MRI side effects. Side effects of MRI: is it dangerous to do a tomography

Recently, MRI remains one of the most informative and safe diagnostic methods. The examination is carried out using a tomograph, which is a large magnet.Despite the fact that the tomograph does not have any harmful radiation and effects on the body, the information content and reliability of such an examination is very high. However, like any procedure, it has its own contraindications. Failure to follow safety rules can lead to unpleasant consequences.

The tomograph acts on the human body with electromagnetic radiation, which allows you to display a picture on the screen. Different fabrics transmit these waves differently. This electromagnetic response is highly accurate. With the help, you can identify various diseases: from fractures to malignant tumors.

As a rule, there are no negative consequences of MRI when taking into account contraindications and observing safety precautions. A feature of this examination method is non-invasiveness and painlessness. This greatly reduces the likelihood of unpleasant consequences.

Depending on the part of the body being examined, the MRI procedure has several varieties:

• MRI of the head and neck. In this case, the variety includes an examination of the hemispheres, as well as the vessels of the brain, cervical spine, etc. The examination can also help with lesions of the optic or auditory nerve.
• MRI of the chest. The MRI procedure allows you to identify various pathologies of the chest organs: heart, lungs, as well. Quite often, MRI is performed to determine oncology, damage to the valves of the heart or arteries.
• ... This type of MRI is also called magnetic resonance angiography. It allows you to determine the presence of blood clots, plaques, vascular ruptures, as well as various congenital anomalies.
• ... The MRI procedure allows you to examine not only the spine itself, but also adjacent tissues. This will help identify fractures, disc displacement, tissue infections.
• MRI of bones and joints. The procedure is carried out in case of suspicion of various infectious, inflammatory diseases of bone or articular tissue, when examining the consequences of injuries.
• and . The examination includes all abdominal organs:, etc. You can also examine the reproductive system (uterus, ovaries in women, prostate gland in men).

There is also a full body MRI. However, this is a rather expensive procedure. It is used when it is impossible to make a diagnosis, as well as when searching for a malignant tumor and determining the spread of metastases.

Preparation and procedure

The MRI procedure takes a total of 30 minutes. Special preparation is not required, but before the procedure, the patient must fill out a questionnaire, which indicates all possible allergic reactions, the presence of metal parts or parts in the body (prostheses, shunts, electrostimulators).

When using a contrast medium, it is recommended to refrain from eating before the procedure, as a feeling of nausea may occur. Before the procedure, women are advised to stop using cosmetics, as they may contain metal particles. Directions for eating or drinking are only given when examining the abdominal organs.

Also, if there is excess weight, the patient undergoes a weighing procedure. The tomograph is designed for a specific weight. If it exceeds the permissible limits, an open tomograph is used.

The procedure itself takes place in several stages:

1. First, the patient enters a separate room, changes into the given clothes. It is necessary to remove all jewelry and clothing items that contain metal parts. You also need to leave keys, piercings, dentures, if any, belts, watches, etc.
2. The patient enters the MRI room and lies down on a sliding table that slides into the tunnel tomograph. The basic rule of MRI is that the patient must lie motionless during the entire operation of the tomograph. If small children are examined, the procedure is performed under general anesthesia in the presence of an anesthesiologist.
3. During the procedure, there should be no discomfort. But the tomograph is quite noisy, so prolonged hum often leads to headaches. Headphones may be given to the patient.
4. If unpleasant sensations arise, the patient can press the contact button with the doctor and report his condition. In some cases, patients begin to feel claustrophobic during the examination. Unpleasant sensations in a confined space can occur even if the person did not suffer from claustrophobia before.

After the end of the procedure, the patient can pick up the result within an hour or wait for a doctor's consultation, who will decipher the conclusion. Both a snapshot and a written opinion are handed out.

Complications and dangers of MRI

MRI is a fairly safe procedure. There is not a single scientific fact proving the harmful effects of electromagnetic waves on the human body. Many are afraid of this procedure, not understanding its essence. MRI is not an X-ray examination, so there is no harmful radiation in this case.

During and after the procedure, the following complications may occur:

• A fit of claustrophobia. It is rather an unpleasant effect that appears directly during the examination. In severe cases, the patient is offered a procedure using an open tomograph, but the information content in this case will be reduced. If the claustrophobic attack is not severe, a ventilator may be turned on to relieve the patient's condition to provide fresh air, remove a pillow from under the head, or roll over onto his stomach.
• Tissue damage. If there are metal parts in the body, under the influence of the tomograph, they will begin to attract, tearing the soft tissues. The likelihood of such a complication is very small. As a rule, people are aware of the presence of metal objects in the body and report it. Before the start of the examination, the clinic worker performs an additional test using a metal detector.
• Negative effect on the fetus. Pregnant women can have an MRI scan without using a contrast agent, but the effect of tomography on the fetus in the first trimester has not been clarified, so it is recommended to refrain from testing. But if a woman undergoes an MRI scan in the early stages, until she knows about pregnancy, this is not an indication for a medical abortion.
• Allergic reaction. An allergy can only occur to that which is used during the examination. As a rule, private clinics will test for allergies beforehand.

The procedure has no cumulative effect. It can be performed as often as required by the patient. The risk of complications in this case is small, but MRI is never prescribed for prevention. It is advisable to get a referral from a doctor and clarify the state of the body so that there are no unforeseen complications.

Contraindications to MRI

Despite the safety of magnetic resonance imaging, this procedure has a number of contraindications. In order to identify the presence of certain features of the body, a survey is carried out. It helps determine how safe the procedure will be. It is very important that the patient answers all questions honestly.

If the attending physician prescribes the MRI procedure, he warns of the possible consequences and assesses the condition of the patient's body. Preparations are also announced in advance.

The list of contraindications for MRI includes:

1. The presence of metal objects in the body and a pacemaker. Magnetic waves disrupt the operation of the stimulator and attract any metal objects with great force. This could result in serious injury.
2. The presence of insulin pumps. This medical device for administering insulin may also contain metal parts. His work is disrupted under the influence of a tomograph.
3. Pain syndrome. With severe pain, MRI is not performed, since a person cannot be immobile for a long time. Before starting the procedure, it is necessary to relieve pain or carry out another diagnostic procedure.
4. The presence of mental illness. It is impossible to explain to patients with mental illness that it is necessary to remain motionless. In this case, an MRI scan can only be performed using anesthesia.
5. Tremor. The tremor is accompanied by involuntary movements, which can make the procedure difficult.
6. First trimester of pregnancy. During the period of fetal formation, it is undesirable to carry out any procedures and take medications. If a woman needs an MRI, it is recommended to postpone it to the beginning of the 2nd trimester.
7. Epilepsy. The operation of a tomograph can provoke an epileptic seizure, so this disease is a contraindication to MRI.

Some contraindications have already become obsolete. For example, for a long time it was believed that an MRI scan should not be performed if there are tattoos on the body. However, modern tattoo parlors do not use paint containing metal, so there are no consequences with an MRI scan.

