Magnetic resonance imaging (MRI) is one of the most informative methods for diagnosing diseases. He gains special diagnostic value in neurological practice. After all, it is with the help of MRI of the vessels of the brain and neck that diagnosis of pathologies of the central nervous system (CNS) is possible in the early stages. Read more about this survey method in the article.
The essence of the procedure
Using MRI angiography of the vessels of the brain and neck, you can see the structure of the arteries of the central nervous system, their shape, location features and more.
This is possible due to the existence of the principle of magnetic nuclear resonance. Its essence lies in the fact that the magnetic field inside the tomograph causes the vibration of hydrogen ions. The energy that is generated in this case is captured by sensors, which leads to the formation of a clear image on a computer monitor.
An even more informative method is MRI of the vessels of the brain and neck with contrast. It involves the intravenous administration of a contrast agent based on gadolinium. Due to this, the vessels are visible even better.
What diseases are diagnosed with MRI?
What does MRI of the vessels of the head and neck show ? Using this research method, it is possible to establish the exact localization of circulatory disorders in the brain and cervical spine.
If you do an MRI without introducing contrast, which is a more economical method, you can determine the following pathologies:
- arterial aneurysm - a bag-shaped protrusion of a thinned vessel wall;
- vasculitis - inflammatory processes in the vascular wall;
- the place of clogging of the vessel with a thrombus or embolus, which leads to a violation of the blood circulation of the distal obstruction (ischemia);
- cysts of the brain and spinal cord;
- neoplasms of the brain and spinal cord;
- impaired blood flow in the carotid artery - the main artery supplying the head and brain, in particular.
Carrying out MRI of the vessels of the head and neck with contrast can increase the diagnostic value of the method. With the help of this examination, it becomes possible to accurately determine the location and size of the tumor, the intensity of its blood supply. And this, in turn, makes it possible to judge its malignancy. Malignant tumors are more intensively supplied with blood.
Also, the introduction of contrast makes it possible to establish the degree of deceleration or acceleration of blood flow in the vessels. It is a contrasting MRI scan done before surgery. This is necessary to evaluate the effectiveness of the operation.
Indications for the procedure
MRI angiography of the vessels of the head and neck is done according to strict indications. These include:
- suspected cerebral atherosclerosis - the accumulation of fat on the inner walls of the cerebral vessels;
- suspicion of the development of a stroke - an acute violation of the blood flow in the vessels of the brain;
- suspicion of the presence of vascular malformations - congenital disorders of the structure of blood vessels;
- stenosis of the cervical vessels accidentally detected by ultrasound (ultrasound);
- discirculatory encephalopathy - a chronic violation of cerebral circulation;
- as a control of the effectiveness of operations on cerebral vessels or arteries of the neck;
- suspected presence of neoplasms of the neck or brain.
Contraindications
Contraindications to MRI are divided into absolute and relative. In the presence of absolute contraindications, this procedure is strictly prohibited. In the second case, making an MRI of the vessels of the head and neck remains acceptable if the intended benefit exceeds the possible negative consequences.
An absolute contraindication is the presence of any metal objects on the human body or inside the body:
- pacemaker;
- joint prostheses;
- insulin pump;
- metal clips on vessels;
- dentures and more.
The presence of metal not only spoils the image quality, but can also lead to damage to the tomograph.
Relative contraindications include the following conditions:
- pregnancy and lactation;
- age up to 7 years;
- mental illness;
- claustrophobia;
- severe renal impairment;
- severe condition of the patient, in which there are difficulties with transporting him to the office of MRI diagnostics.
- hyperkinetic disorders are groups of neurological diseases that are manifested by involuntary movements of the limbs or trunk.
Preparation for the procedure
MRI without contrast does not require specific preparation. But if you decide to do an MRI of the vessels of the brain and neck with contrast, it is worth adhering to several rules:
- Do not eat 8 to 10 hours before the start of the examination, since nausea or vomiting may occur during the administration of contrast.
