In this article we will tell you what it is - TCD, and how the study is conducted.
Oxygen and other vital elements through the arteries and veins enter the cells of the brain and other organs. Nutrient deficiency negatively affects the state of the human body. Ultrasound dopplerography (dopplerographic examination of cervical vessels, ultrasound scan, doppleroscopy of cerebral vessels, dopplerography of cerebral vessels, transcranial dopplerography) is a non-invasive method for blood flow analysis. Such a procedure is advised by a neurologist to prescribe the necessary treatment or undergo additional studies.
The essence of dopplerography
This technique is highly informative, with its help many brain disorders are diagnosed. Ultrasound Dopplerography (Doppler ultrasound) or TCD of the vessels of the head and neck combines research based on the Doppler effect and ultrasound diagnostics. From a technical point of view, Doppler ultrasound simplification can be described as follows: reflected high-frequency sound waves affecting blood vessels contribute to visualization of the structure of veins and arteries, while Doppler ultrasound of the head vessels reflects the movement of red blood cells at a particular moment. Using a computer, two ready-made images provide an accurate picture of the movement of blood. Due to the color coding, the device provides a full visualization of blood flow and the characteristics of existing diseases.
Study Modes
The study uses several modes, which depends on a specific area:
- scanning of the main arteries, which allows the study of vascular blood flow;
- duplex arterial and venous scanning, giving the specialist a color two-dimensional sketch, on which the state of the vessels in the neck, cranium, and both lobes of the brain is fixed;
- triplex scanning, which complements the first two studies.
To display the comprehensive state of the vessels of the brain, the main veins and arteries that provide blood flow, these modes are used simultaneously. Thanks to the TCD of the vessels of the head and neck , the clinical picture is reliably obtained on the computer monitor using the radiation of an ultrasonic wave that penetrates the blood vessels, is reflected from the blood red cells depending on the speed and direction in which they move. The reflected waves are caught by special sensors and converted into an electrical signal, which forms a sketch in the dynamics. If there are blood clots, narrowing of the gaps and spasms, the course of blood changes. This immediately gets a fix on the screen. To examine the veins and arteries located in the brain, a sensor is installed on the bones of the skull, which have a minimum thickness.
Triplex study
Often patients ask a question: how is triplex examination of cerebral vessels carried out, what is its essence and purpose? With ordinary Doppler ultrasound, the doctor evaluates only the patency of the vessels, with duplex scanning, the vascular structure, speed and intensity of blood flow are determined. Triplex TCD of the vessels of the head and neck allows you to examine the structure of blood vessels, as well as the dynamics of blood movement, to obtain a large-scale picture of the patency of vessels in color.
Who needs an examination?
To understand that in the brain there is insufficient nutrition of cells, you need to pay attention to such symptoms:
- imbalance, shaky gait, problems during movement;
- decreased hearing and visual acuity;
- violation of speech articulation;
- frequent headaches;
- noise in ears;
- vomiting and nausea, not caused by an upset digestion;
- dizziness, especially when bending;
- fainting
- change in taste
- insomnia;
- memory loss, impaired concentration of attention;
- chilliness, swelling and numbness of the arms and legs;
- decreased sensitivity in certain areas of the body.
Dopplerography of the brain of the head is indicated for patients with some chronic diseases. A specialist can schedule an examination for people who:
- suffer from diabetes mellitus and vegetovascular dystonia;
- smoke
- are overweight;
- suffered a heart attack or stroke;
- have osteochondrosis of the cervical spine;
- Feel very tired when walking, running and small physical exertion;
- have heart palpitations, if there is a chance that the detached thrombus clogs the artery that feeds the brain;
- have a pulsating focus in the neck.
In addition, a study can be prescribed before surgery on the heart, as well as children with mental disorders.
Based on the patient's complaints, the neurologist can determine where the blood flow in the body was impaired.
What is determined?
