CT angiography of the head and neck vessels is considered to be an important part of a global examination of a specified area of the body. With its help, it is possible to visualize the current state of health of not only large arteries and vessels. Due to the detailed image, the specialist will be able to understand even the change in the capillary structure, if it takes place.
The main task of the modern format of the study is the assessment of blood flow by several parameters, as well as the search for possible pathologies of an innate or acquired nature. The final projection allows you to find deviations in the normal state of vessels of any size, ranging from their incorrect location and injection expansion, narrowing of the lumens. All together, this guarantees an accurate diagnosis at an early stage of development of the disease, which in the future contributes to the speedy recovery due to a verified treatment program.
Also found in the initial phase of the development of the disease are fewer complications for the body, which is especially important in the case of vascular lesions with oncological tumors of any type.
The essence of the technique
Usually, computed tomography of a selected area of the body, which doctors themselves shorten to CT abbreviations, is only one of the components of the study of the head, brain, and cervical region. The system for obtaining high-quality images of deep and shallow vessels is based on the principle of layer-by-layer scanning of soft tissues.
All the results obtained are summarized using a computer program. It gives the diagnostician a detailed projection, which is a three-dimensional model of internal organs, large vessels, and capillaries. To make the “photo” even clearer and with better resolution, experts additionally use the stage of contrasting. It provides for staining of blood, which makes blood vessels more prominent on the general background.
The basis for computer diagnostics is the involvement of the same radioactive radiation, which is used to obtain images through a standard X-ray machine. The only difference is that for angiography, experts constructed detectors that generate a reduced percentage of radiation rays.
This means that the modernized approach aimed at studying the vascular network is practically harmless to ordinary consumers. The only significant exception is pregnant women. And although for adults the dosage of radiation coming from the scanner is within the normal range, the fetus is too sensitive to the slightest fluctuations in the radioactive background.
Contraindications affect women at any gestational age. If we ignore this medical recommendation, then the risks of developing physical abnormalities of the future baby increase several times. For the rest, getting a layer-by-layer image of the bloodstream is considered safe.
Due to the fact that the blood flow to the head is closely connected with the cervical region, physicians suggest immediately conducting an examination of the two parts of the body. Such an integrated approach gives refined results, which qualitatively affects the subsequent construction of the future treatment. It often happens that the cause of cerebrovascular insufficiency is not the head vessels that cope with the tasks set for them to be "excellent." The problem lies in the pinching of the arteries or veins located between the cervical vertebrae. This situation occurs quite often, especially among people leading a sedentary lifestyle.
The most important advantage of this non-invasive method of checking the state of the vessels is the ability to conduct the study several times, if it was not possible to obtain the required clarity from the first take. Failures of this kind usually occur due to the involuntary movement of the patient, which is located directly under the apparatus arch.
The technique, when carrying out the manipulation correctly, reveals to the specialist the following aspects of the victim’s health:
- the anatomical location of the vessels in the head, neck;
- the structure of the vascular network;
- the presence of atherosclerotic plaques;
- the size of the veins, arteries and their lumen;
- the presence of vascular constriction and the source of the problem;
- presence of collaterals.
Since the three-dimensional projection covers a large area of the body under study, an experienced doctor will be able to consider not only the focus of the disease, but also complications spreading around the point of injury.
Usually a cardiologist or a vascular surgeon directs the patient to the diagnostic room. But there are options when doctors from related specialties prescribe angiography to eliminate the risks of extensive damage. Among such doctors emit phlebologist and vertebrologist.
The underlying reasons for conducting such a comprehensive review are the following diseases or suspicions about them:
- changes in the carotid artery;
- kink syndrome;
- swelling of the neck;
- painful syndrome in the cervical vertebrae;
- angiopathy, as an independent diagnosis or consequence of the development of diabetes;
- tumors of benign or malignant type;
- control slice after local surgery;
- squeezing of vessels with tumors of various etiologies or scar tissue.
To determine all of the above allow additional tests such as classical ultrasound, blood biochemistry. Also, before sending to the layer-by-layer scanning, the treating expert should listen to the accumulated complaints from his ward and study the history from the medical record.
