Cerebral angiography is a method of examination consisting in an X-ray examination of the cerebral vascular network after the introduction of a contrast agent into the bloodstream. Contrasting makes it possible to study the features of the structure of blood vessels, to identify pathological abnormalities in the blood supply to brain tissues. Angiography is prescribed for suspected aneurysms and arteriovenous malformations, allows you to assess the features of blood circulation in various parts of the brain, to see the places of narrowing and blockages of blood vessels, the presence of bulky formations.
The technique is used to detect vascular pathology of the brain, to detect abnormalities of vascular development, their excessive tortuosity or loopiness, narrowing of the lumen, blockage, asymmetry in the discharge of vascular branches, aneurysms, vascular malformations. Brain angiography allows to determine the degree, prevalence and localization of vascular disorders, to study the state of blood circulation in vascular collaterals (bypass vascular pathways), to assess venous blood outflow.
Timely diagnosis of vascular pathology makes it possible to prevent the development of acute circulatory disorders – ischemia and hemorrhages. In addition, cerebral angiography is used for tumors of the hemispheres and the area of the Turkish saddle. The oncological process in the brain tissue is indicated by the local displacement of arteries and veins, the presence of newly formed (growing into the tumor) vessels.
Brain angiography has the same general contraindications as any contrast radiography. The method is not used for intolerance to iodine preparations, impaired kidney function and thyroid diseases. In addition, it should be remembered about the irritating effect of the contrast agent on the vessels of the brain, the probability of which increases sharply when the concentration of the drug is exceeded.
First of all, an allergic test with a contrast agent is performed, which involves the introduction of 2 ml of the drug into a vein. If nausea, headache, runny nose, rashes or cough occur, angiography is replaced by other methods. The patient should refrain from eating for 8-10 hours before the examination and inform the doctor in advance about taking medications that affect blood clotting. Immediately before the start of the procedure, the patient should remove all metal objects (hairpins, hairpins, jewelry, removable dentures, etc.) from the examination area, put on a special robe.
Methodology of conducting
To introduce contrast, a puncture of the carotid or vertebral artery is usually performed. To study all the vessels of the brain (panangiography), an aortic puncture is performed. An alternative method of introducing a contrast agent is catheterization, in which the peripheral artery (brachial, ulnar, subclavian or femoral) is punctured and a catheter is inserted through it into the mouth of the vertebral or carotid artery, and with head panangiography – into the aortic arch. The catheter is a special plastic tube, its introduction is carried out under local anesthesia, and the passage through the vessel is controlled by X-ray vision.
When contrast is introduced, the patient may experience a rapidly passing sensation of heat or burning, redness of the face, the appearance of a metallic or salty taste in the mouth. After administration of the drug, head shots are taken in anteroposterior and lateral projections. Angiograms are immediately developed and evaluated, if necessary, a contrast agent is additionally injected and a new series of radiographs is performed. This procedure is usually repeated several times. After passing the contrast through the tissues, a final series of images is taken to study the outflow of venous blood. Then the catheter or puncture needle is removed, and the puncture area is pressed down for 10-15 minutes to stop bleeding.
In most cases, the duration of angiography of cerebral vessels does not exceed one hour. After the examination, the patient should be under the supervision of a doctor for 6-8 hours. The specialist periodically examines the puncture site and checks the pulse in the peripheral arteries for timely detection of possible complications. The patient is recommended to drink copious amounts to remove the contrast agent from the body as soon as possible. If the examination was carried out by catheterization of the femoral artery, it is necessary to keep the leg in an unbent state for 6 hours after the procedure.
In modern neurology, angiography of cerebral vessels is considered an almost safe diagnostic technique. In rare cases, there is damage to the vessel during puncture or catheterization. Bleeding may begin at the puncture site, a hematoma, redness or swelling may form, thrombosis is possible. The administration of a contrast agent is sometimes complicated by nausea, vomiting, allergic reactions.