Angiography of cerebral vessels
Since 1986 began a new era in medical diagnostics and connected it with the discovery of x-rays. Since that day, the doctors were able to “see” inside a living organism that allow for effective diagnosis of various pathological conditions.
Over the past century, medical science is progressing, and with it the pigment. Every day there are new diagnostic methods, which are characterized by their accuracy and safety for patients.
Great importance in modern medicine is given to this method of diagnosis as angiography of brain vessels. Because on plain x-ray of the skull can not see any of the arteries or veins of the brain. To this end, and developed angiography, which is the “gold standard” to establish the pathology of the vascular bed.
What is angiography of cerebral vessels?
Based cerebral angiography is the holding x-rays of the head after contrast enhancement of the cerebral blood vessels enginecontroller substances. The method makes it possible to consistently visualize all phases of cerebral circulation (arterial, capillary and venous), see the pathological changes of blood vessels of the brain and their localization, is important in the diagnosis of brain tumors.
Angiography is performed by puncture or catheterization of blood vessels, contrast agent and follow up shots.
The brain is provided with blood from 2 main pools – carotid (carotid artery) and posterior circulation (vertebral artery). Accordingly, the contrast can be either carotid artery, or vertebral. In practice, most often the contrast is introduced into the carotid artery.
As radiopaque substances used iodine-containing drugs — urografin, verografin, gipac, kardiotrast, threadtest, triombrast. All of these substances are water soluble and are introduced parenterally. Major complications of their use are allergic reactions to iodine and nephrotoxicity must be considered in patients with reduced renal function.
What types of angiography of cerebral vessels exist?
Depending on procedures there are several types of angiography of cerebral vessels:
- Depending on the method of introduction of contrast medium:
- needle – a substance is injected directly into the vessel through the puncture needle;
- the Cath Suite – introduction of contrast through a catheter connected to the necessary blood vessels.
- Depending on the place of contrast enhancement of vessels:
- common angiography – contrast is realized viacatheter in the abdominal or thoracic aorta;
- selective – when a substance is injected directly into the cerebral vessels by means of puncture or catheterization;
- superselective – when the contrast is applied through a catheter to the branches of the main cerebral arteries 2-4 order.
- Depending on the method of visualization of blood vessels angiography is:
- classic (complete series of radiographic images after contrast enhancement of the cerebral vessels is one of the above described methods);
- CT angiography (execution of a series of images on the CT scan after contrast enhancement with subsequent 3D modeling of tomographic pictures of the vascular bed);
- Mr angiography, or contrast angiography (the use of
Indications for angiography of cerebral vessels
Angiography is used for diagnosis of vascular pathology of the brain and some other diseases of the brain tissue:
Preparation for angiography
Mandatory before conducting angiography perform the test on sensitivity to iodine. For this 2 ml of contrast medium is injected slowly intravenously, after which for several hours watching the patient's condition. If cough, dyspnea, rash, redness, itching, swelling,
Classic angiography of cerebral vessels
This is the first option angiography of cerebral arteries, which for a long time been used in clinical practice before the introduction of CT and MRI. Today this technique is used less and less due to the presence of more informative and safe methods of angiography.
The study is the following. Under local anesthesia, hold the puncture of the external carotid artery with a special needle, through which injected the necessary dose of contrast medium (10-12 ml). The contrast is pre-heated to body temperature.
Then perform a series of ordinary x-ray images in 2 planes with an interval in 1-2 seconds. This gives the possibility to estimate the arterial, capillary and venous phase of blood flow and to see the type and location of the problem, if present.
Contraindications to this procedure is iodine Allergy, children's age, mental disorders, marked atherosclerosis of cerebral vessels, coma,
CT angiography of cerebral vessels
CT angiography refers to modern research methods vascular bed of the brain. The essence of the procedure consists in the following. A contrast agent is administered intravenously (vein of the elbow of the upper limb). After that she performed computed tomography, which is the layer performing the x-ray images of the brain, whichthen with the help of a computer program rekonstruiruet in volumetric images with well-visualized vessels.
The main advantages of CT angiography are:
- no risk from surgical intervention, as in conventional angiography (puncture of the artery);
- significantly reduced x-ray exposure on the body;
- informativeness is many times greater than classic angiography.
Even more informative method is CT angiography, which uses the latest generation of CT scanners – spiral CT.
Contraindications to CT angiography:
- iodine Allergy;
- end-stage kidney failure;
- decompensated diabetes mellitus;
- pregnancy and lactation;
- severe degree of obesity (patient not fit in the CT scanner, as a rule, such a restriction for most machines is 180-200 kg, but there are special scanners for obese people with a limit of 400 kg);
- pathology of the thyroid gland;
- heavy General condition and a coma.
Preparation for CT angiography does not differ from the procedure described above. The study itself is conducted in ambulatory conditions. The patient is placed on the table computed tomography and using the venous catheter and a special metering device (pump) into the cubital vein injected contrast approximately 100 ml for the entire procedure. Then perform a series of shots.
Video about the capabilities of CT angiography:
Mr-angiography of cerebral vessels
This method of vascular imaging of the brain using magnetic resonance imaging instead of x-ray emission use the magnetic field. Thus, with Mr angiography, there is no x-ray load on the human body, that is certainly the advantage of this technique.
Also Mr angiography can be performed with contrast, or without (depending on goals). This method of angiography is an alternative in patients who are contraindicated for the introduction of contrast.
Contraindications for Mr angiography:
- an implanted artificial pacemaker;
- metal implants in the body (metal plates, artificial joints, electronic ear implant, hemostatic metal clips in the body);
- mental disorders;
- severe degree of obesity;
- severe General condition of the patient;
- pregnancy (no data on the harm or its absence on the fetus of a magnetic field).
A disadvantage of the methodology is the relative duration of its implementation – it is necessary from 20 to 40 minutes of stay of the patient in an MRI apparatus.
Video aboutthe indications and capabilities-enhanced Mr angiography:
Possible complications after cerebral angiography
Extravasation of contrast medium
This administration of contrast iodine-containing substances in the soft tissue around the venous vessel. This could occur if incorrect technique of venipuncture (puncture of the vein wall) or by not maintaining the wall of the vein pressure under which the contrast is injected using a special pump. Typically, the output to 10 ml of contrast does not cause serious complications, but when this number is greater, you may develop inflammation of the adipose tissue and the skin at the site of extravasation until necrosis.
This is the most serious complication of angiography. But lately, in connection with the use of modern and safe rentgencontrastnykh substances the number of such cases has decreased significantly.
As a rule, allergic to iodine occurs suddenly (allergic reaction immediate or anaphylactic type). Sharply itching, redness and swelling at the injection site of the contrast, then shortness of breath, weakness, drop in blood pressurethat leads to the development of anaphylactic shock.
Therefore all premises where is carried out an injection of contrast, must be equipped with medicines for emergency, and this procedure should be performed only under the supervision of a physician.
Acute renal failure
The fact that radiopaque substance excreted primarily by the kidneys. In the event of disruption of the renal apparatus (chronic renal failure) the introduction of a large number of contrast leads to ischemia of the cortical substance of the kidneys and the rapid progression of renal impairment up to acute failure and need for dialysis. Because before angiography with use of contrast is mandatory to assess the functional status of the excretory system.
Despite all its disadvantages, angiography of cerebral vessels remains the “gold standard” diagnosis of pathology of the vasculature.