Everything you need to know about contrast agent

There are several types of contrast media. MRI uses a contrast that does not contain iodine, so the likelihood of an allergic reaction is minimal. Most often, intravenous administration of a contrast agent is performed. The need for its use is determined by the attending physician.

In most cases, gadolinium contrast agent is used.

The difference between MRI with contrast and without it lies only in more detailed information, defining the boundaries of tumors.

As a rule, the contrast is completely safe and does not lead to any complications. However, some side effects may occur:

• Allergy. An allergic reaction to gadolinium is rare. It manifests itself in the form of skin rashes, itching, redness of the skin at the injection site.
• Demotion. Gadolinium can slightly lower blood pressure, but this does not lead to serious consequences.
• Retention of fluid in the body. This side effect only occurs if you have kidney disease. Edema forms, the drug is slowly excreted, which can lead to intoxication.

MRI is used to examine large joints, joints of the spine, ligaments, tendons and muscles.

The obtained data are used by doctors not only when assessing the state of health and planning further treatment. Information is indispensable for making a decision on the expediency of surgery and correction of postoperative therapy and rehabilitation.

The non-invasiveness of the procedure makes it possible to diagnose joints in children of different ages. For a growing organism, MRI is a completely safe and painless procedure, because it is based on the influence of a magnetic field from the outside (without surgical penetration into the joint cavity).

Very young patients often have a problem with perseverance. Since the study sometimes lasts up to 1 hour, and all this time it is necessary to maintain complete immobility, the child is immersed in a medication sleep. The dose of sedative (sedative) drugs is selected strictly individually for each patient, which eliminates the risk of side effects.

Indications for MRI of joints

MRI of the joints can be performed as prescribed by the attending physician (orthopedist, traumatologist, surgeon) or on the patient's own initiative.

Indications for MRI as directed by a physician:

• detection / confirmation of tumor processes;
• diagnosis / assessment of the state of fractures;
• arthritis, arthrosis (inflammatory lesions of the joints);
• sports injuries (damage to tendons, muscles, ligaments);
• osteochondrosis and / or intervertebral hernia;
• pathological development of the joint;
• habitual dislocations;
• synovitis (inflammation of the bursa);

Indications for MRI on their own initiative:

Contraindications to MRI

Contraindications to MRI of joints can be absolute and relative.

Absolute contraindications (categorically impossible):

• there are implanted metal objects in the patient's body (implants, clamps, vascular stents, etc.) - there is a risk of internal bleeding and other damage to nearby tissues, since metal structures move under the influence of a magnetic field;
• convulsions, involuntary muscle spasm, hyperkinesis - the inability to control body movements does not allow for a high-quality examination;
• allergy to contrast agent (gadolinium) - if necessary, more often to detect tumor formations, contrast is used in MRI diagnostics. If the patient has any reactions to gadolinium, then it is better for him to carry out MRI without contrast;
• chronic renal failure (with MRI with contrast) - gadolinium excreted by the kidneys increases the load on them and can provoke an exacerbation of the disease;
• pacemakers, insulin pumps and other life-supporting electronic devices - a magnetic field can disrupt the operation of these devices, which will negatively affect the general condition of the patient;
• obesity of the patient (weight more than 150 kg) - prevents the patient from being in the MRI capsule, since the diameter of the tomograph can be much smaller than the size of the patient's body.

Relative contraindications (at the discretion of the doctor)

• pregnancy (mainly in the early stages) - the magnetic field can have an adverse effect on the development of the child in the womb, but in emergency cases, MRI diagnostics is possible;
• lactation (breastfeeding) - with MRI with contrast, the next 2-3 days, the baby cannot be fed with breast milk due to the presence of gadolinium in the secretion of the mammary glands;
• the presence of tattoos, the paint of which includes metal - burning and itching may occur at the place of drawing;
• mental disorders - inappropriate behavioral reactions of the patient during the procedure can significantly complicate the study, and in some cases even make it impossible;
• claustrophobia (fear of a confined space) - can cause panic during the examination.

Preparing for an MRI of the joints

Preparatory measures are to get rid of all metal objects (glasses, hairpins, jewelry, etc.). Women are advised not to use decorative cosmetics on the day of the study, because some of its types may contain metal impurities.

It is advisable to exclude all factors that may interfere with the preservation of immobility - before the procedure, go to the toilet, take the necessary medications, put on clothes that do not irritate the skin, etc.

With MRI of joints with contrast, you should not have breakfast on the day of the procedure (contrast is administered only on an empty stomach).

Methodology

The study is carried out in a supine position, on the movable table of the tomograph. The patient's body and limbs are fixed with special fasteners to avoid involuntary movements. If desired, and children without fail, are given earplugs or headphones in order not to hear the sounds made by the scanner during operation. It can be hum, crackling, various clicks. The contrast agent is injected intravenously just before the procedure.

Then the table is moved to the scanner tunnel, which is equipped with a feedback system with the medical staff. In case of pain, nausea or panic, the patient can immediately contact a specialist - the procedure will be stopped immediately. The appliance is well ventilated and well lit to ensure complete comfort.

The duration of the examination of the joints is usually minutes. Contrast-enhanced MRI - up to 60 minutes.

Side effects

Some patients note that after the procedure there is a slight dizziness, nausea, itching at the puncture site with a needle, urticaria. These symptoms are a consequence of the action of gadolinium, are extremely rare and are quickly eliminated by taking appropriate medications.

There were no other, more serious, side effects after MRI of the joints.

Research results

The conclusion and the MRI images are handed over to the hands immediately after they are deciphered by the radiologist. This usually takes about an hour, in difficult cases - a day.

MRI is a rather informative procedure that allows detecting diseases at the earliest stages of development. MRI of joints makes it possible to confirm or deny a preliminary diagnosis, to identify pathological changes in the joint and surrounding tissues, to adjust the treatment regimen, including surgery, to plan measures in the rehabilitation period.

Alternative diagnostic methods

MRI diagnostics surpasses other research methods in many respects:

• obtaining a complete clinical picture of an organ, both inner and outer shell (as opposed to ultrasound);
• no radiation to the body (as opposed to radiography and computed tomography);
• providing a volumetric (3D) image of an organ;
• the possibility of repeated repetition of the procedure.

It is these features that make MRI diagnostics reliable, safe and the most widespread in the world.

However, CT (computed tomography) is the most informative in the study of dense bone structures. MRI, on the other hand, perfectly visualizes soft tissues. Therefore, specialists often use both of these methods to obtain an accurate result.

Diagnosis by symptoms

Find out your probable illnesses and which doctor you should go to.

Radiation diagnostics: what does MRI, PET, CT, X-ray show

Everything is around the bush, but the specifics are here.

MRI diagnostics is a modern high-precision method for studying soft tissue pathology. The probability of establishing a diagnosis when performing magnetic resonance imaging is 97%, which is higher than that of other methods.

Hard tissues are clearly visualized with layer-by-layer computed tomography (spine, joints). The study is not used in the diagnosis of pathology of hollow organs.

