Modern medicine is developing incredibly fast. Now you will not surprise anyone with ultrasound and X-ray studies. But even these surveys are becoming more and more perfect from year to year. Angiography is one of these methods that allows you to see the size, shape, contours of the vessel.
How can you see the vessels of the brain?
Cerebral angiography is an X-ray method for visualizing the vessels of the brain, which consists in staining the vascular bed with a previously introduced contrast. This is a highly effective and modern diagnostic method that allows you to make an accurate diagnosis.
The method of visualization of blood vessels using a contrast agent has been known to medicine for about a century. Back in 1927, a neurologist from Portugal began using this method, and he came to Russia in 1954. Despite such a long use, cerebral angiography of vessels has changed significantly over this time, becoming more perfect.
The essence of the method
In order for the radiologist to see the vessels of the brain, onean injection of an iodine-based radiopaque substance (Triiodtrast, Ultravist) is performed from the cerebral arteries. Injection is possible both into a cerebral vessel and through a catheter through an artery in the periphery, for example, a femoral one. Without this procedure, cerebral angiography of the vessels of the brain will be ineffective, since the arteries will not be visible in the picture.
Next, two x-rays are taken, in frontal and lateral projection. After that, the radiologist writes his opinion.
Types of cerebral angiography
There are several classifications of this type of survey. It is subdivided depending on the method of administration of the drug, as well as the number of vessels that are included in the examination.
The following types of this examination are distinguished depending on the method of injection of the x-ray substance:
- puncture or direct - the contrast is injected directly into the brain vessel using a puncture;
- catheterization or indirect - contrast is injected using a catheter through the femoral artery.
Depending on the vastness of the vessels that can be visualized, the following types of angiography are distinguished:
- general angiography - the entire vasculature of the brain is visible;
- selective cerebral angiography of the brain - one of the pools can be examined (there are two pools of blood supply in the brain: vertebrobasilar and carotid);
- superselective angiography - individual vessels of small caliber are visualized inone of the pools. It is used not only as a diagnostic method, but also as a treatment, in which immediately after visualization of the location of the thrombus or embolus in the vessel, it is removed.
Indications
Cerebral angiography requires a referral from a physician for examination of the brain. This diagnostic method is not carried out only at the request of the patient.
The main indications are:
- suspected brain aneurysm (saccular protrusion of the artery wall);
- determining the degree of narrowing of the lumen of the vessel by atherosclerotic plaques (narrowing of more than 75% significantly aggravates blood circulation in the brain, is an indication for surgical intervention);
- control of the location of the clips pre-installed on the vessels;
- diagnosis of arteriovenous malformation (abnormal connections between arteries and veins; usually congenital);
- suspicion of the presence of tumors, while the angiogram visualizes a change in the normal vascular pattern at the site of the tumor;
- visualization of the arteries of the brain during volumetric processes in it (tumors, cysts) in order to establish the placement of vessels relative to each other;
- suspected brain angioma (a benign tumor formed by the vascular wall);
- lack of information when using other methods of neuroimaging (CT, MRI), but in the presence of patient complaints and symptoms of the disease.
Contraindications
Conducting both indirect and direct cerebral angiography has a number of contraindications:
- Allergy to iodine and iodine-containing substances. In this condition, you can replace the contrast with gadolinium. If there is an allergy to other contrast components, this examination method must be completely abandoned.
- Renal and liver failure in the stage of decompensation. These conditions lead to impaired excretion of contrast from the body.
- Severe chronic diseases.
- Acute inflammatory diseases, as the symptoms of the infection may worsen.
- Under two years of age, as radiation interferes with the growth and development of the child.
- The period of pregnancy and lactation, since X-ray exposure adversely affects the fetus.
- Mental illnesses in the period of exacerbation.
- A bleeding disorder (hemophilia, thrombocytopenic purpura), which increases the chance of bleeding after contrast injection.
Preparation for examination
Since the examination method refers to X-ray with the introduction of a contrast agent, you need to carefully prepare for the cerebral angiography. Preparation includes the following steps:
- Maximum 5 days before the examination, take a general blood and urine test (to determine the condition of the kidneys and exclude the presence of infectious diseases), a coagulogram (to determine the blood coagulation function).
