Uzdg of paired vessels of arteries and veins. Is preparation necessary? How is an ultrasound examination of the neck performed?

Vascular ultrasound– a study that displays the structure and characteristics of blood flow in peripheral and main vessels, in arteries and veins located in internal organs. Doppler ultrasound and duplex angioscanning are possible. Depending on the diagnostic tasks, the vessels of the neck and head, arteries of the extremities, and veins are examined lower limbs, abdominal aorta with branches, inferior vena cava and branches, the ankle-brachial index is determined. The cost of ultrasound depends on the chosen method and the scope of examinations.

Preparation

There is no mandatory preparation for vascular ultrasound. If research is carried out abdominal aorta, 3 days in advance it is recommended to stop eating foods that cause flatulence. It is worth excluding legumes, baked goods, confectionery and carbonated drinks, reduce the amount of fresh fruits and vegetables. The procedure is best performed after 8-12 hours of fasting. To obtain informative results from examining the vessels of the brain and neck vessels, on the day of the examination it is necessary to refrain from coffee, strong tea, alcohol and other substances that alter vascular tone.

What does it show

Doppler ultrasound allows you to assess the patency of the vessel, determine the direction and speed of blood flow. There is no visualization of the vessels; in case of deviations from the norm, it is impossible to clarify the cause. Duplex scanning displays the anatomy of the vessel on the monitor: thickening of the walls, tortuosity of the course, blood clots, plaques, developmental anomalies, postoperative joints. The study also provides information about the speed and direction of blood flow. With triplex scanning, the image of the vessel is colored. In addition to assessing blood flow and visualizing the structure of the vessel, it is possible to more accurately judge the direction of blood flow, identify obstructions in patency and determine their cause. Vascular ultrasound detects the following pathologies:

Vascular atherosclerosis. Ultrasound signs of atherosclerosis are a decrease in the elasticity and firmness of the vessel, thickening of the intima media layer, changes in the uniformity of blood flow, and the presence of atheromas. Stable plaques are visualized as homogeneous hyperechoic structures with a clear contour; unstable – as homogeneous hypoechoic foci; calcified - as heterogeneous formations with hyperechoic inclusions.
Arterial hypertension. Ultrasound is used to diagnose the causes of hypertension. Increased blood pressure may be the result of atherosclerosis (plaques are detected), stenosis (narrowing of the lumen is recorded), and renal circulatory failure. Characteristics Ultrasound images - thickening of arterial walls, increase in pulse wave speed from carotid to femoral artery up to 12 m/s or more, ABI less than 0.9.
Cerebrovascular accident. Circulatory disorders in the brain include strokes, transient ischemic attacks, and insufficient blood supply to the brain. Ultrasound reveals high arterial pressure, impaired elasticity of the vascular wall, its protrusion (aneurysm), formation heterogeneous structure(thrombi), kinks and narrowing of the lumen of blood vessels.
Phlebeurysm. The ultrasound method allows us to determine the cause varicose veins, assess the degree of blood flow disturbance. Diagnosed uneven expansion vascular lumen, change in the trajectory of superficial veins, hyperechogenicity of the walls, insufficiency of the valve apparatus.
Thrombophlebitis and deep vein thrombosis. In patients with thrombophlebitis, inflammatory changes and blood clots of the saphenous veins are detected. In case of deep vessel thrombosis, the nature of the thrombus is determined. A floating thrombus is characterized by mobility of the apex, heterogeneous echostructure, and uneven surface. Embologenicity is higher with reduced echogenicity or anechoicity of the clot. An occlusive thrombus causes blockage of a vessel, while a parietal thrombus locally reduces the speed of blood flow.

Ultrasound data indicate the nature of vascular damage, but cannot be used in isolation to make a diagnosis. Ultrasound examination is part diagnostic process, complements and confirms the results of the inspection, survey and laboratory research blood.

Advantages

Compared with X-ray angiography, CT and MRI of vessels, sonographic methods for studying vessels are more accessible, allow you to quickly obtain results, have no contraindications and side effects associated with the administration of contrast or radiation exposure. The disadvantage is that there is not always sufficient information content, the impossibility of research small vessels. Wide use Vascular ultrasound has become popular due to its non-invasiveness and low cost.

