply. Violation of blood flow can lead to redistribution of blood.
Ultrasound diagnosis
The study of arteries using ultrasound is the most informative diagnostic method that allows you to identify physiological changes. In addition, you can determine the qualitative and quantitative parameters of blood flow.
Ultrasound scanning, which is used to diagnose pathologies of the above arteries, is divided into 2 types: Doppler ultrasound and duplex scanning.
The basis of the two methods is the Doppler effect. Its essence lies in the fixation of an ultrasonic wave from objects that move. Moving objects that move and reflect ultrasound are red blood cells.
The ultrasound monitor displays the change in frequency as a color image. Red is positive shift, blue is negative shift.
The positive side of the BCA ultrasound method is the ability to examine the arteries that are inside the skull. At the same time, classical ultrasound does not have such capabilities.
The negative side is the inability to accurately determine the position of the vessel. Therefore, diagnosis is based on the probable location and changes in the depth of the scan.
Ultrasound of the brachiocephalic arteries is performed by specialists on an ultrasound scanner, which combines the classic study in β-mode and Dopplerography.
It is possible to assess the condition of the arteries and the quality of blood flow based on a two-dimensional and three-dimensional image. The vessel can be seen both in the transverse plane and in length.
It is also possible to use extracranial ultrasound. This method allows you to examine the vessels that are outside the cranium and get the following information about them:
- the state of the walls;
- thickness, structure and number of atherosclerotic plaques;
- education size;
- blood flow rate;
- the presence of aneurysms and other pathologies.
Reasons for the study
Ultrasound of the brachiocephalic arteries is prescribed to determine pathological changes that lead to circulatory disorders and cerebral ischemia. The reasons may be:
- atherosclerosis of the arteries;
- elongation and deformation of blood vessels;
- stenosis;
- the presence of thrombi.
Causes of disorders of the vascular system
The main cause of pathological changes in the brachiocephalic vascular system is atherosclerotic lesions of the arteries. A study conducted for people with relatively good health showed the presence of atherosclerosis in the initial stage in 3 percent of those surveyed. Their age ranged from 40 to 50 years. This result may indicate a fairly high probability of stroke in people after 55-60 years.
Atherosclerotic changes are considered an indirect cause of structural changes in blood vessels. For example, the appearance of tortuosity.
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Indications for this procedure may be the following diseases and symptoms:
- pain in the head (permanent and periodic);
- loss of consciousness, dizziness;
- hypertension or hypotension;
- noticeable deterioration of vision;
- diabetes mellitus, hypothyroidism;
- elevated levels of lipids in human blood, obesity.
Explanation of results
The first sign of atherosclerosis, which can be detected by ultrasound, is an increase in the thickness and density of IMT (intima-media complex). The vessel wall has 3 layers. The intima is the inner lining that is lined with endothelium. It consists of: collagen fibers and an elastic membrane. The thickness is equal to 1/10 of the thickness of the media. The media is the middle and thickest shell. It consists of: elastic membranes and smooth muscle cells. Arteries that are located outside the cranium have the same elastic membrane on the outside.
Adventitia is the outer shell of the vessel. Its structure consists of randomly arranged collagen and elastic fibers and the smallest blood vessels. It is these vessels that provide nutrition to the walls of the arteries.
On duplex scanning of the brachiocephalic arteries, the inner and middle membranes are clearly visible, while the outer one merges with the tissues and is not visible.
In the process of studying CIM, an analysis of hyperechogenicity and a visual separation of the inner and middle shells are carried out.
Often in patients with atherosclerosis, the following changes are observed that occur in IMT:
- areas with uncharacteristic echostructure appear;
- there is no obvious differentiation into layers or new layers with different echogenicity appear;
- wall thickening appears.
There are three types of atherosclerotic plaques: smooth and with a complex surface, hypoechoic or hyperesogenic, homogeneous or heterogeneous. Detecting plaques, their structure is analyzed.
The interpretation of the results of ultrasound of the brachiocephalic arteries contains data on the blood flow velocity in different parts of the arteries. A characteristic phenomenon for atherosclerotic changes in the carotid artery is an increase in blood flow velocity during the period of cardiac output (systole).