- If there is an allergy to contrast, you should warn your doctor about this.
- You also need to warn the doctor about kidney disease, if any. Severe impaired renal function impairs the release of contrast from the body.
Immediately before the examination, an allergic test is performed. For this, a small amount of contrast is injected subcutaneously. After this, the nurse monitors the skin reaction. The presence of redness, itching, burning or rash indicates an increased sensitivity of the body to contrast. In such cases, it will have to be abandoned.
Procedure
The tomograph consists of a large rounded apparatus and a table. The patient is placed on the table of the tomograph in a supine position. Hands and feet are attached, and the head is fixed. This is a necessary measure to ensure patient immobility.
The table slides into the tomograph, and he begins to read the image. During operation, the device gives an unpleasant rattle or tapping, so the patient is often given ear plugs.
The doctor is constantly in the next room, which is separated by a glass partition. During the entire procedure, he maintains contact with the patient. Therefore, do not worry.
If there is a need for contrast, it is introduced even before the table is pushed into the tomograph.
On average, a classic tomogram lasts up to 40 minutes, and with the introduction of a contrast agent - up to one and a half hours.
Interpretation of Results
After examining the images by the diagnostician, he makes a detailed description of everything seen in the picture. The doctor characterizes the structure and shape of the arteries, gives a characteristic of the blood flow, the ratio of blood vessels to surrounding tissues. Structures of the brain or neck are also described.
Next, a preliminary diagnosis is made. But the final clinical diagnosis is made by the attending physician. An integrated approach is used for this. The doctor evaluates not only the conclusion of an MRI of the vessels of the brain and neck, but also the clinical data, the results of additional examination methods.
After that, the specialist gives recommendations to the patient and prescribes the appropriate treatment.
Treatment of identified diseases
The treatment of brain and neck vascular diseases detected on MRI directly depends on their type. All therapy can be divided into two groups: drug and surgical.
Drug treatment is aimed at improving blood flow in the cerebral vessels and preventing cerebral edema. So, in acute and chronic disorders of cerebral circulation, the following groups of drugs are prescribed:
- diuretics - "Furosemide", "Torsid";
- decongestants - "L-lysine escinate";
- anticoagulants and antiplatelet agents - "Aspirin", "Heparin", "Warfarin" - to prevent the formation of blood clots;
- Nootropics - "Cerebrolysin", "Piracetam" - to improve metabolism in brain cells.
Inflammatory diseases of the walls of blood vessels (vasculitis) are most often autoimmune. Therefore, treatment is aimed at suppressing the immune response. For this, corticosteroids Prednisolone, Methylprednisolone, the cytostatics Azathioprine, and Cyclophosphamide are used.
With congenital disorders of the structure of the vascular wall (malformation), treatment is aimed at the surgical elimination of the problem. In this case, the operation can be performed both by a neurosurgeon (with malformation of cerebral vessels ) and by a vascular surgeon (with anomalies in the structure of the vessels of the neck).
MRI or ultrasound?
Ultrasound Dopplerography (Doppler ultrasound) is a method of examining blood vessels using ultrasound waves. Using this method, one can also see blood flow in the vessels of the head and neck. What is better - MRI or ultrasound of the vessels of the head and neck?
Although MRI is considered the most informative way of making a diagnosis, it has a number of limitations that ultrasound does not have:
- the need for a long time is stationary;
- the patient should not have any metal objects in the body;
- the development of an allergic reaction to a contrast medium is possible;
- the results are not immediately visible, but after a few hours, and an ultrasound picture can be observed on the monitor in real time;
- high cost of the procedure (3-4 times more expensive than ultrasound).
MRI and ultrasound of the vessels of the head and neck in most cases complement each other. MRI is often done to confirm the results of an ultrasound scan.
We can conclude that MRI is the method of choice for violations of blood flow in the vessels of the head and neck. But if there are contraindications to this method or there are monetary restrictions, ultrasound can also be informative.