Duplex scanning of vessels of the head and neck

Duplex scanning of brachiocephalic arteries( BSA) is a complex ultrasound study of the vessels of the head and neck. Non-invasiveness, safety, absence of strict contra-indications and age limitations in combination with sufficiently high informativeness make it one of the main diagnostic techniques in angioneurology.

procedure procedure. The essence of the

method. Duplex scanning is based on the reflection of ultrasonic waves from various tissues of the human body. This study includes two components: vascular scanning( B-mode) and Doppler. They can be used simultaneously or alternately, depending on the apparatus and the skills of a specialist in ultrasound diagnostics.

B-mode with duplex scanning is a two-dimensional seroscale echography. This is what is called "regular" ultrasound. The piezoelectric crystals located in the sensor of the instrument under the action of an alternating electric current generate ultrasonic waves. They focus and are directed to the investigated area of ​​the human body. Such radiation does not cause discomfort and does not cause harm. Fabrics and anatomical formations have different density and ability to absorb and reflect ultrasonic rays. The sensor senses the reflected signal, and based on the difference between the radiated and reflected wave, the apparatus program builds a two-dimensional( planar) black and white image.

B-mode allows you to visualize vessels of different calibers and surrounding tissues. In this case, the doctor evaluates the structure of their walls, reveals the presence of thrombi and plaques, measures the diameter of arteries and veins, determines their course and the presence of pathological extensions or constrictions.

Doppler ultrasound is a dynamic study that helps in real time to assess blood flow parameters. The method is based on the Doppler effect. This is a change in the perceived frequency and wavelength when the signal is reflected from a moving object. The ultrasound generated by the sensor reflects off the blood cells( red blood cells and other cells) and is captured by the device. This allows you to assess the direction and speed of blood flow, its linearity and uniformity. The slowing down, the appearance of turbulence( turbulence) or retrograde blood movement testify to the presence of some structural changes.

Due to a combination of the two modes, duplex scanning provides the doctor with information about the causes of blood flow disorders in the brain and the degree of blood flow deficiency.

Which vessels examine

Extracranial and some intracranial vessels are subject to examination. Of the vessels of the neck, a portion of the brachiocephalic trunk, common carotid arteries and the area of ​​their bifurcation, an extracranial part of the internal carotid artery, and external carotid arteries are examined. The temporal and supra-lateral arteries, large veins after their exit from the skull, and the venous plexus can also be studied.

When transcranial duplex scanning, the doctor examines the vessels that are in the projection of the acoustic windows( temples, orbitals, large occipital orifices).It is these parts of the skull in an adult that allow a sufficient number of ultrasonic waves to be studied. The child is also scanned through unclosed fontanels, which greatly expands the diagnostic capabilities of the method.
Transcranial duplex scanning allows to examine the intracranial part of internal carotid and vertebral arteries, cerebral arteries( anterior, middle, posterior), the main artery.

What shows duplex scanning of BSA

With the help of duplex scanning of vessels of the head and neck it is possible to identify:

• atherosclerotic lesion of arteries with narrowing of their lumen, the formation of a parietal thrombus;
• presence of pathological tortuosity( killing) of vessels;
• aneurysms of various forms and origin;
• abnormalities of the structure, branching and course of the vessels;
• vasculitis of different etiology;
• thromboses;
• vascular wall integrity disorders;
• changes in the elasticity of the vascular walls;
• presence of pathological arteriovenous or arterio-arterial shunts( places of abnormal discharge of blood into another vessel);
• violation of the compensatory and regulatory mechanism to maintain the stability of blood supply to the brain;
• degree of blood flow deficit in the narrowed areas of the vessels, the presence of pathological blood flow and changes in its uniformity and direction;
• the state of the collateral network, its functionality and the degree of compensation in case of insufficient blood flow along the main arteries.

Duplex scanning allows us to identify the causes of the decrease in the patency of the main vessels of the head and neck and simultaneously evaluate the nature and extent of the resulting consequences of this functional disturbance.

When duplex scanning of the BSA

is prescribed The study of the vessels of the head and neck is indicated for clinical signs of acute or chronic cerebral circulatory insufficiency, for monitoring the effectiveness of the therapy, with systemic thrombolysis. The basis for duplex scanning can be patient complaints about headaches, memory loss, sudden vision deterioration, fainting, head noise and dizziness, weakness in the arm and leg, difficulty in swallowing. The central paresis of the facial and oculomotor muscles, limb muscles, increasing cognitive disorders, vestibulo-atactic syndrome, bulbar paralysis revealed during examination are also the basis for diagnostic search with examination of the main vessels of the head and neck.

Duplex scanning is often included in the routine examination of individuals at risk for developing cerebrovascular diseases. This includes smokers, patients with diabetes mellitus, hypertension, obesity, identified dyslipidemia, systemic diseases. A duplex scan of the veins of the brachiocephalic basin is indicated for suspected thrombosis and thromboembolism.

investigation procedure No special preparation is required before duplex scanning. It is desirable for several days to stop taking medications that can affect the tone and patency of the vessels. This is agreed with the attending physician, as many drugs require regular admission and can not be canceled. The patient should inform the doctor of ultrasonic diagnostics about all used preparations. It is also advisable to refrain from alcohol intake, intense physical activity, bath and sauna visits the day before.

When duplex scanning of the vessels of the head and neck, the patient is lying on his back, if necessary, the doctor asks him to turn on his side. It is undesirable to talk and change the position of the body without permission. If there is discomfort in the heart, dizziness and other complaints, it is necessary to inform the examining physician about it.

During a duplex scan, the doctor presses the sensor with the contact gel applied to the skin on the side surfaces of the neck, above and behind the nape, supraclavicular and temporal areas. And when examining the supraclavicular artery and orbital vessels, the area is examined above the inner corner of the eye. When using the Doppler mode, the doctor can use functional tests to assess the state of autoregulation of the circulation. To do this, short-term compression( compression) of the carotid arteries with fingers or a sensor is performed, the head end of the couch is lowered. The doctor can also ask the patient to sit down, turn his head, often breathe, hold his breath, and strain.

In conclusion, the doctor indicates the diameter of the examined vessels, the speed and nature of the blood flow in them, the presence of constrictions( stenoses) and thrombi, pathological changes in the vascular wall. The state and thickness of the intima-media complex( CMM) is also described, and the revealed blood flow deficit is additionally indicated in percentage terms.

The interpretation of the results of duplex scanning of the vessels of the head and neck is performed by the attending physician, who also decides on the tactics of further treatment of the patient. The specialist of ultrasound diagnostics can not give recommendations on the admission of certain drugs or the need for surgical intervention.

The doctor of functional diagnostics Murat Nagaplev tells about duplex scanning of the vessels of the head and neck:

Uzi of the vessels of the neck and head

The specialist of the "Floris" medical center tells about the dopplerography of the vessels of the head and neck:

Dopplerography of the vessels of the head and neck

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