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CT angiography of the vessels of the head and neck is considered an important part of the examination of this area of the body. With its help, it turns out to visualize the current state of health not only of large arteries. Due to the detailed image, the radiologist will be able to understand even the changes in the vascular structures of a smaller caliber, if they take place.
The main task of this modern study is the assessment of blood flow in several parameters, as well as the search for possible pathologies of a congenital or acquired nature. The final visual picture allows you to find deviations of vessels of any size, starting from their incorrect location and pumping by expansion or narrowing of their lumen. All these data together guarantee an accurate diagnosis at an early stage of the development of the disease, which in the future contributes to a speedy recovery due to a correctly prescribed treatment program.
Also, diseases detected at the initial stage of development have fewer complications on the body, which is especially important in the case of vascular damage with severe changes of any type.
The essence of the technique
Usually, computed tomography of the examined part of the body, which doctors themselves abbreviate as CT, is only one of the components of the study of the head, brain and cervical region. The technique for obtaining a highly informative picture of deep and shallow vessels is based on the principle of layer-by-layer scanning of tissues using X-rays.
All data obtained are summarized using a computer program. It gives the radiologist a detailed visualization, which is a three-dimensional model of the internal organs, large vessels and capillaries. To make the picture even clearer and with good contrast, the contrast stage is additionally used. It involves the introduction of a contrast agent into the blood, which makes the vessels more prominent against the general background.
The basis for computer diagnostics is the same radioactive radiation that is used to take pictures through a standard X-ray machine. The only difference is that for angiography, scientists have designed detectors that generate a reduced background of radiation rays.
This means that the modernized approach, aimed at studying the vascular structure, is practically harmless to ordinary consumers. The only significant exception is pregnant women. And although for adults the dose of radiation received is within the normal range, the fetus is too sensitive to the slightest fluctuations in the radioactive background.
Contraindication applies to women at any stage of pregnancy. If you ignore this medical recommendation, then the risks of developing physical abnormalities in the unborn baby increase several times. For the rest, obtaining a layered image of the bloodstream is considered safe.
Due to the fact that the blood flow to the head is closely related to the cervical region, doctors suggest immediately examining the two presented parts of the body. Such an integrated approach gives refined results, which qualitatively affects the development of subsequent treatment. It often happens that the cause of cerebrovascular insufficiency is not the vessels of the head, which cope with the tasks assigned to them perfectly. The problem lies in the pinching of the arteries or veins located in the neck. This situation is quite common, especially among people leading a sedentary lifestyle.
The most important advantage of this non-invasive method for diagnosing the state of blood vessels is the ability to conduct a study several times if it was not possible to obtain the desired clarity the first time. Failures of this kind usually occur due to the involuntary movement of the patient, who is directly in the apparatus.
The technique during the manipulation correctly reveals to the doctor the following aspects of the health of the victim:
- anatomical location of blood vessels in the head, neck;
- the structure of the vascular network;
- the presence of atherosclerotic plaques;
- the size of the veins themselves, arteries and their gaps;
- the presence of vascular constriction and the source of the problem;
- the presence of collaterals.
Since the three-dimensional projection covers a rather large body area under study, an experienced doctor will be able to consider not only the focus of the disease, but also possible concomitant changes and complications.
Usually, a cardiologist or vascular surgeon sends the patient to the diagnostic room. But it happens that doctors of related specialties prescribe angiography to eliminate the risks of an extensive lesion. Among these doctors, a phlebologist and a vertebrologist are distinguished.
The underlying reasons for conducting such a comprehensive check are the following diseases or suspicions of them:
- vasculitis;
- changes in the carotid artery;
- kinking syndrome;
- swelling of the neck;
- painful syndrome in the region of the cervical vertebrae;
- embolism;
- thrombosis;
- angiopathy, as an independent diagnosis, or as a consequence of the development of diabetes;
- benign or malignant tumors;
- control picture after local surgery;
- squeezing of vessels by tumors of various etiologies or scar tissue.
