Magnetic resonance imaging (MRI) is one of the most informative methods for examining internal organs in modern medicine. In terms of its diagnostic value, it significantly exceeds the X-ray examination. What is the essence of the technique, and what does MRI angiography of cerebral vessels show? This, as well as many other things you should know about MRI diagnostics, is described later in the article.
The essence of the method
What is it - MRI angiography of cerebral vessels? With its help, you can see in detail the cerebral arteries, their shape, size, relation to the surrounding brain tissue.
All this is possible due to the fact that the scanner emits electromagnetic waves of different frequencies. They lead to the vibration of hydrogen atoms, which are found in large numbers in all tissues of the body. Various concentrationthese atoms in separate areas of the brain is displayed on the screen. It is thanks to this that the brain tissues are visible, each in its intensity.
MRI angiography of cerebral vessels with contrast is separated separately. Its essence lies in the introduction of a special substance that stains the cerebral arteries. It is more informative than a conventional MRI.
What diseases can be diagnosed by MRI?
With the help of MRI angiography of cerebral vessels, an accurate diagnosis can be made. Moreover, not only the nature of circulatory disorders is determined, but also its exact localization. You can also find out how long ago this adverse event occurred.
The diagnostic value of the method is increased by using a contrast agent. But this method is more expensive than classical magnetic resonance imaging, so sometimes it has to be abandoned.
What does MRI angiography of cerebral vessels show without contrast?
- The volume of the hematoma in the brain, the extent of the hemorrhage.
- Center of ischemia in the brain due to blockage of the vessel by a thrombus or embolus.
- Neoplasms and cysts of the brain.
That is, the use of MRI without the introduction of contrast allows you to see brain tissue and damage to the structure of the brain, if any.
Contrast MRI angiography can accurately diagnose a much wider range of diseases:
- aneurysm of the cerebral vessel - saccularprotrusion of its thinned wall;
- precise localization of a thrombus or embolus in ischemic stroke;
- anomalies in the structure of blood vessels;
- exact localization and volume of tumors, since blood supply is significantly increased at the site of the tumor;
- slowdown or acceleration of blood flow in the vessels.
Indications for MRI
MRI in the mode of angiography of cerebral vessels is carried out only with the direction of a doctor to confirm the presence of such diseases:
- cerebral atherosclerosis - deposition of fatty plaques on the walls of cerebral vessels;
- vasculitis - inflammation of the vascular wall;
- ischemic or hemorrhagic stroke;
- vascular malformations - anomalies in the structure of the vessel;
- stenosis of the carotid or cerebral arteries - a decrease in the diameter of their lumen;
- consequences of traumatic brain injury;
- thrombosis of the venous sinus in the brain.
Also, this method is used if the patient has prolonged headaches, the cause of which could not be determined using other diagnostic methods.
Preparing for the survey
No specific preparation is required before undergoing a routine MRI angiography of the cerebral vessels. And in the case when the doctor prescribes an MRI with contrast, before the examination, you need to follow some rules:
- Food must be avoided for at least 10 hours before the examination, as the contrast agent causes unpleasant symptoms in the form of nausea andvomiting.
- The patient should tell the doctor if they are allergic to contrast.
- If kidney disease is present, this should also be reported to the doctor.
Immediately before the introduction of a contrast agent, an allergic test is performed. To do this, the patient is injected subcutaneously with a small amount of the solution. After that, the doctor observes the reaction of the skin. If rashes, itching, redness or swelling appear, it is necessary to refuse to perform contrast or replace the substance.
Before any magnetic resonance imaging, regardless of the presence of contrast, the patient must remove jewelry, metal products. Also, you cannot take plastic cards, metal-framed glasses, electronics into the office.
How is MRI angiography performed?
After all the preparatory steps are over, the patient lies down on the tomography table. Throughout the examination, he must lie absolutely still, so his arms, legs and head are fixed with straps to the table.
If contrast is applied, the nurse injects it before the patient lies down on the table.
After the table automatically slides into the scanner, and the image is scanned. Often at this time, patients experience a panic attack and claustrophobia. The tomograph is quite dark, and the machine itself emits an unpleasant rattle. Therefore, the doctor should consult each patient before the examination and answer all his questions.
If necessary, introductioncontrast, the patient is placed a catheter in a peripheral vein. The right amount of solution is injected through the catheter. It quickly paints over the vascular network of the brain. This allows you to see changes in blood flow, the shape of blood vessels, areas of increased blood supply. There may be slight discomfort at the time of injection of the contrast medium.
Nearby is another room with a computer system, behind which sit a diagnostician and an operator. Here on the monitors there is a layer-by-layer display of the tissues of the brain and its vessels. As a rule, the entire procedure takes up to 40 minutes.
Magnetic resonance imaging is absolutely painless, only a feeling of discomfort due to prolonged immobility is possible. Sometimes there is warmth in the area being examined and a slight tingling sensation.
Contraindications
Answering the question that this is MRI angiography of the arteries of the brain, it becomes obvious that the essence of the method is to create an electromagnetic field. That is why the main contraindication to MRI is the presence of any metal objects in the body (pacemaker, joint prostheses, insulin pump, dentures, vascular clips). If an MRI is performed at the same time, not only the image quality may deteriorate, but the device may also break down.
Other conditions in which MRI angiography of the cerebral vessels is contraindicated are as follows:
- under 7;
- pregnancy period;
- mental illness;
- neurological diseases thataccompanied by hyperkinesis (involuntary movements of the body);
- claustrophobia - a condition in which a person is afraid to be in a confined space;
- the patient's serious condition, due to which he cannot be transported to the diagnostic room;
- Severe kidney disease is a contraindication for contrast MRI.
Breastfeeding is not a contraindication to the examination. But if the introduction of a contrast is provided, lactation should be canceled for a few days after that, since the solution can pass to the baby along with breast milk.
Dignity of the method
The main advantage of MRI angiography of cerebral vessels is the high accuracy and information content of the examination. Only this method allows you to see the structures covered with bone tissue.
Moreover, vascular MRI is much safer than cerebral angiography using X-rays.
Gadolinium contrast, which is used in magnetic resonance imaging, is completely safe and rarely causes allergic reactions.
MRI angiography makes it possible to make a diagnosis already in the early stages of the disease, when changes in the brain tissue are minimally expressed. This makes it possible to prescribe treatment as soon as possible and increases the chances of a successful rehabilitation.
Disadvantages of the method
Despite its numerous advantages, MRI angiography of cerebral vessels has a number ofCons:
- To obtain an accurate image, a person must lie still for more than half an hour.
- Research is contraindicated in people with any metal objects in the body.
- Although small, there is a possibility of an anaphylactic reaction to the contrast.
Many patients are put off by the bulky design. Therefore, the doctor must explain to the patient that the scanner is absolutely safe.
Doctors consultation
The diagnostician who conducted the examination does not make a final diagnosis. It only describes what it sees in the image. The interpretation of the results, their comparison with the clinic and the data of an objective examination is carried out by a qualified specialist. For help, the patient can turn to doctors of the following speci alties:
- neurologist;
- neurosurgeon;
- phlebologist;
- angiosurgeon.
As you can see from the story that this is an MRI angiography of the vessels of the brain and neck, this study is a really effective method for diagnosing vascular pathology, the advantages of which far outweigh the disadvantages.
