MRI of brain vessels. Features of MRI of cerebral vessels. When to get tested

Magnetic resonance imaging (MRI)- a highly informative examination that visually shows the structure of organs, their relative position and functioning in dynamics. MRI provides valuable information for a doctor when examining cerebral vessels. This type of MRI is called magnetic resonance angiography.

The study of the blood supply to the brain is quite challenging task. Cerebral arteries and veins are located under the bones of the skull, so Doppler scanning of them is not possible. MRI of brain vessels is performed with contrast to highlight them against the surrounding tissue.

Unlike X-ray angiography of cerebral vessels, MRI visualizes not only the shape, tortuosity and diameter of the lumen of cerebral arteries and veins, but shows their functioning: elasticity, resistance and tone vascular walls, filling of blood vessels, consistency of the valves of the veins, outflow of blood from the venous sinuses.

✓ How much does such an examination cost? The cost of one MRI session of the head with contrasting of blood vessels in Moscow ranges from 2 thousand to 20 thousand rubles. It can be done in more than 60 diagnostic clinics.. Here you can also familiarize yourself with real reviews patients, which will help in choosing the most suitable diagnostic center.

What does MRI of cerebral vessels show?

What can be seen in the photographs? A contrast tomogram of the vessels of the head reveals:

areas with obstructed blood flow (thrombosis, ischemia);
stagnation venous blood in the sinuses (with infections, coagulopathies, taking oral hormonal contraceptives);
new anastomoses between vessels (with long-term syndrome stealing as compensation for the lack of blood supply to certain areas of the brain);
loci with excessive blood filling of the medulla (as a result of brain contusions, hematomas, hemorrhages);
new vascular growths (with benign and malignant neoplasms- hemangiomas, angiosarcomas);
vascular deformations (congenital and acquired aneurysms, stenoses);
anomalies and pathologies of the structure of blood vessels and their walls (wall dissection, atherosclerotic plaques);
condition of surrounding tissues.

Taking into account how many abnormalities can be detected using MR angiography, the indications for its implementation are:

atherosclerosis of cerebral vessels;
stroke (ischemic, hemorrhagic);
sinus thrombosis;
suspicion of aneurysms, arteriovenous malformations;
vasculitis;
vertebrobasilar insufficiency, steal syndrome;
vascular tumors;
diabetic angiopathy;
headaches, dizziness;
head and neck injuries, cerebral compression syndrome.

How is MRI of cerebral vessels done?

The MR angiography procedure is painless and harmless, so it can be performed even on small children.

A magnetic resonance imaging scanner creates a magnetic field that can affect the hydrogen atoms in water molecules. Under the influence of magnetic pulses, hydrogen atoms begin to emit energy, which is captured by ultra-sensitive sensors built into the tomograph.

To highlight the vessels against the background of surrounding tissues, before the procedure, the patient is intravenously injected with a paramagnetic contrast agent based on gadolinium. It's inert for human body a compound that has the property of enhancing the magnetic field, as a result of which the blood contrasts on the tomogram.

Gadolinium drugs do not bind to blood plasma proteins, therefore they are quickly eliminated from the body without causing any adverse reactions after the examination. With normal renal function, the contrast agent is excreted unchanged after 12 hours. results clinical trials show that allergic and anaphylactoid reactions in response to intravenous administration drugs occur extremely rarely.

For MRI of brain vessels, tomographs are used that produce a magnetic field of at least 0.3 Tesla. The higher the power of the magnetic coils of the devices, the more contrast the pictures are obtained. The duration of magnetic resonance contrast examination of cerebral vessels is about 20 minutes (excluding preparation for the procedure).

Since the examination is based on the impact of a powerful magnet on the human body, the subject must remove all metal products and accessories before the examination. The procedure takes place in a room in which a tomograph is installed. Diagnostic equipment equipped with a movable table on which the patient lies for examination. The supine position of the patient during the examination allows it to be carried out on bedridden patients, unconscious patients and under anesthesia.

The patient must lie motionless on the tomograph table during the tomography. Overly agitated patients may be prescribed sedatives. Young children may be with their parents or other accompanying persons during the procedure. This reduces children's anxiety and their fear of research.

During the examination, the tomograph makes many thin sections in different planes, which, superimposed on each other in a special program, create a three-dimensional image on the device’s monitor. Cerebral arteries and veins on an MR angiogram look like a spider's web inside the skull.