Duplex scanning is a type diagnostic study. This greyscale echography includes color coding and spectral Doppler analysis. Today, duplex scanning of the head and neck is considered the main diagnostic method when identifying various pathologies systems of blood channels in these zones. Next, let's take a closer look at what it is this procedure and for what diseases it is prescribed.

General information

Duplex scanning is a procedure that combines the ability to visualize the lumens of blood channels and surrounding tissues in 2-dimensional gray scale echography (B-mode) and simultaneous assessment of hemodynamics using Doppler technologies. According to the results, the elasticity and stiffness of the walls are analyzed, functional state endothelium, violation of integrity (dissection), presence, prevalence and nature of changes in the structure and thickness of the wall. During the study, a specialist can identify intraluminal formations, their location, echogenicity, and extent. Duplex scanning of vessels allows you to assess the degree of lumen patency and changes in diameter. During the procedure, the geometry of the blood channels is analyzed. In particular, deformations, deviations from the normal anatomical trajectory, anomalies of origin, branching and length are identified. Duplex scanning of vessels allows you to obtain information about intraluminal flows. Information is obtained based on processing of the Doppler reflected signal using the Fourier (fast transform) method.

Information collection methods

Information during transcranial and conventional scanning may appear in the form of Doppler spectra or color cartograms. In the latter case, based on the research data, the specialist receives qualitative information about the blood flow, its nature (turbulent, laminar), defects in filling out cartograms, etc. The spectral mode allows one to quantitatively characterize intraluminal flows. In other words, the study makes it possible to objectify the absence or presence of hemodynamic disorders and determine the degree of their severity. The obtained diagnostic information is based on the assessment of speed indicators and various calculated indices, which indirectly characterize the degree of peripheral resistance, as well as the tone of the wall of the blood channels.

Extracranial examination: indications

Duplex scanning of the vessels of the head is prescribed for:

Duplex scanning of veins is carried out if there is clinical signs thrombosis

Benefits of the study

Duplex scanning is characterized by high resolution, non-invasiveness and the possibility of multiple repeat procedures. Thanks to this, research is considered an indispensable tool in clinical neurology. Duplex scanning allows for full preventive screening in the asymptomatic population. Using this research method, the possibility differential diagnosis are expanding significantly. Duplex scanning of neck vessels allows us to identify medium and small stenoses of the carotid canals. Based on this, it can be stated that the study can be used as a basic screening method in individuals without showing clinical signs of cerebrovascular disorders.

Transcranial examination: indications

This type of study is prescribed if:

Objectives of the study

Duplex scanning of the vessels of the head not only helps to identify occlusive and stenotic pathology of the brain, but also allows one to assess its hemodynamic and pathogenetic significance. The examination reveals:

A complex of violations caused by systemic diseases blood channels.
Anomalies in the development of blood vessels, aneurysms, malformations, cerebral vasospasm, anastomosis, circulation disorders.
Early (preclinical) signs of systemic disease.

Duplex head scanning allows for performance monitoring therapeutic activities. During the study, it is possible to assess the reserve capabilities of the cerebral circulatory system, establish the likely etiological role of the detected pathological process or symptom complex in the genesis of the manifestation of one or more clinical syndromes for a specific patient. The examination also makes it possible to determine the functions of central and local mechanisms regulating the tone of blood channels.

Duplex scanning of the neck

The mandatory scope of the survey includes several areas. In particular, these include:

If detected indirect signs violations in the V3 segment, echolocation can be performed in this area.

Duplex scanning of the lower extremities: indications

An examination is prescribed when:

Swelling in the ankle area.
Discomfort and pain in the lower legs when moving and at rest.
Convulsive twitching, pulling sensations in the fingers.
Heaviness in the lower extremities.
Fading or darkening skin, redness or induration.
Spider veins, pronounced changes in the saphenous veins.
Trophic ulcers.

Duplex scanning of the veins of the lower extremities is also recommended in the absence of pulses in the legs.

