Angiography of cerebral vessels: what is it, indications and contraindications

Angiography of cerebral vessels is an instrumental method of research, which allows to literally "see" the vessels of the brain. To conduct the study, it is necessary to insert a contrast medium into the corresponding cerebral vessel and the presence of an X-ray apparatus, through which the image of the vessels filled with this contrast will be fixed. Angiography of cerebral vessels is not a routine method of diagnosis, it has its own indications and contraindications, as well as, unfortunately, complications. What is this method of diagnosis, in which cases it is used, how exactly do you spend about other nuances of angiography of cerebral vessels, you can learn from this article.

Angiography in a broad sense is the acquisition of images of any body vessels using X-rays. Angiography of cerebral vessels is just one of the varieties of this extensive method of investigation.

Angiography has been known to medicine for almost 100 years. It was first proposed by the Portuguese neurologist E. Moniz in 1927.In 1936 angiography was used in clinical practice, and in Russia the method began to be used since 1954 thanks to Rostov neurosurgeons VA Nikola and E.S. Temirov. Despite such a long period of use, angiography of cerebral vessels continues to improve and to the present.

What is the angiography of cerebral vessels?

The essence of this research method is as follows. A patient in a certain artery of the brain( or the entire network of the arteries of the brain) is given an X-ray contrast substance, usually on the basis of iodine( Urografine, Triiodrast, Omnipak, Ultravist and others).This is done so that the image of the vessel can be fixed on the X-ray film, since the vessels are poorly visualized in the usual picture. Introduction of X-ray contrast substance is possible by puncturing the corresponding vessel( if technically feasible) or through a catheter guided to the necessary vessel from the periphery( usually from the femoral artery).When the contrast material is in the vascular bed, a series of X-ray images is produced in two projections( direct and lateral).The received pictures are estimated by the doctor-roentgenologist, they make conclusions about the presence or absence of a certain pathology of cerebral vessels.

Species

Depending on the method of administration of the drug, this method of investigation may be:

• puncture( when the contrast is injected by puncturing the corresponding vessel);
• is catheterized( when contrast is delivered through a catheter inserted through the femoral artery and advanced along the vascular bed to the required site).

The vast area of ​​the study angiography of cerebral vessels is:

• general( all brain vessels are visualized);
• selective( one pool, carotid or vertebrobasilar one is considered);
• is superselective( a vessel of smaller caliber in one of the blood pools is being investigated).

Super selective angiography is used not only as a method of research, but also as a method of endovascular treatment, when, after determining the "problem" in a particular vessel, this problem is "eliminated" with the help of microsurgical techniques( eg embolization or thrombosis of arteriovenous malformation).

In connection with the widespread introduction of modern diagnostic methods, such as computed tomography( CT) and magnetic resonance imaging( MRI), CT and angiography have recently become more frequent. These studies are performed in the presence of appropriate tomographs, they are less traumatic and safer than simply angiography. But more on that later.

Indications for

Angiography of cerebral vessels is a specialized diagnostic method, which should be prescribed only by a doctor. It is not performed at the request of the patient. The main indications are:

• suspicion of arterial or arteriovenous aneurysm of cerebral vessels;
• suspicion of arteriovenous malformation;
• determination of the degree of stenosis( constriction) or occlusion( blockage) of cerebral vessels, that is, the establishment of a lumen of the corresponding vessels. In this case, the severity of atherosclerotic changes in the vessels is established and the need for subsequent surgical intervention;
• establishing the relationship of the cerebral vessels to a nearby tumor for planning operational access;
• control of the location of the clips placed on the vessels of the brain.

I would like to note that simply complaints of dizziness, headache, tinnitus and the like are not in themselves an indication for angiography. Patients with this symptomatology should be examined by a neurologist, and the results of the examination, as well as other methods of investigation, determine the need for angiography. This need is set by the doctor!

Contraindications

The main contraindications are:

• allergic reaction( intolerance) to iodine preparations and other radiopaque substances;
• pregnancy( due to ionizing radiation during the procedure).In this case, it is possible to perform MR angiography;
• mental illness, which does not allow you to meet all the conditions of the procedure( for example, a person can not stay still while taking a picture);
• acute infectious and inflammatory diseases( as the risk of complications increases);
• violation of the parameters of the blood coagulation system( both downward and upward);
• general condition of the patient, regarded as severe( it can be heart failure of grade III, terminal stages of renal and hepatic insufficiency, coma and so on).In essence, this subgroup of contraindications is relative.

Preparing for angiography

To obtain accurate results and reduce the risk of complications from the procedure, it is recommended:

• to pass the general and biochemical blood tests, including - to determine the parameters of the coagulation system( the limitation period of the analyzes should not exceed 5 days).Blood group and Rh factor are also determined for possible complications;
• to make ECG and FG( FG if it has not been carried out for the last year);
• within 14 days not to consume alcoholic beverages;
• during the last week not to take drugs that affect blood clotting;
• perform an allergic test with a contrast agent. To do this for 1 to 2 days intravenously, the patient is administered 0.1 ml of the appropriate preparation and the reaction is evaluated( the occurrence of itching, rash, difficulty breathing and the like).In case of reaction, the procedure is contraindicated!
• on the eve of taking antihistamines( antiallergic) drugs and tranquilizers( if necessary and only as prescribed by a doctor!);
• do not eat for 8 hours and do not drink water 4 hours before the test;
• bathe and shave( if necessary) the site of puncture or catheterization of the vessel;
• before the study itself, remove all metal objects( hair clips, jewelry).