Most often, the study of cerebral arteries and veins is done together with tomography of the vessels of the vertebrobasilar zone and neck. This comprehensive examination allows you to objectively assess the blood supply to the brain and detect the cause of its disturbance.

MR angiography has a number of advantages over other methods for diagnosing cerebral vascular pathologies. Unlike X-ray contrast and computed tomography angiography, MRI does not have an ionizing effect on the subject, so there are no restrictions on the frequency of its implementation. This is very important for monitoring the effectiveness of the treatment, in particular anti-tumor treatment.

Contraindications for the procedure

pregnancy;
period breastfeeding;
the presence of metal products in the patient’s body (dentures, plates, pins, bolts, staples);
anxiety and psychopathic conditions;
epilepsy;
heavy somatic pathologies(failure of the heart, kidneys, liver);
allergy to contrast agent (very rare).

It should be noted that pregnancy and breastfeeding are relative contraindications for MR angiography. Evidence of any negative influence magnetic field on a developing fetus or infant no, but still, during these periods of a woman’s life, it is better to refuse to undergo an MRI. This is due to the fact that examination of cerebral vessels is carried out with contrast. The decision to conduct magnetic resonance imaging in pregnant and lactating women should be made in consultation with the obstetrician-gynecologist caring for the woman.

Screening of pregnant or lactating women is carried out in cases where the likely benefit from it will be greater than possible harm. However, if possible, it should be prescribed in the second or third trimester of pregnancy. After the procedure performed on breastfeeding women, doctors recommend stopping breastfeeding for 2-3 days.

Is special training needed?

MR angiography of cerebral vessels does not require any preparation. Considering that the paramagnetic is excreted by the kidneys, it is advisable to carry out biochemical analysis blood for creatinine clearance, which shows the state of glomerular filtration.

On the eve of the procedure, it is forbidden to drink alcohol and drugs that affect vascular tone for several days. If the patient is taking vasoconstrictors or vasodilators, the possibility of canceling them before the examination requires consultation with the attending physician. On the day of the examination, it is better not to eat or drink anything. At extreme thirst Just take a few sips of water.

To determine pathologies of a person’s head, the doctor may refer the patient for MRI diagnostics of the brain or MRI of brain vessels. What is the difference between the two procedures is unclear to most patients.

Despite the fact that the scanning is carried out using an MRI scanner, the sessions are different because they provide non-identical resultant information. To determine the difference between diagnostics, it is worth delving into the details.

Magnetic tomography of cerebral vessels

This type of diagnosis demonstrates exclusively the vascular structure of the organ (arteries, veins) - the brain itself is not visualized.

Vascular MRI

MRI helps to study physiology and anatomy in detail circulatory system, determine the course of biological and physicochemical processes occurring in the brain.

Indications for MRI diagnostics of blood vessels may include:

frequent migraines of unknown origin;
dizziness;
ear noise;
vegetative-vascular dystonia;
ischemia.

The result of the scan is a three-dimensional demonstration of the process of blood supply to individual areas of the brain in a given projection.

The advantage of such MRI is the ability not only to visualize the structure of blood vessels, but also to assess the level of functionality.

Magnetic tomography of the brain

The procedures take about 20 minutes. In some cases, a combination of diagnostics is justified, in which it is possible to conduct a full assessment of the state of health.

Lists of diagnosed pathologies

MRI of the brain is “responsible” for the structure of the anatomical unit and helps diagnose a number of the following diseases:

MRI of cerebral vessels is performed using the same equipment, only in angiography mode.

The method helps to see arterial and venous walls and assess the speed and volume of blood flow over time.

The procedure helps diagnose the following pathologies:

Consequently, an additional difference between the procedures lies in the indications for their implementation. It is also important to note that the two types of MRI diagnostics are not interchangeable.

Contraindications to examinations

The choice of a specific technique is preceded not only by an assessment of the sheet of indications, but also by familiarity with the limitations of scanning.

Among absolute contraindications The first trimester of pregnancy is the time for both types of examinations.

Devices and metal elements implanted into the patient’s body can become an obstacle to scanning:

The list of contraindications in the case of contrast scanning has been expanded. Such diagnostics are not carried out for pregnant women throughout the entire pregnancy. The procedure is also prohibited for people suffering from kidney failure.