Description of the procedure

Duplex scanning of the veins of the lower extremities does not require special training. Clothing should be chosen so that the specialist has access to the areas being examined. Before duplex scanning of the veins of the lower extremities is performed, the patient lies down on the couch. Using special equipment and a sensor with gel applied to it, the doctor guides through the main blood channels of the legs. The gel enhances the transmission of information to the device. Additionally, duplex scanning of the veins of the lower extremities can be performed in a standing position.

Features of the study

When conducting duplex scanning vessels of the head, low frequency radiation is used. This is due to the existing obstacles in the path of the rays in the form bone elements skulls Using low frequencies Visualization of the vascular walls and assessment of the condition of the lumens becomes impossible. The information obtained is indirect. The information is based on the analysis of color cartograms of the flows of intracranial veins and arteries, as well as Doppler spectra. In this regard, against the background of a transcranial study, it is impossible to assess changes and diagnose processes that are not accompanied by the formation of systemic and local hemodynamic disorders. Due to the different thickness of the bone elements of the skull, which causes unequal permeability of ultrasonic radiation, echolocation is performed in specific areas. They are called "ultrasonic windows". The quality and volume of information obtained during transcranial scanning depend on their severity. The main limitations may be due to a significant deterioration in ultrasound visualization against the background of a decrease in the acoustic ability of the bone elements of the skull.

Additional features

During scanning of extracranial sections of the brachycephalic arteries, differential features, characteristic of stenosing atherosclerosis, microembolism, thrombosis, vasculitis, angiopathy. With a transcranial study, it is possible to verify occlusive or stenotic injuries and determine their severity without specifying morphological equivalents. The examination also allows us to identify specific phenomena characteristic of a failure of autoregulation of blood flow in the brain, cerebral vasospasm, and others. If an atherosclerotic lesion of a stenotic type is detected in the carotid arteries, the echostructure of the plaque and the degree of lumen patency impairment for each damaged vessel are assessed.

Examination of the vertebral blood canals

Due to the presence of anatomical features of their location, visualization of the arteries is possible only in fragments. They are available for monoplanar examination. This significantly limits scanning capabilities for diagnostics. various diseases. Thus, with high reliability, with low quality of visualization, only stenotic lesions with narrowing of the lumens of more than 40-50% in diameter, located in accessible areas, are determined. Echostructural analysis of formations inside the lumen, as a rule, is not performed. This is due disabilities for visualization of the walls of blood channels. Definition functional changes in the diameter of the vessels is carried out using stress testing. Objective specific ultrasonic signs for extravasal compression in the vertebral blood canals in the area of the transverse processes of the vertebral elements upper section there is no column in the area of the craniovertebral joint.

Duplex diagnostic criteria used in everyday practice are indirect in nature and mandatory require confirmation by methods that make visualization possible. These include, in particular, angiographic examinations in the background or with loading functional tests. Scanning of the jugular veins (external, internal), as well as vessels in the vertebral column venous plexus carried out in case of suspected thrombosis in them.

Diagnostic value

Clinical significance of duplex blood circulation indicators obtained in Doppler spectral mode from the lumens of the vascular collectors listed above, as well as their role in assessing pathological changes cerebral hemodynamics in other cases is considered very doubtful. In this case, the variability of blood outflow from the cranial cavity when the patient changes body position, the variability of the structure of the blood channels themselves, the synchronization of the flow with breathing, as well as the easy compressibility of the lumens are taken into account.

Monitoring

Using duplex scanning, it is possible to monitor the course of blood flow and determine vascular reactions in the area of damage, both against the background of selective and systemic thrombolysis. Stabilization of the flow in the affected area or its acceleration in the lumen, a decrease in intensity or the disappearance of collateralization are considered objective signs of the effectiveness of the therapy used. In the absence of positive dynamics when assessing the echographic picture, the specialist can conclude that the treatment the patient is receiving is ineffective. In practice, there are often cases of inconsistency between clinical effect and the success of revascularization.