Having gathered together all the information, the doctor will make a verdict about the malnutrition of the brain and problems with its blood circulation, which is caused by incorrect vascular activity. CT angiography will help to find the source of all ills.
Who is contraindicated for examination?
If you put aside the most important prohibition for testing - pregnancy, then all other contraindications can be classified as relative. In practice, this means that the doctor decides to ignore them individually, relying on the advantage over the potential harm.
These relative contraindications include:
- renal failure;
- heart failure;
- endocrine problems;
- allergic reaction to iodine in its pure form or seafood in particular.
All of the above affects only situations where, in addition to the traditional part of the examination, the patient was prescribed a stage of contrast. But as for a thorough study of the state of the vascular grid, it is almost never without it, and contraindications are relevant for almost all patients.
The main danger, if desired, to hedge with the help of contrast are the iodine-containing components of the solution for the procedure. If the victim has an allergy to them, then the classic remedy is replaced by rarer analogues.
If the victim is not aware of whether he has a pronounced response of the body to a microelement, then at the preparation stage he will be asked to make an allergic test.
Separately, situations are considered when the patient is still breastfeeding the child at the time of the test. To avoid negative consequences for the young heir, doctors insist on refusal to lactate at least 36 hours after the manipulation. During this time, most of the harmful components of the solution for contrast will be derived naturally by the kidneys. To speed up this process, you need to drink more fluid.
Also, the appointment of a CT scan to young children, the elderly, patients with uncontrolled movements will be questionable. The latter cover a group of people with psychological and nervous disorders. The most important condition for obtaining a clear projection is to maintain complete immobility throughout the procedure. Otherwise, the analysis will have to be redone.
The final relative contraindication is a short time interval between CT and x-ray examination, or contrast. Doctors recommend keeping the interval for about four weeks to make an appointment again.
Preparation and technology of
Angiography does not require any substantial preparation. The most important thing is to abstain from eating about four hours before the scheduled time of reception.
Care should also be taken to choose for examination comfortable clothing that does not contain any metal components. Any decorations, as well as gadgets should be left in the laboratory, so that their radiation does not spoil the clarity of the picture. For a while, even dentures and hearing aids will have to be removed, if they have a place to be.
The procedure takes about half an hour, if the appointment provides for the introduction of contrast. After the solution is injected with an intravenous injection or drip, the patient will be asked to lie down on a medical couch. Since you have to lie still, for the convenience of preserving the posture, a roller is placed under his head. And for fixing the position of the used straps.
After activating the equipment, the couch is sent under the arch of the scanner, which will rotate while taking pictures. Unlike MRI, which lasts for quite a long time, the computerized format for examining blood vessels takes much less time, which pleases people suffering from claustrophobia.
During the operation of the detectors, they can emit sound signals that should not be frightened, so as not to accidentally flinch.
The exact time of the survey can only be called a diagnostician, since it depends on the specific equipment model. New versions work a little longer, since the step of their "photographing" is only 0.5 mm. For increased clarity you have to pay a longer wait.
Usually, the test results are handed to the patient during the next hour, or the next day they are sent directly to the attending physician. The conclusion is not only a projection provided on an electronic medium, but also accompanying information revealing the state of health of the victim.
There are no contraindications at the end of the procedure. Doctors simply advise to drink more to speed up the withdrawal of iodine-containing drug.
The wide diagnostic capabilities of the new generation equipment, taking into account the minimum radiation load, make the technique absolutely justified. The data obtained are carefully studied by the injured’s doctor in order to deal with the lesion focus.
The most important point that the expert draws attention to is the possible displacement of the problem vessel to the area of the lesion. If this was fixed, then the search begins for secondary signs indicating the severity of the destructive process. It can be both affected adjacent capillaries, and the onset of inflammation in the surrounding soft tissues or even bone structure.
If the disease is at the start-up stage, then a specialist may additionally order a classical computed tomography of the cervical spine or other suspected affected areas.
By enhancing the illumination of the inflamed area due to the contrast, it turns out to recognize the exact location of the site of the lesion, which helps to further establish the correct treatment. This can be either alternative therapy or surgery.
In this case, the experienced doctor makes the final diagnosis after studying the full history, other test results and the patient's current complaints.