Among the relative restrictions on the use of MRI diagnostics:

the patient’s weight is more than 120 kg (it is possible to use specialized equipment);
neurotic disorders(it is possible to use sedatives);
claustrophobia (diagnosis in an open-type tomograph is indicated);
children under 7 years of age (if the examination is necessary, anesthesia is used).

Analyzing scan results

After MRI of brain vessels or magnetic tomography of an organ, the resulting images are interpreted by a radiologist. Then the doctor analyzes the information, draws up a conclusion, which he hands over to the patient.

Even if we take into account the fact that the procedure is maximally informative, after transmitting the research conclusion, the attending physician often requires the results additional diagnostics.

In some cases, images may be of poor quality and require re-examination (sometimes using contrast).

Duplicate scanning may be necessary if it is necessary to monitor the patient’s condition and evaluate the ongoing therapeutic course.

Is it possible to diagnose children?

Regarding restrictions on patient examination childhood different kinds MRIs are no different. Each of the diagnostics can be performed on children if there are the following medical indications:

MRI diagnostics are safe for children's health. When examining small patients, anesthesia may be used. In some cases, the use of sedatives is justified.

Preparing a child for examinations does not differ from a number of identical ones. If a contrast agent is used, the patient should not feed 5-8 hours before the procedure.

Attention should be paid to preparing the child for the upcoming event: explaining what will happen in the doctor’s office, how to behave during the scanning process.

The appointment of an MRI of the brain or organ vessels is preceded by ultrasound diagnostics. If the obtained data is insufficient, they resort to using a magnetic resonance imaging scanner.

Magnetic tomography of the brain and MRI of the vessels of an anatomical unit do not differ for the patient. The essence of the method remains identical. The basic difference is the result of the scan and the indications for the examination.

Diagnosis of the vascular system of the brain is necessary when planning treatment for migraine, the presence of an aneurysm and other pathological phenomena.

This technique assesses the condition of the arteries, veins of the organ, and the nature of blood flow over time.

MRI of the brain does not visualize vascular system anatomical unit, but helps to assess the structure of brain tissue. Such diagnostics are indispensable if tumors, neoplasms, stroke, or head injuries are suspected.

The restrictions on conducting surveys are the same in both cases. The procedures are safe for the health of adults and children, so there are no restrictions on scanning small patients.

Video

Magnetic resonance imaging (MRI) of cerebral vessels is prescribed when a stroke is suspected, its type is determined (ischemic, hemorrhagic), after a skull injury, or during preparation for surgery. This method is considered one of the most informative, as it helps to identify the cause of headaches, sudden loss of consciousness, impaired coordination of movements, loss of vision, mental disorders against the background of vascular diseases.

Its advantages: safety (since there is no radiation), the possibility of research even without the introduction of contrast, no age restrictions. Tomography is performed in vascular mode for damage to the intracranial arteries, cervical, and also venous network. In case of a tumor process, MRI of the brain substance and angiography with contrast are recommended; it helps to determine the degree of tumor growth.

The examination is contraindicated if there are implanted metal products or devices in the body (for example, a pacemaker).

📌 Read in this article

MRI of cerebral vessels - what is it?

MRI of brain vessels is a study of the structure of the walls of arteries, veins and sinuses (collectors between meninges). It can be performed without contrast (native MRI) or with the introduction of a contrast agent. In this case, depending on the purpose, both the intracerebral blood networks and the arterial branches of the neck that supply the brain can be determined.

What is the best way to identify the problem?

MRI of the brain is best performed when diagnosing the condition of the brain tissue itself, and when vascular diseases brain requires vascular tomography. The first diagnostic method is recognized as one of the most informative due to the fact that even the smallest structures are clearly visible:

cranial nerves,
posterior cranial fossa,
brainstem,
pituitary,
hypothalamus.

neuronal damage;
inflammation;
developmental anomalies;
tumors;
injuries;
multiple sclerosis;
Alzheimer's, Pick's, Parkinson's diseases;
during examination before surgery and when assessing its results.

Tomography cerebral vessels helps:

correctly diagnose a stroke (distinguish between ischemic and hemorrhagic);
investigate the risk of rupture due to an aneurysm (protrusion of the artery wall), arteriovenous malformation ( congenital anomaly vessels);
assess the blood supply to the tumor and its spread, ingrowth into the vascular network.