All of the above can be determined by additional examinations and tests, such as classic ultrasound, blood biochemistry. Also, before sending for layer-by-layer scanning, the attending physician must listen to the patient’s complaints and study the history from the medical record.
Having collected all the information together, the doctor will issue a verdict on the lack of nutrition of the brain and problems with its blood supply, which is caused by inadequate vascular activity. CT angiography will help to find the source of the problem.
Who is contraindicated for testing?
If we put aside the most important prohibition for testing – pregnancy, then all other contraindications can be classified as relative. In practice, this means that the decision to ignore them is made by the doctor individually, based on the preponderance of benefit from possible harm.
These relative contraindications include:
- renal failure;
- heart failure;
- diabetes;
- problems in the endocrine system;
- an allergic reaction to pure iodine or seafood in particular.
All of the above applies only to situations where, in addition to the traditional part of the examination, the patient was assigned the stage of contrasting. But since for a thorough study of the state of the vascular bed, it is almost never complete without it, then contraindications are relevant for almost all patients.
The main danger in the study with contrast is the iodine-containing components of the solution for the procedure. If the patient is allergic to them, then they try to replace the drug with rarer analogues.
If the patient is not aware of whether he has an allergic reaction to iodine, then at the stage of preparation for the study, he should be given an allergological test.
Separately, situations are considered when the patient is breastfeeding at the time of the diagnosis. To avoid negative consequences for the child, doctors insist on refusing to feed at least 36 hours after the diagnosis. During this time, most of the harmful components of the contrast solution will be excreted by the kidneys naturally – with urine. To speed up this process, you need to drink more fluids. In this case, it is necessary to express milk and pour it out.
Also, the appointment of CT to small children, the elderly, patients with uncontrolled movements will be questionable. The latter include a group of people with mental disabilities and nervous disorders. The most important condition for obtaining clear visualization is to remain completely still throughout the procedure. Otherwise, the picture will have to be redone again.
Another relative contraindication is the short time interval between CT and x-ray examination. Doctors recommend observing an interval of about four weeks between repeated studies.
Preparation and technology
Angiography does not require any significant preparation. The most important thing is to refrain from eating approximately four hours before the scheduled time for the examination.
Care should also be taken to choose comfortable clothing for the examination that does not contain any metal components. Any jewelry, as well as gadgets, should be left in the dressing room so that their impact does not spoil the visualization. For a while, even dentures and a hearing aid will have to be removed, if they have a place to be.
The procedure lasts about half an hour if the appointment provides for the introduction of contrast. After the solution is administered by intravenous injection or dropper, the patient will be asked to lie down on a medical couch. Since he will have to lie motionless, for the convenience of maintaining a posture, a roller will be placed under his head. And to fix the position, auxiliary straps are used.
After activating the equipment, the couch is sent under the arch of the scanner, which will rotate, taking pictures. Unlike an MRI, which takes quite a long time, a CT angiogram takes much less time, which appeals to claustrophobic people.
During the operation of the detectors, they can emit sound signals, which do not need to be frightened, so as not to accidentally flinch.
Only a diagnostician can name the exact time of the examination, since it depends on the specific model of equipment. The newer versions work a little longer, since their layer-by-layer scanning step is only 0,5 mm. For increased clarity, you have to pay for a longer examination time.
Typically, the results of the diagnosis are handed over to the patient within the next hour, or the next day they are sent directly to the attending physician. The conclusion is not only a snapshot on film and on electronic media, but also an accompanying transcript with a conclusion that reveals the state of health of the vessels of the patient’s area under study.
There are no contraindications after the procedure is completed. Doctors simply advise drinking plenty of water to speed up the excretion of the iodine-containing contrast agent.
Angiography results
The wide diagnostic capabilities of the new generation equipment, taking into account the minimum radiation exposure, make the technique absolutely justified. The data obtained are carefully studied by the patient’s attending physician in order to deal with the identified pathological changes.
In this case, the final diagnosis is made by an experienced doctor after studying the full history, other test results and patient complaints.