X-ray is indispensable for the primary diagnosis of formations of the lungs, osteoarticular system, kidneys. Allows you to identify the primary focus, after the detection of which the final diagnosis is carried out using CT, MRI, ultrasound, or treatment is carried out.

Ultrasound scanning (ultrasound) is considered an indispensable and safe method of primary screening. It is used to accompany some surgical interventions.

Radiation diagnostics gains ample opportunities when the described methods are combined.

What does an MRI study show or what magnetic resonance is capable of?

Each device for performing an MRI examination is intended for a certain range of examinations and qualitatively shows only those structures for imaging that have been developed.

There is special equipment for magnetic resonance imaging:

1. Spine;
2. Brain;
3. Knee and hip joints;
4. Lungs.

To prevent diagnostic errors, the examination should be performed only on equipment designed for this. Magnetic resonance is capable of more, but ask in detail about this through the feedback form from our radiologists.

What is mri diagnostics or physiology of slicing

In magnetic resonance imaging, the patient is placed in a strong magnetic field in a chamber. The vibrational pulses of water molecules are recorded by sensors, and a three-dimensional image is formed by reconstructing the received radio signals.

The physiology of obtaining an image of an organ based on resonance under the action of a magnetic field is based on the fact that hydrogen atoms emit radio waves when vibrating. They are registered by the receiver. Automated software creates a 3D model of the object.

The patient sits on a narrow table along which a large scanner moves, this position is optimal for tissue examination. If necessary, special receivers are installed around the head and limbs. They help you get a clearer picture.

Before contrast studies (of the brain, spine, knee joints), a dye is injected into a vein of the arm or leg. The contrast agent (gadolinium) allows you to more clearly examine the desired anatomical structures. Such a study is prescribed when it is necessary to study the course of blood vessels or visualize anatomical structures that are not normally visible.

During magnetic resonance imaging, the doctor observes the patient through a window in the wall of the control room. The average duration of the procedure is 1 hour. The test may be delayed if a more thorough diagnosis is required.

Patients with a fear of confined spaces are given a relaxation drug 5 hours before the scan. You just need to inform your doctor in advance that you have claustrophobia. The drug may make you drowsy, but it will make you feel comfortable scanning.

Contraindications to magnetic resonance imaging

Contraindications to MRI:

• Wearing a pacemaker
• Installed braces;
• Pregnancy;
• Overweight.

All metal objects must be removed prior to diagnostics. There are no other contraindications to the study.

Is it possible to carry out magnetic scanning during pregnancy

MRI diagnostics during pregnancy can be carried out only from 3 months of gestation. Scientific experiments have not confirmed the effect of the magnetic field on the fetus, but doctors have concerns about its effect on the embryo, whose cells are actively dividing.

However, you should not "get hung up" on this diagnostic method, if you can avoid using it during pregnancy, it is better to perform the procedure after childbirth.

Should you be afraid of mri

You should not be afraid of MRI, since the study is not accompanied by pain. It does not belong to a number of radiation methods, although the equipment is usually located in X-ray diagnostic rooms.

The only difficulty that the procedure causes for many patients is that it is necessary to lie still for a long time. Any movement can distort the research results.

The equipment makes a lot of noise, so before the examination, you should protect the ears with earplugs.

Modern rooms for magnetic resonance imaging of private medical centers are equipped with TVs, and the patient can watch a movie or listen to music while scanning.

What should you tell your doctor before an MRI scan?

Before magnetic resonance imaging, you should inform your doctor about the following conditions:

• Claustrophobia;
• The presence of pacemakers and pacemakers;
• Ear implants;
• Kidney disease;
• Artificial joints;
• Vascular stents.

Patients who work with metals before the study need to carry out additional diagnostic tests for the determination of metals in the tissues of the eye. Under the influence of a magnetic field, they can move and infect organs.

About side effects of magnetic resonance imaging

Side effects of MRI are rare. With the introduction of contrast, the development of allergic reactions to it is possible. This substance is harmful to patients requiring dialysis. If the patient has kidney problems, be sure to inform the doctor about them before starting the procedure.

Some problems arise for radiology doctors with patients suffering from bronchial asthma. If people often take vasodilator inhalers, it is necessary to choose the time of the study so that the procedure takes no longer than it takes to take the drug. In this case, it is possible to temporarily stop scanning to take medication, otherwise the patient will suffocate. It should be understood that many people experience fear when they are in an MRI room.

If a person has a bowel disease, they are asked not to eat 5 hours before the study. Otherwise, the accumulation of gas in the abdomen will not only complicate the study, but provoke an involuntary urge to defecate or urinate.

Clinical studies on the dangers of mri

American scientists have conducted a number of experimental studies on the impact of magnetic storms on human health. Indeed, life near power lines affects cardiac activity: heart rate is disturbed, irritability occurs, apathy and cancer appear.

When conducting mri, a high-frequency magnetic field is used, which does not provoke pathological conditions (at least, they have not been identified in 10 years of using the method). There have been many studies on animals and humans that have not proven the harmfulness of high-frequency magnetic fields to health.

Description of mri or the subtleties of magnetic diagnostics

The MRI description is formed by the doctor of radiation diagnostics. It reflects the state and size of the anatomical structures that are visualized in the images when performing a specific type of study (spine, brain).

If necessary, the doctor asks the patient for the presence of symptoms of the disease. For example, with magnetic resonance imaging of the spine, a slight protrusion of the intervertebral disc (protrusion) can be observed in the image, but in order to draw a conclusion regarding the causes of the pathology, it is necessary to find out whether a person has compression syndrome, limitation of joint mobility.

"Magnetic" diagnostics of the brain

"Magnetic" diagnostics of the brain requires contrasting of certain spaces or vessels that change in pathological diseases. To decide which method and route of administration of gadolinium to use, the radiologist examines the medical history and interviews the patient.

A qualitative description of tomograms is impossible without the results of other instrumental and laboratory methods. Only after analyzing all the information, studying the state of the spine, brain and other organs on the sections, the specialist can form a qualified conclusion. As a result, it is necessary to bring a detailed extract from an outpatient card or medical history for scanning.

A qualitative description of the spine should include:

• The degree of damage to the intervertebral discs;
• The direction of the protrusions;
• The size of the intervertebral fissures;
• The state of the spinal canal.

In practice, very often there is a discrepancy between the real picture and the MRI data when examining the sacro-lumbar spine. The most reliable results are observed when examining the brain, since it consists of "water" tissues. True, the presence of many air pockets requires doctors to use contrast.

On the example of MRI of the spine and brain, we examined the basic principles of the intricacies of radiation diagnostics. There are insignificant differences when examining other organs.

Briefly about the perspective of PET / CT

The introduction of PET / CT (positron emission tomography in combination with a computer analogue) in clinical practice has led to the discovery of prospects for better diagnostics of oncological formations and cardiac pathology.

The essence of the method lies in the use of short-lived radioactive isotopes, which are quickly removed from the body without harming the internal organs. The substances are used to mark the molecules assimilated by the tissues under study. For example, when examining the myocardium, labeled glucose is used. Domestic literature does not have extensive information on the practical application of PET / CT. On the pages of the site we will use translated foreign sources and practice.