Expert opinion

Alena Ariko

Expert in Cardiology

One of the advantages of MRI is the ability to evaluate the structure of the brain, arterial and venous networks without the introduction of contrast. This is possible, since blood, due to its movement and liquid state, itself serves as a kind of contrast agent and gives a hyperintense (amplified) signal.

If it decreases, this means that there is an obstacle to the movement due to vascular spasm or, embolism, compression from the outside (inflammation or tumor process, accumulation of blood).

MRI of cerebral vessels: what the study shows

Examination of cerebral vessels using MRI reveals the cause of headaches, dizziness, episodes of loss of consciousness, visual impairment, mental disorders (only of vascular origin), as it shows the condition of the arteries, veins and sinuses of the brain. Tomography will detect: compression, inflammation, wall rupture or its danger, level of blockage, hemorrhage, abnormalities in the structure of blood vessels.

Indications for use

MRI of the cerebral vasculature is indicated for suspected:

rupture of a vessel due to skull trauma, aneurysm or arteriovenous malformation;
benign or malignant tumor;
stroke due to intracranial hemorrhage or artery blockage cholesterol plaque, thrombus;
chronic disturbance of cerebral blood flow (dyscirculatory encephalopathy);
high intracranial pressure(needed to determine the cause and further treatment tactics).

MRI of the brain

When to do it

MRI of brain vessels is recommended when the information content of previous examination methods is low, that is, when the doctor was unable to make a diagnosis, or the therapy for the disease did not produce results. A neurologist can refer the patient for a tomography after the first examination.

Diagnostics are also carried out for:

clarification of data from other research methods (radiography of the skull, CT, fundus examination);
assessing the effect of therapy for trauma, brain surgery, acute disorder cerebral circulation;
choosing a treatment method - surgical or medicinal.

MRI images of a stroke

What symptoms should you go for?

MRI is prescribed for the following symptoms:

constant headaches;
episodes of loss of consciousness;
darkening of the eyes;
noise in ears;
impaired coordination of movements;
unsteadiness when walking;
memory impairment
hearing loss (after excluding pathology by an ENT doctor);
blurred vision (after examination by an ophthalmologist);
sharp fluctuations blood pressure;
with nausea and vomiting;
loss of muscle strength and sensitivity in the limbs on one half of the body;
loss of visual fields;
slurred speech;
migraine attacks;
convulsive muscle twitching;
epileptic seizure;
sudden onset of headache, deterioration of consciousness, swelling of the eyelids, fever (signs of cerebral sinus thrombosis).

Is it possible to do MRI of cerebral vessels in children?

MRI has no age restrictions; it can be done on children from birth. The method is not accompanied by radiation and can be performed without the introduction of a contrast agent. Therefore, it is considered one of the most harmless; when examining and treating a child, it can be repeated as necessary.

Contraindications

MRI is not performed if:

implanted metal or ferromagnetic structures - staples, vascular clips, plates;
braces;
metal fragments;
installed electronic devices - hearing or cardiac prosthesis, pacemaker, defibrillator, insulin pump;
tattoo - drawing on the skin with paints and metal;
first 3 months of pregnancy.

Limit the possibility of:

heavy general state patient;
mental disorders;
circulatory and respiratory failure in the stage of decompensation, severe shortness of breath when lying down.

If necessary, MRI is performed in these patients after the administration of medications. If you are afraid of closed spaces and have a body weight of 120 kg or more, it is possible to do tomography only with specially designed devices. Due to allergies to contrast media, contrast angiography is contraindicated and is not recommended in patients with renal failure.

MRI angiography of cerebral vessels

MRI angiography of cerebral vessels is divided into arteriography and venography. This is important because when arterial diseases There is often a need to assess the condition of intracardial vascular networks, located inside the skull and extracranial, that is, cervical.

Venography examines the venous branches and sinuses between the membranes of the brain. If, after a preliminary examination, the doctor has doubts about the diagnosis, then arteriography together with venography or MRI of the brain with angiography may be prescribed.