Finally

Like any other ultrasonography, duplex scanning is an operator-dependent method. And - to a certain extent - subjective. The success of using a range of imaging capabilities in clinical neurology, in addition to the skills and experience of the specialist operator, will largely depend on quality characteristics used when inspecting equipment. As a result, despite all controversial diagnostic cases during planning surgical intervention on cerebral vessels The reference method for ultrasound examination in angiology is the radiocontrast method and its variations, recognized in practice as the “gold standard”.

Dopplerography is a method of studying blood flow in large and medium-sized human vessels, based on the use of the Doppler effect. This examination is used during pregnancy to assess the functioning of the placenta and uterine arteries.

In non-pregnant patients, the method is used to clarify the nature and extent of circulatory disorders in any not very small vessels.

In terms of the sensations for the patient and the nature of the preparation, Doppler ultrasound does not differ from conventional ultrasound.

What is the Doppler method?

To obtain information about the speed and nature of blood flow, pressure, direction of blood movement in the vessel and the degree of its patency, the same ultrasound is used as during a “regular” ultrasound.

It only emits it and receives it back with a special sensor that operates on the basis of the Doppler effect.

Given physical phenomenon lies in the fact that the frequency of ultrasound reflected from moving objects (blood cells) changes greatly compared to the frequency of the ultrasound emitted by the sensor.

The device does not record the oscillation frequency itself, but the difference between the initial and reflected frequencies.

Moreover, signal processing not only allows one to calculate this speed, but also to see the direction of blood flow (from or to the sensor), and to evaluate the anatomy and patency of the vessel.

For vessels different localization Sensors with different frequencies of emitted sound are used.

Doppler ultrasound (USDG) are synonyms for the name of this study (that is, “I had a Doppler ultrasound” or “I had an ultrasound scan” are equivalent statements).

The method is safe and painless for humans and can be performed as often as desired, but only according to indications determined by a specialist.

Fun fact: in nature this effect to determine the speed of a moving object is used the bats and dolphins.

Indications for the study are as follows:

Why is Doppler sonography needed? To assess blood flow in huge quantities various vessels person. The doctor prescribes this study if, based on complaints and the nature of the development of the disease, it is assumed that the patient has a vascular pathology.

In this case, the attending physician needs to determine which vessel is affected, how affected it is (this determines the therapy), how it will affect health, and what complications may arise.

For example, fetal Doppler is performed in the following cases:

mother suffers diabetes mellitus, hypertension, anemia or systemic diseases
The baby's size is not appropriate for its gestational age
mother has Rh negative, child – positive
several fruits develop
oblique or transverse position of the baby in the uterus
umbilical cord entwined around baby's neck
hydramnios or polyhydramnios
gestosis
chromosomal diseases of the fetus.

Such an ultrasound scan during pregnancy (that is, Doppler ultrasound) allows you to find out from the 23rd week whether the baby is suffering from a lack of oxygen.

What is CDK

Color Doppler mapping (CDC) is one of the subtypes of ultrasound based on the Doppler effect. It also “works” with the assessment of blood flow in the vessels.

This study is based on a combination of conventional black-and-white ultrasound and Doppler assessment of blood flow.

In the color flow mode, the doctor sees a black-and-white image on the monitor, in a certain (studied) part of which data on the speed of movement of structures is displayed in color.

Thus, shades of red will encode the speed of blood flow directed to the sensor (the lighter, the lower the speed), shades blue color– speed of blood flow directed from the sensor. A scale is displayed next to it, indicating which speed each shade corresponds to. That is, veins are not indicated in blue, and arteries are not indicated in red.

Color Doppler imaging visualizes and analyzes:

direction,
character,
blood flow speed;
cross-country ability,
resistance,
diameter of the vessel.

Diagnoses:

degree of thickening of the vascular wall
mural thrombi or atherosclerotic plaques(can tell them apart)
pathological tortuosity of the vessel
vessel aneurysm.

This study helps not only to detect specific vascular pathology. Based on the data obtained as a result, it is possible to distinguish a benign process from a malignant one, determine the tendency of the tumor to grow, and distinguish some formations.