Traditional X-ray as the basis of radiation diagnostics

Radiography after the discovery of X-ray rays by William Roentgen has become an indispensable method for examining the lungs for the detection of tuberculosis, pneumonia, and cancers. Modern medicine uses X-ray examination to diagnose injuries of the osteoarticular system, bowel and kidney diseases.

Fluorography remains the only screening method to detect pulmonary tuberculosis in the early stages.

The site was created so that radiation diagnostics does not cause fear or fear in people. It is one of the most effective and accurate research methods when used correctly, which we will talk about on the resource pages. Stay with us!

Any conclusion of our doctors is not a call to action before consulting a personal doctor!

Is MRI of the brain harmful or not?

More and more people are faced with magnetic resonance imaging of the brain, and quite reasonably ask the question, how harmful is this study? Are there any side effects, and how often can this test be done?

Not harmful

As of 2013, no significant side effects from brain MRI have been found. This procedure does not use ionizing radiation, such as in CT or X-ray, thereby cutting off the known risks of previously used diagnostic tools from MRI.

Skin trauma and burns

Typically, the patient will be asked to remove all metal objects prior to undergoing an MRI of the brain. For example, earrings, watches, buttons, hairpins or bracelets. Failure to do so may result in skin injury or burns.

These side effects are rare and can be avoided by following your doctor's instructions before having an MRI of the brain.

Patients should inform their doctor if they have any implanted metal devices such as pacemakers, etc. In such cases, an MRI scan is not possible.

Nephrogenic systemic fibrosis

Patients with kidney disease who undergo an MRI of the brain are at increased risk of developing nephrogenic systemic fibrosis, health experts warn. Although this happens quite rarely.

Nephrogenic systemic fibrosis can lead to progressive thickening of the skin and decreased flexibility of the limbs. These patients have difficulty walking or may completely lose their ability to walk within a couple of weeks.

Allergic reaction

During an MRI of the brain, patients are usually injected with a contrast agent such as gadolinium. This dye helps the doctor differentiate between different tissues and structures in the brain. In rare cases, an allergic reaction to the contrast agent may occur. Side effects of this allergic reaction include shortness of breath, skin rashes, and increased heart rate. If such a reaction begins during an MRI of the brain, the victim is immediately provided with the necessary medical attention.

Read more about MRI diagnostics of the brain here.

Where to get an MRI scan in Moscow - a directory of addresses and phone numbers of clinics:

MRI in other cities:

Read also

Types of MRI

It's important to know

To understand what an MRI is, you need to take a closer look at what this method is based on.

To obtain the best quality images, it is necessary that the child remains absolutely still during the procedure.

The contrast agent used in an MRI scan is called gadolinium.

About the site

Magnetic resonance imaging

The site helps those who need to undergo MRI diagnostics

The harm and benefits of MRI for human health - the effect on the body and the consequences of radiation

Is MRI harmful, and how does the electromagnetic field generated by the device affect the human body? Can a child or a pregnant woman be subjected to the procedure? What happens if diagnostics are performed with contrast enhancement? All these questions arise in many people who receive a referral for a rather expensive diagnostic MRI procedure. Let's try to answer them in this article.

Is an MRI scan harmful to the body?

The method of studying the human body using MRI has been used in medicine for a short time - about twenty years. Most patients have a vague idea of ​​the principle of operation and device structure.

For this reason, when receiving a referral for examining the spine, knee joint, or, for example, the brain, the patient fears whether the scan will harm his body. In fact, magnetic resonance imaging is absolutely harmless in the vast majority of cases. If the doctor takes into account the individual characteristics of the patient's body and the existing contraindications to the procedure, then MRI will not harm.

The effect of MRI on humans

What effect does the use of MRI radiation have on the human body? The operation of a magnetic resonance imager is based on complex electromagnetic radiation. The mobile table, where the patient is located, is placed in the "tunnel" of the apparatus. The "tunnel" is a cylindrical chamber protected by a plastic sheath from a huge magnet that surrounds it on all sides.

Under the influence of the magnetic field of the apparatus, hydrogen atoms in human tissues are reoriented in the direction corresponding to it. Then, when high-frequency vibrations are turned on, they are excited. The signals from the latter are captured by sensors and transmitted to a computer for decoding and forming an image, which shows the state of the tissue or organ being examined. That is, no fundamental changes in the human body occur during the procedure.

Reorientation and excitation of hydrogen atoms are absolutely imperceptible phenomena, they do not affect either the well-being or the health of the patient in any way. It can be concluded that doing research is not harmful.

Exposure to electromagnetic waves

For example, the danger of the development of pathological changes arises with daily long-term (8-9 hours) exposure to an industrial (even non-medical) source of electromagnetic radiation for 2-3 years in a row, without interruption. It is almost impossible to receive such a dose of radiation undergoing short MRI procedures, so there is no reason to fear for your health.

How often can an MRI of the spine and joints be done?

How often is it acceptable to be scanned with an EMF? You can undergo an MRI examination of the spine and joints (including the knee) an unlimited number of times, provided that the person has no absolute contraindications to the procedure.

There is no X-ray exposure to the patient during scans, so there is no need to take long breaks between MRI scans. The procedure can be performed as many times as you like, even within one day - this does not harm your health. For example, when detecting and treating multiple sclerosis, cancer, or injuries of the spine and joints (including the knee), multiple scans are shown over a short period of time.

Is there a danger in conducting examinations for children and pregnant women?

The list of conditional restrictions on the procedure using MRI includes children under 7 years of age and early pregnancy. The harm or benefit of EMF to the fetus is currently not confirmed. Experts say that no cases have yet been identified where scanning led to the development of intrauterine abnormalities. However, due to the fact that in the first 12 weeks the fetus is especially vulnerable, if possible, the examination is recommended to be postponed until delivery or at a later date.

Is magnetic resonance imaging harmful to a child's health? The electromagnetic radiation itself, in the quantities generated by the tomograph, is not dangerous even for the smallest patients. When examining babies, another problem arises - the child cannot lie motionless in the narrow tube of the tomograph.

To carry out a complete procedure and get a reliable result, scanning has to be performed under general anesthesia. The latter harms the cardiovascular and nervous system of the little patient. For this reason, overuse of MRI is not recommended - it can be harmful.

Consequences of using contrast media

If there is a suspicion of the presence of tumors or the need to diagnose the condition of the vessels, contrast-enhanced MRI is indicated. Can you expect various unpleasant surprises after such a procedure?

Gadolinium-based preparations are often used as contrast agents. On rare occasions, they can cause an allergic reaction in the patient. According to statistics, 0.01% of patients undergoing MRI suffer from hypersensitivity to gadolinium. Despite such insignificant indicators, allergy tests will be made before contrast-enhanced diagnostics. If there is no allergy, then the likelihood of unpleasant consequences due to MRI is close to zero.

