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 sophisticated from year to year. Angiography is one of such 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 cerebral vessels, which consists in staining the vascular bed with 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 medium 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 application, cerebral angiography of blood vessels has changed significantly during this time, becoming more perfect.
The essence of the method
In order for the radiologist to see the vessels of the brain, an iodine-based radiopaque substance is injected into one of the cerebral arteries (Triiodtrust, Ultravist). Injection is possible both in the cerebral vessel and through a catheter through an artery at the periphery, for example, the femoral one. Without this procedure, cerebral angiography of the cerebral vessels will be ineffective, as the arteries will be poorly visible in the picture.
Next, two x-rays are taken, in direct and lateral projection. After which the radiologist writes his conclusion.
Types of Cerebral Angiography
There are several classification of this type of examination. It is divided depending on the method of administration of the drug, as well as on the number of vessels that are included in the examination.
The following types of examination are distinguished, depending on the method of injection of an x-ray substance:
- puncture or direct - contrast is injected directly into the cerebral vessel using a puncture;
- catheterization or indirect - contrast is introduced 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 vascular network of the brain is visible;
- selective cerebral angiography of the brain - one of the pools lends itself to examination (in total there are two blood supply pools in the brain: vertebrobasilar and carotid);
- superselective angiography - individual vessels of small caliber are visualized in one of the pools. It is used not only as a diagnostic method, but also as a treatment in which it is removed immediately after visualization of the location of the thrombus or embolus in the vessel.
Indications
For cerebral angiography, a doctor’s referral is required. This diagnostic method is not carried out only at the request of the patient.
The main indications are:
- suspected presence of aneurysm of the brain (saccular protrusion of the artery wall);
- determination of the degree of narrowing of the lumen of the vessel with atherosclerotic plaques (narrowing of more than 75% significantly aggravates blood circulation in the brain, is an indication for surgical intervention);
- location control of clips pre-installed on vessels;
- diagnosis of arteriovenous malformation (pathological 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 location of the tumor;
- visualization of the arteries of the brain during volumetric processes in it (tumors, cysts) in order to establish the placement of blood vessels relative to each other;
- suspected presence of angioma of the brain (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 components of the contrast, you must completely abandon this examination method.
- Renal and hepatic insufficiency in the stage of decompensation. These conditions lead to a violation of the removal of contrast from the body.
- Severe chronic diseases.
- Acute inflammatory diseases, since it is possible to exacerbate the symptoms of infection.
- The age is up to two years, since radiation disrupts the growth and development of the child.
- The period of pregnancy and lactation, since x-ray radiation adversely affects the fetus.
- Mental illness during exacerbation.
- Clotting disorder (hemophilia, thrombocytopenic purpura), which increases the possibility of bleeding after administration of contrast.
Examination preparation
Since the examination method refers to radiological with the introduction of a contrast medium, you need to carefully prepare for cerebral angiography. Preparation includes the following steps:
- A maximum of 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).
- Make electrocardiography and phonocardiography (to exclude heart disease).
- Do not drink alcohol for at least two weeks before the examination.
- Do not take drugs that affect blood coagulation, at least a week before angiography.
- 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 do not appear on the skin, then the test is negative, angiography is possible.
- Do not eat anything 8 hours before the examination and do not drink anything during the last 4 hours.
- It is possible to take tranquilizers or herbal sedatives with significant anxiety. However, it should be remembered that taking these drugs is possible only as directed by a doctor!
- If there is a need - shave the place of introduction of contrast.
- Remove all jewelry and other metal objects prior to 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 the catheter is inserted into the peripheral vein, which is necessary for the instant administration of drugs, the patient is sedated. He is given painkillers, a tranquilizer to achieve maximum patient comfort and relieve pain. The patient is connected to special devices to monitor his vital functions (oxygen concentration in the blood, pressure, heart rate).
Further, the skin is treated with an antiseptic to prevent infection, and contrast is introduced into the carotid or vertebral arteries with direct angiography, and into the femoral - with indirect angiography. If indirect angiography is performed, a catheter is also inserted into the femoral artery, which is pushed through the vessels into the necessary artery of the brain. This procedure is completely painless, since the inner vascular wall has no receptors. The movement of the catheter is controlled by fluoroscopy. Most often, indirect angiography is performed.
When the catheter has approached the desired location, a contrast of 9-10 ml is injected into it, preheating it to body temperature. Sometimes a few minutes after introducing the contrast of the patient, the sensation of heat, the appearance of an unpleasant taste of metal in the mouth are disturbed. But these sensations pass quickly.
After the contrast is introduced, two x-rays of the brain are taken - in lateral and direct projections. Pictures are evaluated by a radiologist. If still unclear, you can re-introduce the contrast and take another two shots.
At the end, the catheter is removed, a sterile dressing is applied to the site of its introduction, and the patient is monitored for a day.
Possible complications
Adverse reactions and complications during cerebral angiography of cerebral vessels do not occur often, up to 3% of cases. However, such reactions may occur, and it is necessary to inform the patient about them. Among the main possible complications, the following conditions are distinguished:
- allergic reactions: from lungs - redness of the skin, itching, rashes, to severe - Quincke's edema and anaphylactic shock;
- the development of a stroke of the brain due to spasm of the arteries;
- an attack of seizures;
- bleeding at the puncture site;
- getting contrast in the soft tissues surrounding the vessel, which can lead to inflammation;
- nausea and vomiting.
Features of CT angiography
Since the method of angiography 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 method of conducting the survey is similar to the traditional one, there are some peculiarities:
- It is carried out not with the help of an x-ray apparatus, but with the help of a tomograph. It is also based on the passage of x-rays through the human body, it immediately takes a large number of images in layers, which makes it possible to more accurately visualize blood vessels and surrounding tissues.
- The image is three-dimensional, which allows you to view the vessel from all sides.
- Contrast injection is performed into a vein, not an artery.
- There is no need to leave the patient under observation after the procedure.
CT angiography is a more effective and safer method of vascular 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 carried out using a magnetic resonance imager and is not an X-ray method, unlike other methods of angiography. This avoids exposure to radiation.
Another advantage of it is good visualization even without using contrast, which is why MR angiography without contrast can be used for allergy sufferers.
The main contraindication to use is the presence in the body of any metal objects (artificial pacemakers, prostheses, implants, metal clips on the vessels).
Perhaps selective cerebral angiography of the brain has already become routine and routine for doctors. Perhaps it is inferior in the effectiveness of CT and MRI angiography. However, being more affordable and not requiring special high-tech equipment, it is also actively used after 100 years to diagnose brain diseases.