Brain vessels MRI is a diagnostic method aimed at studying the structure of brain vessels and the nature of blood flow. The technique makes it possible to visualize arteries, veins and venous sinuses, to assess the features of blood flow and its circulation in brain tissues. In the process of MR angiography, compression, occlusion, inflammation or violation of the integrity of the vascular wall, malformations, arteriovenous fistulas, hemorrhages can be detected.
Brain vessels MRI is prescribed with low information content of other research methods. The main complaints that may require this procedure are regular headaches, frequent loss of consciousness or fainting, coordination disorders, lability of blood pressure, accompanied by nausea and vomiting, sharp deterioration of vision, hearing, speech or memory, epileptiform attacks, migraine. MRI is also performed in the presence of symptoms of cerebral sinus thrombosis – a sharp headache, vomiting, confusion, swelling of the eyelids, exophthalmos, chills.
The list of indications includes head injuries with suspected skull base fracture or intracranial hemorrhage, benign or malignant tumors, ischemic or hemorrhagic stroke, dyscirculatory encephalopathy against the background of infectious pathologies, hypertensive crises or acute intoxication. Scanning is performed for abnormalities of the structure of cerebral vessels, atherosclerosis, arachnoiditis, aneurysms, Alzheimer’s disease, Binswanger, Parkinson’s disease. The technique is used to evaluate the effectiveness of treatment after injuries, strokes or open brain surgery.
The procedure is contraindicated for persons with implanted metal structures, ferromagnetic or electronic devices (steel plates, spokes, pacemakers, defibrillators, internal hearing implants, insulin pumps, vascular clips). The list of contraindications also includes tattoos made with paint with an admixture of metals, mechanical heart valves, the first trimester of pregnancy. Relative contraindications are the patient’s severe general condition, mental illness, claustrophobia, severe heart failure, II-III trimester of pregnancy, the presence of non-ferromagnetic middle ear implants, the patient’s weight is more than 120-150 kg. The introduction of contrast agents is not performed in case of allergic reactions to similar drugs in the anamnesis, renal insufficiency, thyrotoxicosis.
Immediately before the study, it is necessary to remove all metal objects: jewelry, watches, hairpins, dentures, hearing aids, etc. It is not recommended to use cosmetics, since it can contain components that distort the data obtained. Patients who are unable to remain motionless (children, persons with mental illnesses, phobias, severe pain or involuntary movements) are recommended medication sedation, which is performed by an anesthesiologist immediately before the start of the scan.
Methodology of conducting
Brain vessels MRI is performed in a separate, specially equipped office. Outwardly, most of the devices resemble a large pipe (magnet) with a hole and a table in the middle. Sometimes systems with open sides, top or with a “short tunnel” are used. The patient is placed on the table of the device, fixed, a roller is placed under the head. If necessary, an intravenous catheter is installed and an infusion system is connected to introduce contrast. Then the table is moved inside the tunnel, the doctor goes to the next office, from which he watches the patient and communicates with him via a two-way communication system.
The duration of MR angiography of the brain ranges from 30 minutes to an hour and a half. Throughout the study, the patient should lie still. During the scan, there may be a feeling of warmth and tingling in the head area, and discomfort may occur when using contrast. Allergic reactions to gadolinium preparations are extremely rare. This diagnostic manipulation usually does not affect well-being, in some cases, headache, weakness or mild nausea persists for some time.
According to the results of vascular MRI, it is possible to identify structural abnormalities of brain tissues, detect tumors and assess their vascularization, determine vascular stenosis or sclerosis, hemorrhages, hematomas, aneurysms and vascular malformations, violations of the patency of venous sinuses, thrombosis (with precise localization), slowing of blood flow. All changes are described in detail in the conclusion, but the final diagnosis is established only by the attending physician. On average, the preparation of the results takes about 1 hour. The specialist draws up a written or printed conclusion, the resulting images are recorded on a CD and printed out. In some clinics, the result of the study may be sent to the patient by e-mail.