In what cases is contrasting harmful? MRI with contrast can provoke a deterioration in the patient's health and relapses of chronic diseases if the subject suffers from renal failure or liver cirrhosis. These conditions are among the contraindications for tomography. While carrying a child, a contrast-enhanced procedure is done only in emergency cases.

Contraindications to MRI

An MRI study, in which the device does not irradiate a person with X-rays, but scans through the combined effects of a magnetic field and high-frequency vibrations, is considered one of the safest methods. However, there are a number of contraindications to the procedure. They are subdivided into absolute and relative.

Among the relative prohibitions is the first trimester of pregnancy. The harm of MRI to the fetus in the early stages of development has not been proven at the moment, but it is recommended to postpone the study "just in case".

1. scanning with contrast is prohibited for patients suffering from hypersensitivity to gadolinium or impaired renal excretory function;
2. diseases in the stage of decompensation;
3. mental disorders that are not amenable to even temporary correction;
4. claustrophobia (the patient can be examined only in an open-type apparatus);
5. sewn electrical devices or implants made of metals and alloys in the human body.

The benefits of magnetic resonance imaging

The advantages of MRI over other diagnostic procedures used in modern medicine include:

• the minimum list of contraindications;
• no restrictions on the frequency of sessions;
• the ability to track the dynamics of changes in the state of the body;
• it is permissible to use in the diagnosis of diseases in children from birth;
• low likelihood of side effects;
• especially effective for visualization of structures of the spinal cord and brain, other nerve tissues.

maybe the procedure is harmless, but in my city it’s definitely not useful. I paid a lot of money, as a result, the diagnostician frankly “rummaged” in my card and simply “adjusted” the transcript to the preliminary diagnosis. If you go for an MRI, then only to a highly qualified specialist.

You do not need to redo the MRI, just take the images on the disk to another doctor. The diagnosis gives an excellent result - I was diagnosed with different pains in the spine and prescribed different treatments. Only after the MRI was it possible to accurately determine the disease, an operation was prescribed.

Attention! All information on the site is provided for informational purposes only and is for informational purposes only. For all issues of diagnosis and treatment of diseases, you must consult a doctor for full-time consultation.

Over the past two decades, modern medical science has advanced far ahead, leaving behind the old methods of hardware diagnostics of all internal organs. The fundamentally new techniques for studying the functional activity of the human body that have appeared include such methods as ultrasound, as well as computed and magnetic tomography. The latter method of examination is of great value in diagnosing diseases of the brain, since with its help it is possible to quickly identify the formation of a pathological process and to carry out the necessary therapeutic measures in a timely manner.

However, when receiving a referral for a resonance study, each patient is tormented by the question of whether an MRI of the brain is harmful. In our article, we want to provide accurate information about the principle of operation of a magnetic tomograph, its effect on human health. Tell about when to do an MRI of the brain, as well as about the features of this diagnostic procedure and the presence of contraindications for its use.

The principle of the MRI method

Diagnostic equipment works on the basis of the influence of the electromagnetic field on the hydrogen atoms contained in the cells of the human body. The tomograph has the shape of a space object and consists of the following elements:

• a pull-out table on which the patient under study is located;
• complex system of scanners emitting electromagnetic waves of various lengths.

Oscillatory (or resonant) movements of tissues make it possible to obtain a reflection of the internal systems of the human body on the monitor of the apparatus. As a result of its processing with the help of computer programs, the scanned structures of the spinal cord and brain, internal and musculoskeletal organs receive a graphic or three-dimensional detailed image. The main applications of the MRI method are:

• identification of early stages of pathological processes;
• clarification and confirmation of the diagnosis;
• intermediate control of the ongoing course of medical therapy.

If necessary, the resulting graphic image of the patient's brain is increased in size, transferred to paper and digital media

This study has many advantages over other diagnostic techniques, in particular:

• complete safety (it is assigned even to children);
• obtaining more accurate final data (using the magnetic resonance procedure, you can notice the slightest disturbances in the structure of the brain and changes in its cortex);
• the duration of the examination does not exceed 1 hour, and immediately after its completion, the patient receives a picture.

Whether there is harm from MRI or not, depends on the patient's compliance with all the instructions of medical specialists.

In what cases do they not think about the dangers of diagnostics?

Unlike the computed tomography procedure, which uses radioactive radiation that negatively affects the patient's body, MRI is absolutely not harmful to the child and pregnant women.

Research is necessary if a person has:

• head trauma;
• acute headaches;
• convulsive syndrome (involuntary muscle contractions);
• short-term loss of consciousness (fainting);
• increased intracranial pressure;
• speech dysfunction;
• loss of vision;
• inflammatory processes in the brain (for example, meningitis);
• thrombosis, atherosclerosis or vascular stenosis;
• concussion of the brain.

This procedure may be needed if there is a suspicion of the formation of a tumor-like formation, determining the consequences of a stroke, and correcting drug therapy.

Features of performing diagnostics

The direction for conducting an MRI of the brain is given by the attending physician, who must take into account some of the nuances. The patient is not allowed to have metal implants, special medical devices and devices:

• Elizarova;
• insulin pumps;
• pacemakers;
• artificial heart valves;
• prosthetic joints;
• titanium plates;
• braces;
• metal dentures.

A patient with obvious signs of claustrophobia (fear of a confined space) is advised to take sedative medications on the eve of the procedure.

Before performing the procedure, the patient must put on the appropriate things, and the medical staff warns him about the possibility of using the "panic button" to stop the examination

Magnetic tomography is contraindicated in the following pathologies:

• insufficient renal function;
• various mental disorders;
• bronchial asthma.

Harmful effect on the patient's health from MRI of the brain

The use of the strong radiation of the electromagnetic field, which is generated during the operation of the powerful turbines of the tomograph, makes many patients think about the refusal of the diagnostic procedure. However, science has proven the safety of MRI for the human body - the radiation when performing this technique does not exceed the portion of radiation that a person receives when using a mobile phone! From these results it follows that the negative influence of electromagnetic waves on the human body does not actually exist.

MRI of the brain can be done several times a year if there are indications for determining an accurate diagnosis, monitoring the severity of the course of the disease and the effectiveness of treatment measures.

Could the use of contrast enhancement in MRI be harmful?

A scan of the brain using a contrast agent, which is injected into a patient intravenously, is used to detect tumor processes and visualize the vascular system. Most often it is prescribed for diagnosing cancer and evaluating treatment methods.

Such a survey may be necessary repeatedly. Many patients very often reported severe pain in the head and a deterioration in general well-being after MRI. However, in fact, the diagnostic procedure itself does not have a negative impact. The appearance of such signs is associated with a side effect of contrast and depends on the patient's individual susceptibility to this drug, which is manifested by dizziness, headache, fever.

The contrast used for MRI of the brain contains halidonium, a substance that penetrates into the tissues of an organ during its examination and improves the image on the screen of the apparatus by acting on electromagnetic waves and hydrogen atoms.

An allergic reaction of the body occurs quite rarely. The introduction of a contrast agent is prohibited for patients with severe pathology of the urinary system. In case of minor violations of the excretory function, it is necessary to consult a specialist urologist before performing contrast tomography.