Arteries of the brain

MRI of the cerebral arteries is necessary if you suspect:

Disease	Description
and stroke	Weakness in the limbs on half the body, impaired speech, consciousness, facial asymmetry, severe headache with nausea and vomiting
	Temporary disturbance of cerebral circulation - all signs of a stroke, but they disappear within 24 hours
	Headache, dizziness, memory loss, tinnitus, loss of performance, depressed mood, irritability, tearfulness, impaired coordination of movements, late stage dementia sets in
	Impaired vision, eye movements, severe headache that does not go away after painkillers with nausea and loss of consciousness
Binswanger's disease	in young people due to damage small arteries insomnia occurs sudden changes blood pressure, memory and gait deteriorate, involuntary discharge of urine and feces occurs
	In children, speech, vision, movements and sensitivity in the arm and/or leg are impaired, epilepsy attacks occur, in adults severe migraine-type headaches appear, movements lose coordination
Cerebral vasculitis	Against the background of infection, rheumatism or poisoning, a severe headache begins, limbs weaken, behavior and speech change, vision and hearing suffer, fainting and convulsions occur.

Vascular changes in the brain on MRI appear as a decrease in blood supply to the tissue or accumulation of blood when the artery wall ruptures. It is possible to detect the cause of the headache (tumor, inflammation, vasospasm, blockage with a blood clot).

How to do an MRI of cerebral vessels

MRI of cerebral vessels is done without special preparation; it can be performed on an emergency basis immediately after the patient is hospitalized. If it is prescribed as planned and with the administration of contrast, then it is recommended not to eat for 2 hours.

Before entering the office, you must remove all metal products and leave any electronic devices behind the door. You cannot even take glasses with you, and there should not be any metal elements on your clothes. Such precautions are due to the fact that when ferromagnetic products enter a magnetic field, they become very hot.

The research device looks like a cylindrical tube about 2 meters long. It is surrounded by a magnet. The patient is comfortably placed on the sliding table, and his head and shoulder girdle are secured with straps to ensure immobility during the tomography period. The table moves progressively inside the cylinder. After this, the doctor leaves the office and maintains communication using the built-in microphone.

Watch the video about how to do an MRI of the brain:

With and without contrast

The need to administer a contrast agent most often arises when a tumor formation is suspected. Features of the distribution of contrast help to preliminary assess its type - benign or malignant, and in the latter case, its prevalence, metastasis. Contrast is also needed when diagnosing vascular malformations and anatomical modifications of blood vessels.

Contrast contrast is contraindicated if:

drug allergies;
intolerance to gadolinium-based medications (a test before injection is required);
acute and chronic failure kidney function;
severe liver diseases;
exacerbation of bronchial asthma;
administration of contrast for diagnostics for 2 days.

The injection of the drug is performed before the scan and in most patients it causes a feeling of heat, a metallic taste in the mouth, and tingling of the skin. These reactions are considered acceptable and not dangerous to the body. If you experience coughing, difficulty breathing, or the urge to vomit, you should immediately notify your doctor.

The duration of the procedure is about half an hour. Typically, the most unpleasant feeling during a tomography is the loud knocking of the machine, so you can use earplugs if you wish. You may experience a headache after the MRI is completed. general weakness or nausea. It is recommended to drink as much pure as possible drinking water For accelerated removal of contrast, with native MRI, a half-hour rest is sufficient.

Is anesthesia necessary?

MRI of cerebral vessels under anesthesia is prescribed only when the patient cannot maintain complete immobility:

Small children;
fear of the procedure;
mental disorders;
strong pain;
diseases of the joints or spine;
involuntary movements or muscle twitching.

MRI under anesthesia

As a rule, drugs are injected into a vein to put you into medicated sleep and relax the body muscles.

Price of the procedure

MRI of cerebral vessels costs about 4,000 rubles on average, while there is no difference between intracranial arteriography and venography.

In practice, complex studies are most often needed:

MRI of the brain with angiography (venography) – 7,500 rubles;
arteriography and venography – 7,000 rubles;
MRI of the brain + tomography of the intracranial and neck arteries – about 9,500 rubles;
full MRI (brain, neck and cerebral arteries, veins) – 12,000 rubles.

Alternative examination methods

MRI is considered the most informative, providing images with high quality, allowed for children and pregnant women. If it cannot be carried out due to metal elements in the body or other contraindications, then it is prescribed CT scan, often with the introduction of contrast.

A cheaper method is radiography of the skull bones, but it allows us to judge brain tissue only indirectly. To identify vascular pathology, a neurologist may recommend Doppler sonography; it is safe, however, it does not always help to make the correct diagnosis.

MRI of cerebral vessels is performed to detect atherosclerotic changes, when a stroke is suspected, or to distinguish ischemic from hemorrhagic. It is needed to determine the cause of persistent headache, loss of consciousness, seizures, memory impairment, and hearing loss. It can be with or without a contrast agent. If it is impossible to remain still, it is done under anesthesia.