TCD of the vessels of the head and neck helps:
- determine the narrowing of the arterial lumen and the severity of the diagnosed disorder;
- identify the strength and speed of blood flow in the main arteries ;
- detect cerebral aneurysms;
- to assess the condition of the arteries of the spine;
- analyze the state of the vessels during compression, bending and deformation;
- identify disorders that result from the accumulation of atherosclerotic plaques or the formation of blood clots;
- find the causes of headaches that can be impaired circulation, high intracranial pressure and angiospasm.
Patient preparation
The patient should refrain from drinking coffee, tea, alcohol and energy drinks a day before the implementation of ultrasound and TCD of the vessels of the head and neck. It is undesirable to smoke at least four hours before the procedure and take medicines. The meaning of such restrictions is that there is no unnecessary load on the blood vessels and, in general, on blood pressure. When undergoing examination by a child, it is necessary to ensure his emotional and physical peace.
What is important to understand?
The patient must understand that the study is completely painless, he needs to fulfill all the requirements of the doctor, not to make unnecessary movements and not talk. The specialist may ask the small patient to hold his breath or start breathing quickly. It is advisable to feed children up to one hour before the study and ensure sleep. There are no restrictions on the use of food on the eve of the procedure, but it should not be eaten immediately in front of it, because when the food is digested, the blood flow to the head decreases, and the study may be distorted. For hygiene purposes, you need to take a towel with you.
Features
Occupying a horizontal position on the couch, the patient lies on his back. Dopplerography of the vessels of the head and neck with doppler lasts from 20 to 35 minutes. The specialist applies a special gel on the body to facilitate the sliding of the sensor and avoid interference. First, the neck is analyzed by smoothly moving the sensor up the neck to the lower jaw. Put it on the points at which the medium and large veins and arteries are located. The patient is asked several times to hold his breath, and also to change the position of the body in order to accurately assess vascular tone. After that, the device is switched to a color mode to detect vascular pathologies, areas with impaired blood flow and blood clots.
The study is carried out on the back of the head, temples, and scalp. During it, loads on the vestibular apparatus, light flashes, sound stimuli, head turns, breath holding and blinking are used. Vascular Dopplerography of the vessels of the brain of the head does not bring pain. When the procedure ends, hygiene procedures will be required - remove the remaining gel.
How is data decrypted?
The interpretation for ultrasound and Doppler ultrasound of the vessels of the head and neck consists in a comparative analysis of the artery with specific norms for a number of parameters: diameter; wall thickness; resistance indices; features of the symmetry of blood flow; systolic peak velocity. Assessment of veins is made by the vascular diameter, the nature of the blood exchange, as well as the state of the walls of the veins. If the results are normal, then:
- between the vessels there will be a clearly visible and free clearance;
- the thickness of healthy arterial walls should be about one centimeter;
- in areas in which there is no branching of blood vessels, turbulent blood flow is absent;
- there should also be no arteriovenous malformations;
- when squeezing the vessels together, an additional examination will be required;
- if any area is abnormal, the doctor indicates an alphanumeric abbreviation;
- knowing all the signs, the neurologist easily deciphers the information received and prescribes the appropriate therapy.
Contraindications and assumed risks
There are no absolute contraindications that prohibit the procedure. Limitations are the patient’s serious condition and other factors that prevent the patient from lying down (chronic heart failure, exacerbation of bronchial asthma). Dopplerography is absolutely safe for the human body, does not carry radiation. This procedure has no age restrictions. It is carried out by the elderly, infants, nursing mothers, pregnant women. During pregnancy, the doctor can send for a study, if there is a possibility of circulatory disorders in the placenta.
TKDG DS vessels of the head and neck are allowed to be carried out repeatedly. Due to its harmlessness and high accuracy, the technique is used to control the ongoing treatment. In addition, it is prescribed for the prevention of serious diseases.
During the study, certain difficulties may appear: it is more difficult to assess the condition of small vessels than large ones; it happens that the cranial bones interfere with the full analysis of the state of all the vessels of the brain. Results often depend on specialist qualifications and instruments. Often, transcranial dopplerography (TCD) is used instead of angiography.