Comparison of MRI, X-ray and CT for harm to the body

It is hardly possible to compare the procedure of magnetic resonance imaging and conventional radiographs. First of all, the final data of fluoroscopy are inferior to scanning organs in terms of information content. In some cases, computed tomography provides sufficient results, its cost is much lower than electromagnetic diagnostics, but the harm to the patient's health is much higher.

Of course, the effect of ionizing radiation, which is used to obtain an X-ray image, is strictly regulated, and the radiation dose standards are calculated for different age categories and depend on the state of human health. Medical specialists who refer patients for CT or X-rays calculate the radiation dose and determine how many times a diagnostic procedure can be performed so as not to harm the patient.

Under certain circumstances (for example, if the patient has loose ferromagnetic implants or endoprostheses), MRI can be unsafe, and CT will solve this problem.

Conclusion

At the end of all the above information, I would like to emphasize once again that the harmful effect on human health of MRI is significantly exaggerated. Compared to many other diagnostic procedures, the effect of an electromagnetic scanner is small. It is not accompanied by ionizing radiation, magnetic waves do not affect the functional activity of the brain and the body of a pregnant woman.

The doctor will answer the patient all questions about the procedure

This diagnostic procedure is widely used to identify pathological processes in which the results of X-ray and CT are of little information. In many cases, the accuracy of the data of modern methods of magnetic resonance imaging outweighs the risk of developing possible complications. The study can be carried out as many times as it takes to normalize the clinical situation.

Magnetic resonance imaging (MRI) is one of the young methods for diagnosing serious pathologies. Despite the fact of high information content and safety of the examination, many patients still hesitate before undergoing a scan. Is MRI harmful? The relevance of this issue remains to this day.

Is there a risk

MRI is based on the magnetic field that prevails in the tomograph. The organs and tissues of the human body are partially assembled from hydrogen molecules, which react to the effects of magnetic waves. This reaction is recorded by the apparatus in the form of photographs, which are subsequently subjected to medical analysis.

Many people may decide that magnetic tomography, based on the principle of computed tomography, is harmful to human health. However, MRI radiation exposure has nothing to do with CT X-ray exposure and therefore does not adversely affect the body.

Separately, it is worth touching on the issue of the possibility of holding and.

Is it possible to carry out diagnostics for children and pregnant women

Irradiation with MRI diagnostics is zero, but experts try not to prescribe such a procedure to children. The examination is rarely used: to confirm the diagnosis and monitor the effectiveness of the therapeutic course. Why is MRI diagnostics so rarely applicable in the case of children, especially small children? Specific sounds of equipment, confined spaces, unfamiliar surroundings can scare a toddler and disrupt research. In such cases, doctors recommend using anesthesia.

Introducing contrast

The harm with MRI of the brain, spine, pelvic organs and other anatomical structures in the absence of contrast is minimal, however, in the case of pregnant women, MRI is contraindicated in the 1st trimester. At this time, the formation of all organ systems of the unborn child takes place, the degree of influence of the magnetic field on these phenomena has not been fully studied, therefore MRI in the first 14 weeks of pregnancy is prohibited (examination is allowed only if there is a suspicion of serious fetal pathology).

In the 2.3 trimester, it is possible to undergo diagnostics, but without the use of a contrast agent, since it can harm the child's body.

After the 1st trimester of pregnancy, MRI is often done to assess the condition of the fetus. The examination takes place without harm to the expectant mother and child.

MRI with contrast

Contrast agent

The use of a contrast agent is often indicated in the framework of magnetic tomography. The essence of the technique consists in the preliminary introduction of a dye to the patient. This approach helps a detailed study of organs and tissues, is applicable in the diagnosis of blood vessels, tumors, diseases of the spine, etc.

When it comes to contrast-enhanced MRI, the list of contraindications for tomography is expanding. Additional restrictions include:

Is there any harm from MRI with contrast? The substance used in the tomography process is based on gadolinium salts, which are characterized by a low toxicity index, which means they are safe for health.

What can be the consequences of using contrast

When using a contrasting component in the process of MRI diagnostics, the likelihood of an allergic reaction cannot be excluded. If we take statistical data as a basis, it can be argued that such cases account for only 0.01% of the total number of MRI examinations.

To exclude even the minimal likelihood of developing an allergy to a contrast agent, the patient needs to undergo an allergy test. If during the procedure, allergic reactions are not established, the risk of occurrence after magnetic tomography is zero.

Among the alarming symptoms during the allergy test:

• redness, swelling of tissues in the area of ​​injection of the component;
• slight itching;
• lowering blood pressure;
• dizziness;
• lacrimation, discomfort in the organs of vision;
• sneezing;
• cough;
• dyspnea.

Allergy test

The appearance of such symptoms is the reason for the refusal of contrasting in the process of MRI diagnostics.

If a patient belonging to a group of persons with contraindications for diagnostics undergoes an MRI with contrast, a deterioration in the patient's well-being and a slowdown in therapeutic dynamics, the development of anaphylactic shock and other side effects are likely.

How often can an MRI be done?

Since MRI does not talk about the effect of radiation on the patient's body, the examination is carried out as often as required by specific clinical circumstances. Before the study, the patient will have to take a referral from the attending physician. In some medical centers, it is possible to undergo MRI diagnostics without a medical referral.

Magnetic tomography is often prescribed for prophylactic purposes. An examination is carried out after surgery to assess the results of therapy.

Often, experts make a decision to carry out the examination several times. Sometimes an MRI is done twice a day. What should be the minimum time interval between the following diagnostics in a row? With a traditional MRI, there is no need to take a break at all. As for magnetic tomography with the use of internal contrast, in this case, the examination is carried out at an interval of at least 3 days.

The only drawback of the frequent use of the method may be the cost of the survey. Too frequent appointments of magnetic tomography justifiably alert patients.

MRI and CT: comparative characteristics in terms of safety

In computed tomography, X-ray radiation acts as the basis of the study, which is harmful to the patient's health. Accordingly, CT diagnostics should be carried out under the strict supervision of a specialist, taking into account previous examinations.

The most harmful diagnostic method (CT)

When undergoing a CT scan, the human body receives a dose of radiation, which can exceed the annual radiation by several times. In order to reduce the radiation exposure to a minimum, tomographs of a new generation are used in practice today.

As for magnetic resonance imaging, there is no place for X-rays in the arsenal of its instruments, therefore this technique is safer and can be performed without a medical referral.

The adverse effect of MRI diagnostics on the body of the examined person is extremely exaggerated. If we compare this diagnostic method with alternative studies, we can say with confidence that it is the safest for the patient's health. Indeed, during examination, the patient is not exposed to ionizing radiation, and the magnetic field does not harm the brain and other anatomical structures of the human body.

The safest diagnostic method (MRI)

This diagnostic method will help out specialists if the results of computed tomography and radiography are ineffective. The accuracy of MRI diagnostics exceeds the likelihood of complications. The study is carried out for small children (under anesthesia), pregnant women (in the 2nd, 3rd trimester of pregnancy). The number of sessions allowed is unlimited.