The study also allows us to distinguish some volumetric formations. Thus, with the help of mapping, it is possible to distinguish a stone soldered to the wall of the gallbladder from its polyp (blood flow will be determined in the latter, whereas there is none in the stone).

Doppler mapping performed on vessels abdominal cavity, helps in diagnosing those pains in the abdominal cavity that arise due to insufficient blood supply to the intestines (this pathology cannot be determined by any other method).

Doppler ultrasound differs from color doppler ultrasound in that there is no color designation of blood flow velocities. This study is the same as Dopplerography, only the blood flow is assessed on the monitor, the recording is not recorded graphically.

Preparing for a Doppler study

Depends on which vessels need to be assessed. So, to study the vessels of both the upper and lower extremities, head or scrotal organs, there is no need to prepare for the procedure.

Dopplerography during pregnancy is also performed without preliminary preparation. It is advisable only to undergo the study a couple of hours after eating, since recent admission nutrients to the baby somewhat changes the picture of real blood flow.

How the research is carried out

Duplex scanning of the vessels of the head and neck is performed in a lying or sitting position.
The patient's head is rotated so as to clearly expose the area of the vessels being examined.
A gel is applied to the neck, along which the sensor moves.
Doppler of other areas is also done through the skin, onto which a special gel is applied. A Doppler ultrasound sensor is not inserted into the cavity (intravaginally, transrectally).

What indicators are important for assessing blood flow

Dopplerography is interpreted using a number of indicators, which are assessed in arterial and venous vessels, and then compared with the normative values for this particular vessel.

In addition, the doctor knows how a given vessel should pass normally, where it has bends, where it flows into more large vessel. The location and tortuosity of the arteries in a particular person is compared with normal values.

The following parameters of arterial blood flow are assessed:

Blood flow speed. Each vessel has its own speed standards.
The systole-diastolic ratio. This is the ratio of the maximum and minimum blood flow speed. The first occurs in the vessel during systole - the second - in diastole.
Pulsation index (PI) – the ratio of the difference between the maximum and minimum speeds to average speed in a vessel.
The resistance index (RI) is obtained by dividing the difference between systolic and diastolic velocity by the systolic velocity.
The thickness of the vascular wall (this parameter is designated as the thickness of the intima-media complex). In almost all vessels the norm for this indicator is 0.9-1.1 mm.
Vessel diameter. Compares with standard indicators.

The price of Doppler ultrasound depends on which vessels need to be examined. Thus, the price of ultrasound examination of the scrotal organs is 1200-2000 rubles, Doppler of the vessels of the lower or upper limbs– 1200-2100 rubles. Scanning the blood vessels of the head costs 1600-4000 rubles. USDG ocular vessels– 350-2040 rubles. Dopplerography of the fetus – 1000-2500 rubles.

Thus, Doppler sonography is an informative method for diagnosing pathology. huge amount human vessels. This study is being conducted as regular ultrasound, is safe and painless. There is often no alternative to this diagnosis.

IN modern medicine in area vascular pathologies there are many different therapeutic techniques. However, the treatment of any disease requires complete and thorough examination. Diagnostics of blood vessels is effectively carried out using ultrasonic methods research, this is due to the structure and structure of blood vessels. The concept of ultrasound is no longer new to many.

Ultrasound examination can be carried out using Doppler ultrasound (USD), duplex ultrasound scanning (USDS), and color Doppler mapping (CDC).

Diagnostics using ultrasound scanning

One of the simplest and available ways The study of venous and arterial patency is Doppler ultrasound. Ultrasound ultrasound is based on the Doppler effect, that is, to obtain the necessary data, changes in reflected sound waves from moving blood cells are recorded. The Doppler ultrasound method is prescribed when it is necessary to determine vascular patency, either to obtain an assessment of blood flow, or to identify pathologies of the venous valve.

When performing Doppler ultrasound, veins and arteries are not visible; the blood flow velocity and patency are assessed based on the obtained Doppler effect values. Based on the results of the ultrasound examination, headaches are successfully diagnosed, hypertonic disease, phlebeurysm . But if identifying impaired vascular patency is done easily, then establishing the causes of such pathology using Doppler ultrasound is very difficult. This is due to the fact that this diagnostic method does not allow visualization vascular walls and their possible curvatures, affecting the speed and quality of blood flow.