Engineering for the

At the outset, the patient signs consent for this type of study. The patient is given an intravenous peripheral catheter to have instant access to the circulatory system. Then, premedication is performed( approximately 20-30 minutes before the procedure): antihistamines, tranquilizers, anesthetics are administered to minimize discomfort during the procedure and the risk of complications.

The patient is placed on the table and connected to the instruments( cardiac monitor, pulse oximeter).After treatment of the skin with a local anesthetic and anesthesia, the corresponding vessel( carotid or vertebral artery) is punctured. Since it is not always possible to get into these arteries, a small incision of the skin and a puncture of the femoral artery are most often followed by immersion of the catheter and carrying it through the vessels to the site of the study. The advancement of the catheter along the arterial bed is not accompanied by pain, since the inner wall of the vessels is devoid of pain receptors. Control of the progression of the catheter is performed by means of an X-ray. When the catheter is brought to the mouth of the necessary vessel, a contrast preparation is pre-heated to the body temperature in the volume of 8-10 ml. The introduction of contrast can be accompanied by the appearance of a metallic taste in the mouth, a feeling of heat, a rush of blood to the face. These feelings go on themselves for a few minutes. After the introduction of contrast, X-rays are taken in the direct and lateral projections almost every second several times( which allows you to see the arteries, capillary phase, and veins).Pictures show and immediately evaluate. If something remains incomprehensible to the doctor, an additional portion of contrast medium is injected, and the pictures are repeated. The catheter is then removed, a pressure-impregnating sterile bandage is applied to the site of the vascular puncture. The patient should be observed by the medical staff for at least 6-10 hours.

Complications of

According to statistical data, complications during this diagnostic method occur in 0.4-3% of cases, that is not so often. Their occurrence can be related both to the procedure itself( eg, the flow of blood from the site of the puncture of the vessel), and using a contrast agent. It should be borne in mind that compliance with all conditions in the preparation and conduct of angiography is the prevention of possible complications. The use of iodine-containing drugs of the latest generation( Omnipac and Ultravist) is characterized by less statistics of complications.

So, the possible complications of angiography of cerebral vessels are:

• vomiting;
• allergic reaction to an iodine-containing drug: itching, swelling and redness at the injection site, followed by the appearance of dyspnea( reflex respiratory distress), a fall in blood pressure, a violation of the heart rhythm. In severe cases, anaphylactic shock may develop, which is life threatening;
• spasm of cerebral vessels and, as a consequence, acute impairment of cerebral circulation( up to stroke);
• convulsive seizures;
• ingestion of contrast agent in soft tissues in the area of ​​the puncture of the vessel( outside the vascular bed).If the amount poured into the tissue of the drug is up to 10 ml, the consequences are minimal, if more - then inflammation of the skin and subcutaneous fat;
• the flow of blood from the site of the puncture of the vessel.

CT and MR angiography: which features?

CT and MR angiography of cerebral vessels are inherently a similar study as angiography. But there are a number of features of these procedures that distinguish them from angiography of cerebral vessels. That's about this and talk.

CT angiography

• it is carried out with the help of a tomograph, rather than an ordinary X-ray machine. The study is also based on X-ray radiation. However, its dose is much less than with conventional angiography of cerebral vessels, which is safer for the patient;
• computer processing of information allows you to obtain a three-dimensional image of the vessels absolutely at any point of the study( this applies to the so-called spiral CT angiography performed on a special spiral tomograph);
• contrast preparation is injected into the ulnar vein vein, rather than into the arterial network( which significantly reduces the risk of complications, as the drug becomes an ordinary intravenous injection through the peripheral catheter).
• for carrying out CT angiography, there is a restriction on the weight of a person. Most tomographs can withstand a body weight of up to 200 kg;The
• procedure is performed on an outpatient basis and does not require monitoring of the patient upon completion.

MR-angiography

MR-angiography is characterized by such features:

• it is carried out with the help of a magnetic resonance tomograph, that is, the method is based on the phenomenon of nuclear magnetic resonance. This means a complete absence of X-rays in the procedure( and therefore MR-angiography is allowed in pregnancy);
• can be performed with or without contrast medium( for better visualization)( for example, with intolerance of iodine preparations in patients).This nuance is an undeniable
  advantage over other types of angiography. If it is necessary to use contrast, the substance is also injected into the ulnar vein vein through the peripheral catheter;
• image of the vessels is obtained by three-dimensional due to computer processing;
• series of images takes a slightly longer time compared with other types of angiography, while the person must always lie in the tube of a tomograph. For people suffering from claustrophobia( fear of enclosed space) this is impracticable;
• procedure is contraindicated in the presence of an artificial pacemaker, metal clips on vessels, artificial joints, electronic implants of the inner ear);
• is performed on an outpatient basis, and the patient is immediately released home.

In general, it can be said that CT and MR angiography are modern, less dangerous and more informative research methods than conventional angiography of cerebral vessels. However, they are not always feasible, therefore, the usual angiography of the cerebral vessels is still an actual method of studying the vascular pathology of the brain.

Thus, angiography of cerebral vessels is a very informative method of diagnosing, mainly, vascular diseases of the brain, including stenosis and occlusions, which are the cause of strokes. The method itself is quite affordable, requiring only the presence of an X-ray apparatus and a contrast medium. With all the conditions for preparation and carrying out the study, the angiography of the cerebral vessels gives an accurate answer to the question posed to it with a minimum of complications. In addition, modern medicine has such innovative methods as CT and MR angiography, more shaking, less harmful and traumatic for the patient. CT and MR angiography allow to obtain a three-dimensional image of the vessels, and therefore, with greater probability, not to miss the existing pathology.

Medical Animation on "Cerebral Angiography":