However, this method cannot be confidently called the best among analogues (computed tomography, radiography), since when choosing a technique, it is necessary to take into account the degree of information content, accuracy, and practicality of the examination.

Video

Magnetic resonance imaging (MRI) is one of the most modern diagnostic methods that allows you to study almost any body system. The most important characteristic of an MRI machine is the magnetic field strength, which is measured in Tesla (T). The visualization quality directly depends on the field strength - the higher it is, the better the image quality, and, accordingly, the higher the diagnostic value of the MR study.

Depending on the power of the apparatus, there are:

■ low-field tomographs - 0.1 - 0.5 T (Fig. 1);
■ high-field tomographs - 1 - 1.5 T (Fig. 2);
■ ultra-high-field tomographs - 3 T (Fig. 3).

At the moment, all major manufacturers produce MR scanners with a field of 3 T, which differ little in size and weight from standard systems with a field of 1.5 T.

Safety studies of MRI have not shown any negative biological effects of magnetic fields up to 4 T used in clinical practice. However, it should be remembered that the movement of electrically conductive blood creates an electrical potential, and in a magnetic field will create a small voltage through the vessel and cause an elongation of the T wave on the electrocardiogram, therefore, when examining in fields above 2 T, ECG monitoring of patients is desirable. Physical studies have shown that fields over 8 T cause genetic changes, charge separation in liquids, and a change in the permeability of cell membranes.

Unlike the main magnetic field, gradient fields (magnetic fields perpendicular to the main, main, magnetic field) are switched on at certain time intervals in accordance with the selected technique. Rapid switching of gradients can induce electrical currents in the body and lead to stimulation of peripheral nerves, causing involuntary movements or tingling sensations in the extremities, but the effect is not dangerous. Studies have shown that the threshold for stimulation of vital organs (for example, the heart) is significantly higher than for peripheral nerves, and amounts to about 200 T / s. When the threshold value [rate of gradient change] dB / dt = 20 T / s is reached, a warning message appears on the operator's console; however, since the individual threshold may differ from the theoretical value, monitoring of the patient's condition is constantly necessary in strong gradient fields.

Metals, even non-magnetic (titanium, aluminum), are good conductors of electricity and will heat up when exposed to radio frequency [RF] energy. RF fields cause eddy currents in closed circuits and conductors, and can also create significant stress in elongated open conductors (eg, bar, wire). The electromagnetic wavelength in the body is only 1/9 of the wavelength in air, and the resonance phenomenon can occur in relatively short implants, causing heating of their ends.

Metallic objects and external devices are generally mistakenly considered safe if they are non-magnetic and labeled “MR Compatible”. However, it is important to make sure that objects that are scanned inside the working area of ​​the magnet are immune to induction. Patients with implants are only allowed to undergo an MRI scan if the implants are both non-magnetic and small enough to heat up during scanning. If the object is longer than half the RF wavelength, resonance with high heat generation may occur in the patient's body. The limiting dimensions of metal (including non-magnetic) implants are 79 cm for a field of 0.5 T and only 13 cm for a field of 3 T.

The switching of gradient fields creates a strong acoustic noise during an MR study, the value of which is proportional to the amplifier power and field strength and, according to regulatory documents, should not exceed 99 dB (for most clinical systems it is about 30 dB).

based on the article "Possibilities and limitations of high-field magnetic resonance imaging (1.5 and 3 Tesla)" A.O. Kaznacheeva, National Research University of Information Technologies, Mechanics and Optics, St. Petersburg, Russia (journal "Radiation Diagnostics and Therapy" No. 4 (1) 2010)

read also the article "Safety of Magnetic Resonance Imaging - Current State of the Art" by V.E. Sinitsyn, Federal State Institution "Treatment and Rehabilitation Center of Roszdrav" Moscow (journal "Diagnostic and Interventional Radiology" No. 3, 2010) [read]

MRI DURING PREGNANCY - IS IT SAFE?

Currently, MRI is a widespread method of radiation diagnostics, which is not associated with the use of ionizing radiation, as in X-ray examination (including CT), fluorography, etc. MRI is based on the use of radio frequency pulses (RF pulses) in a high-strength magnetic field. The human body is predominantly made up of water, made up of hydrogen and oxygen atoms. At the center of each hydrogen atom is a small particle called a proton. Protons are very sensitive to magnetic fields. Magnetic resonance imaging machines use a strong constant magnetic field. After the object under study is placed in the magnetic field of the tomograph, all of its protons line up in a certain position along the external magnetic field, like a compass needle. An MRI scanner sends a radio frequency pulse to the examined part of the body, causing some of the protons to move from their initial state. After turning off the radio-frequency pulse, the protons return to their previous position, emitting the accumulated energy in the form of a radio-frequency signal, reflecting its position in the body, and carrying information about the microenvironment - the nature of the surrounding tissue. Just as a million pixels form an image on a monitor, so radio signals from millions of protons, after complex mathematical computer processing, form a detailed image on a computer screen.

However, certain precautions must be strictly observed when performing an MRI. Potential hazards to patients and MRI staff can be associated with factors such as:

■ constant magnetic field generated by the magnet of the tomograph;
■ changing magnetic fields of the device (gradient fields);
■ RF radiation;
■ devices and substances included in the package of the tomograph, such as cryogens (liquid helium) and electrical cables.

Due to the “youthfulness” of the technique, the small (worldwide) amount of accumulated safety data, the FDA (Food and Drug Administration, USA) together with the World Health Organization impose a number of restrictions on the use of MRI, due to the possible negative impact strong magnetic field. The use of a magnetic field up to 1.5 T is considered permissible and absolutely safe, unless there are contraindications to MRI (MRI scanners up to 0.5 T are low-field, from 0.5 to 1.0 T are medium-field, from 1.0 - 1.5 T and more - high-field).

Speaking about long-term exposure to constant and alternating magnetic fields, as well as radio frequency radiation, it should be noted that there is no evidence of the existence of any long-term or irreversible effects of MRI on human health. Thus, female doctors and radiographers are allowed to work during pregnancy. Monitoring of their health showed that there were no abnormalities in their health or in their offspring.

Magnetic resonance imaging of women of childbearing age requires information about whether they are pregnant or not. There is no evidence of a harmful effect of magnetic resonance imaging on the health of pregnant women or the fetus, but it is strongly recommended to perform MRI for women in position only for clear (absolute) clinical indications, when the benefits of such an examination clearly outweigh the risk (even if very low).

If there are only relative indications for MRI, then doctors recommend abandoning this study in the first three months (up to 13 weeks of gestation, I trimester) of pregnancy, since this period is considered fundamental for the formation of internal organs and systems of the fetus. During this period, both the pregnant woman and the child himself are very sensitive to the effects of teratogenic factors that can cause a violation of the embryogenesis process. In addition, according to most doctors, the first three months, the images of the fetus are not clear enough due to the small size.