- Makeelectrocardiography and phonocardiography (to rule out heart disease).
- Do not drink alcohol for at least two weeks before the test.
- Do not take drugs that affect blood clotting for at least a week before the angiogram.
- 1-2 days before the examination, perform an allergic test with contrast, which is carried out by administering 0.1 ml of the drug to the patient and further monitoring the reaction on the skin. If redness, rash, itching does not appear on the skin, then the test is negative, angiography is possible.
- Do not eat anything for 8 hours before the examination and do not drink anything for the last 4 hours.
- Tranquilizers or herbal sedatives may be taken for significant anxiety. However, it should be remembered that taking these drugs is possible only as prescribed by a doctor!
- If necessary, shave the injection site.
- Remove all jewelry and other metal objects before angiography.
- Immediately before the examination, the medical staff should explain to the patient the methodology, goals and possible risks of this examination method.
Methodology
Before the examination, the doctor must obtain the written consent of the patient. After placing a catheter into a peripheral vein, necessary for the instantaneous administration of drugs, the patient is premedicated. He is administered painkillers, a tranquilizer to achieve maximum patient comfort and relieve pain. The patient connects tospecial devices to monitor his vital functions (oxygen concentration in the blood, pressure, heart rate).
Next, the skin is treated with an antiseptic to prevent infection, and contrast is injected into the carotid or vertebral artery for direct angiography, and into the femoral artery for indirect angiography. If indirect angiography is performed, a catheter is also inserted into the femoral artery, which is pushed through the vessels into the desired artery in the brain. This procedure is completely painless, since the inner vascular wall has no receptors. The movement of the catheter is monitored using fluoroscopy. The most commonly performed is indirect angiography.
When the catheter has approached the required place, a contrast volume of 9-10 ml is injected into it, preheating it to body temperature. Sometimes a few minutes after the injection of contrast, the patient is disturbed by a feeling of heat, the appearance of an unpleasant taste of metal in the mouth. But these sensations pass quickly.
After the contrast is introduced, two x-rays of the brain are taken - in the lateral and direct projections. The images are evaluated by a radiologist. If there is still uncertainty, it is possible to reintroduce contrast and take two more shots.
At the end, the catheter is removed, a sterile bandage is applied to the insertion site, and the patient is observed for a day.
Possible Complications
Adverse reactions and complications during cerebral angiography of cerebral vesselsoccur infrequently, up to 3% of cases. However, such reactions can occur, and the patient must be informed about them. Among the main possible complications, the following conditions are distinguished:
- allergic reactions: from mild - redness of the skin, itching, rashes, to severe - Quincke's edema and anaphylactic shock;
- development of a cerebral stroke due to arterial spasm;
- convulsions;
- bleeding at the puncture site;
- contrast gets into the soft tissues surrounding the vessel, which can lead to inflammation;
- nausea and vomiting.
Features of CT angiography
Because the angiography method has been used for more than a century, it is constantly being improved. A more modern and high-quality method for visualizing cerebral vessels is cerebral CT angiography. Although in general the survey method is similar to the traditional one, there are some peculiarities:
- It is carried out not with the help of an X-ray machine, but with the help of a tomograph. Also based on the passage of X-rays through the human body, it takes a large number of images at once in layers, which makes it possible to more accurately visualize the vessels and their surrounding tissues.
- The image is three-dimensional, which allows you to view the vessel from all sides.
- Contrast is injected into a vein, not an artery.
- There is no need to keep the patient under observation after the procedure.
CT angiography is more effective and safervascular imaging.
Features of MR angiography
MR angiography is even more informative than CT. It allows you to see soft tissues that are poorly visualized on CT. It is performed using a magnetic resonance tomograph and is not an x-ray method, unlike other angiography methods. This avoids exposure to radiation.
Another advantage is good visualization even without contrast, which makes non-contrast MR angiography suitable for allergy sufferers.
The main contraindication to use is the presence of any metal objects in the body (artificial pacemakers, prostheses, implants, metal clips on vessels).
Perhaps selective cerebral angiography of the brain has already become commonplace and routine for doctors. It may be inferior in efficiency to CT and MRI angiography. However, being more affordable and not requiring special high-tech equipment, even after 100 years it is actively used to diagnose brain diseases.