Initially, the images shown by the ultrasound device were made in a flat and thin projection of the organ being examined. Modern diagnostic medicine uses equipment that allows obtaining three-dimensional images of organs in real time and in motion.

Dopplerography is prescribed to determine the patency of blood vessels and obtain blood flow characteristics

Diagnostics by ultrasonic scanning

Ultrasound duplex scanning - more complex diagnostic technique, is distinguished by its combination of B-mode and the Doppler effect. The use of B-mode allows you to visualize the veins and arteries being studied and study the condition of the surrounding tissues. The study of blood flow in the vessels is carried out using color mapping using the Doppler method or spectral analysis techniques.

As a result of the study and subsequent computer processing of the data, it is possible to obtain readings presented in the form of a Doppler spectrum or a color cartogram of blood flow. The cartogram is obtained using various color mapping technologies and, in fact, it is a “cast” of the cross section of the vessel under study. During duplex examination vessels, an image of the vessel is displayed on the monitor screen, which allows you to make a visual assessment of the patency of a vein or artery and find the reason that caused a decrease in the speed of blood flow. Using ultrasound scanning, the following pathological vascular conditions can be identified:

development of vascular stenosis, thickening of vascular walls;
the occurrence of various anomalies during the passage of blood vessels through tissue;
cholesterol plaques and blood clots in veins and arteries;
vascular junctions after operations.

Difference duplex study and Doppler ultrasound is that ultrasound combines two research functions. Doppler ultrasound allows you to assess the speed characteristics of blood flow in the vessels, and B-mode makes it possible to identify anatomical features the structure of a vein or artery, due to the visualization of the vessel itself on the monitor.

Advantages of the USDS technique

Using ultrasonic scanning, you can easily determine most pathological abnormalities in the normal course of blood vessels, for example, tortuosity or deformation. In addition, this is the main method for studying changes in vascular lumens, determining the presence cholesterol plaques and blood clots. This type of ultrasound can provide visualization and assessment of the blood flow characteristics of the entire vascular system, including large main trunks and small organ subcutaneous vessels.

Exploring ultrasound large veins and arteries, it is possible to create a clear and reliable picture of the existing structural pathologies of the vascular walls at the very first stages of the development of the disease. Thus, non-stenotic atherosclerosis and diabetic angiopathy. Pathological processes accompanied by intraluminal vascular lesions, which impair patency or reduce the speed of blood flow, for example, blood clots and plaques, also do not cause difficulties for ultrasound diagnostics.

Duplex scanning combines two research methods and allows you to identify most pathological processes in vessels

Diagnostics using the color flow method

When carrying out triplex scanning, the above-mentioned techniques are carried out and color visualization of the vessels and blood flow in them is added. Scanning in this way allows for a more informative examination, with high accuracy determine vascular patency and the degree of stenotic vascular lesions. In other words, CDK is a combination of Doppler ultrasound diagnostics and duplex scanning, combined with additional research internal vascular lumen in color visualization mode.

Indications for diagnostics

The appearance of certain symptoms often becomes the reason for prescribing an ultrasound examination:

the appearance of headaches and dizziness;
dysfunction of the vestibular apparatus;
feeling of heaviness in the head;
the appearance of tinnitus and flashing black dots before the eyes;
causeless loss of consciousness;
disease varicose veins veins;
development of edema of the upper and lower extremities;
frequent seizures;
sharp decrease in vision.

The development of edema of the extremities is a good reason to prescribe a Doppler examination or duplex scanning of blood vessels

Pathological conditions of the human vascular system, in which it is mandatory to carry out ultrasound diagnostics one of the following ways:

cerebral aneurysm;
illnesses chronic accompanied by the development of vascular insufficiency;
bruises cervical region spine and head injuries;
venous diseases;
stroke conditions;
reconstructive surgery on the spine;
state of vegetative-vascular dystonia;
atherosclerotic lesions;
cervical osteochondrosis.