MRI of the head in vascular mode

The procedure for examining blood vessels using magnetic resonance imaging is absolutely painless and harmless due to the absence of radiation exposure to the body. Depending on the purpose, MRI of the head vessels can be performed with or without a contrast agent. Vascular tomography provides information about such pathological changes, How:

narrowing or blockage of blood vessels;
vascular aneurysms;
disturbances of blood flow in the brain;
mechanical damage to blood vessels;
pathologies of vascular development.

When performing magnetic resonance imaging of the vessels and veins of the head, it is possible to determine the degree of damage as a result of injury, diagnose blood flow disorders, and detect the presence of neoplasms.

Indications for tomography:

Magnetic resonance imaging of blood vessels is prescribed if there is a suspicion of serious pathologies blood supply to the brain. This method is considered indispensable for early diagnosis cancer. Vascular tomography is indicated for the patient in the following cases:

if you experience constant headaches, dizziness and loss of consciousness;
in the presence of epileptiform and other seizures;
in case of frequent surges in blood pressure;
if vascular thrombosis is suspected;
if you suspect a head tumor;
after a stroke;
after injury or damage to the cervical region.

The examination itself takes 20 to 30 minutes and does not require special preparation unless contrast is used. The results will be ready 20-30 minutes after the test.

Price

The cost of tomography of cerebral vessels in Moscow varies from 3,000 to 8,000 rubles. To get an MRI of the head in vascular mode, it is better to go to highly specialized centers, then you will not have to pay for contrast during the procedure and the cost will be half the price.

MedSeven Medical Center offers MRI of the vessels and veins of the brain at a low price at the very high level. Our diagnostic center has a powerful tomograph with special head coils, which allow tomography in vascular mode without the use of contrast.

Registration for MRI of cerebral vessels:

MRI of cerebral vessels currently one of the most informative and safe methods diagnostics of cerebral vascular diseases, as it allows for three-dimensional reconstruction of both arteries (MRI arteriography) and veins (venography). In addition, MRI allows you to visualize nearby brain tissue, which is especially important when it is necessary to diagnose strokes. Images of nearby tissues have high clarity and, therefore, MRI examination allows diagnosing microstrokes and small tumors. MRI of cerebral vessels allows you to visualize not only morphological changes in the vascular bed, but also to determine the speed of blood flow. Doesn't use MRI ionizing radiation and therefore examinations can be repeated quite often. MRI of brain vessels is possible only on high-field devices (1 or more Tesla), since high resolution is required. MRI of cerebral vessels very informative and can provide sufficient information about the condition of the vessels even without the use of contrast.

Cerebral vascular abnormalities, which are pathologies of the arteries and veins, can lead to life-threatening conditions. As a rule, MRI of cerebral vessels is indicated when it is necessary to exclude an aneurysm, developmental anomalies (vascular malformations), or to search for the source of bleeding.

MRI of brain vessels allows you to evaluate:

Internal carotid arteries
Basilar arteries
Circle of Willis (the arterial system is the basis of the blood supply to the brain)
Venous vessels (venous sinuses)
MRI of cerebral vessels also allows us to partially assess the condition of the brain tissue, pituitary gland, and brain stem.

Given its high resolution, MRI examination of blood vessels is significantly more informative than research methods such as CT, X-ray or ultrasound.

Indications for MRI of cerebral vessels:

Cerebral circulatory disorders
Vertebrobasilar insufficiency
Acute ischemic stroke
Cerebral aneurysms
Vascular malformations
Tinnitus of unknown origin
Intracranial hypertension
Headaches of unknown origin
Arachnoiditis
Anomalies of vascular development
Dissecting aneurysm
Brain injuries (bruise, concussion)
Vegetative-vascular dystonia
Nosebleeds
Atherosclerosis of cerebral vessels

Contraindications for MRI of cerebral vessels:

Clips on vessels
Some types artificial valves hearts
Defibrillators or cardiac pacemakers
Cochlear implants
Kidney disease (if contrast injection is necessary)
Joint endoprostheses
Some types of vascular stents
Dental prostheses with metal.

MRI of brain vessels can be performed without the use of contrast and allows you to visualize not only the vessels, but also nearby tissues. In addition, the advantage of MRI examination is the ability to visualize tissue, but also determine functional characteristics blood flow If necessary, an MRI with contrast can be performed.