Moreover, during the diagnosis, the tomograph itself creates a background noise and emits a certain percentage of heat, which can also potentially affect the fetus in the early stages of pregnancy. As noted above, MRI uses RF radiation. It can interact with both body tissues and foreign bodies in it (for example, metal implants). The main result of this interaction is heating. The higher the RF frequency, the more heat will be generated, the more ions the tissue contains, the more energy will be converted into heat.

The specific absorbtion rate (SAR) displayed on the display screen of the device helps to assess the thermal effects of RF radiation. It increases with increasing field strength, RF power, decreasing slice thickness, and depending on the type of surface coil and the patient's weight. In magnetic resonance systems, protection is installed that does not allow the SAR to rise above a threshold value, which can lead to tissue heating by more than 1 ° C.

During pregnancy, MRI can be used to diagnose pathology in either a woman or a fetus. In this case, MRI is prescribed according to the data of ultrasound diagnostics when certain pathologies in the development of the unborn child are detected. The high sensitivity of MRI diagnostics makes it possible to clarify the nature of abnormalities and helps to make an informed decision about maintaining or terminating a pregnancy. MRI becomes especially important when it is necessary to study the development of the fetal brain, diagnose malformations of cortical development associated with a violation of the organization and formation of the brain convolutions, the presence of heterotopic areas, etc. Thus, the reasons for MRI can be:

■ various pathologies of development of the unborn child;
■ deviations in the activity of internal organs, both of the woman herself and of the unborn child;
■ the need to confirm the indications for artificial termination of pregnancy;
■ as evidence or, conversely, a refutation of a previously made diagnosis based on analyzes;
■ the lack of the ability to conduct an ultrasound scan due to the obesity of the pregnant woman or the inconvenient position of the fetus in the last stage of pregnancy.

In this way, in the first trimester of pregnancy (up to 13 weeks of gestation), it is possible to conduct MRI according to vital indications from the mother, since organo- and histogenesis has not yet been completed, and in the second and third trimesters of pregnancy (after 13 weeks), the study is safe for the fetus.

On the territory of Russia, no restrictions are imposed on MRI in the first trimester, however, the Commission on Ionizing Radiation Sources at WHO does not recommend any effect on the fetus that may in any way affect its development (despite the fact that research , during which children under 9 years old were observed exposed to MRI in the first trimester of intrauterine development, and no abnormalities in their development were found). It is important to remember that the lack of information about the negative impact of MRI on the fetus does not mean that the harm of this type of study for the unborn child is completely eliminated.

note: pregnant [ !!! ] it is forbidden to conduct MRI with intravenous administration of MR-contrast agents (they penetrate the placental barrier). In addition, these drugs are excreted in small quantities in breast milk, therefore, the instructions for gadolinium drugs indicate that when they are administered, breastfeeding should be discontinued within 24 hours after the administration of the drug, and the milk secreted during this period should be expressed and poured out. ...

Literature: 1. article "Safety of magnetic resonance imaging - current state of the art" V.E. Sinitsyn, Federal State Institution "Medical and Rehabilitation Center of Roszdrav" Moscow; Journal "Diagnostic and Interventional Radiology" Volume 4 No. 3 2010 pp. 61 - 66. 2. article "MRI diagnostics in obstetrics" Platitsin I.V. 3. materials of the site www.az-mri.com. 4. materials from the site mrt-piter.ru (MRI for pregnant women). 5. materials from the site www.omega-kiev.ua (Is MRI safe during pregnancy?).

From article: "Obstetric aspects of acute cerebrovascular disorders during pregnancy, childbirth and the postpartum period (literature review)" R.R. Arutamyan, E.M. Shifman, E.S. Lyashko, E.E. Tyulkina, O. V. Konysheva, N.O. Tarbai, S.E. Flock; Department of Reproductive Medicine and Surgery, FPDO, Moscow State University of Medicine and Dentistry. A.I. Evdokimova; City Clinical Hospital №15 named. O. M. Filatov; Department of Anesthesiology and Reanimatology, FPK MR, Peoples' Friendship University of Russia, Moscow (journal "Problems of Reproduction" No. 2, 2013):

“In MRI, ionizing radiation is not used, no harmful effects on the developing fetus have been noted, although the long-term effects have not yet been studied. A guideline recently published by the American Radiological Society states that pregnant women can have an MRI scan if the benefits of the study are clear and the information cannot be obtained using safe methods (such as ultrasound) and cannot wait until the patient is pregnant. Contrast agents for MRI readily penetrate the uteroplacental barrier. Studies of the removal of contrast from the amniotic fluid have not been carried out, just as their potentially toxic effect on the fetus is not yet known. It is assumed that the use of contrast agents for MRI in pregnant women is justified only if the study is undoubtedly useful for making the correct diagnosis in the mother [read the source]. "

From article"Diagnostics of acute disorders of cerebral circulation in pregnant women, parturient women and women in labor" Yu.D. Vasiliev, L.V. Sidelnikova, R.R. Arustamyan; City Clinical Hospital №15 named. O. M. Filatova, Moscow; 2 State Budgetary Educational Institution of Higher Professional Education "Moscow State University of Medicine and Dentistry. A.I. Evdokimov "of the Ministry of Health of Russia, Moscow (magazine" Problems of Reproduction "No. 4, 2016):

“Magnetic resonance imaging (MRI) is a modern diagnostic method that allows you to identify a number of pathologies that are very difficult to diagnose when using other research methods.

In the first trimester of pregnancy, MRI is performed for health reasons from the mother, since organo- and histogenesis has not yet been completed. There is no evidence that MRI has a negative effect on the fetus or embryo. Therefore, MRI is used for research not only in pregnant women, but also for fetography, in particular, for examining the fetal brain. MRI is the method of choice during pregnancy if other non-ionizing medical imaging is not sufficient, or if you need to obtain the same information as radiography or computed tomography (CT), but without the use of ionizing radiation.

On the territory of Russia there are no restrictions for MRI during pregnancy, however, the WHO Commission on Non-Ionizing Radiation Sources does not recommend any exposure to the fetus from the 1st to the 13th week of gestation, when any factor can somehow affect its development.

In the II and III trimesters of pregnancy, the study is safe for the fetus. Indications for MRI of the brain in pregnant women are: [ 1 ] ACVA of various etiology; [ 2 ] vascular diseases of the brain (anomalies in the development of blood vessels in the head and neck); [ 3 ] trauma, bruises of the brain; [ 4 ] tumors of the brain and spinal cord; [ 5 ] paroxysmal conditions, epilepsy; [ 6 ] infectious diseases of the central nervous system; [ 7 ] headache; [ 8 ] cognitive impairment; [ 9 ] pathological changes in the sellar region; [ 10 ] neurodegenerative diseases; [ 11 ] demyelinating diseases; [ 12 ] sinusitis.

To perform MRI angiography in pregnant women, the administration of a contrast agent in most cases is not necessary, unlike CT angiography, where it is required. Indications for MR angiography and MR venography in pregnant women are: [ 1 ] cerebrovascular pathology (arterial aneurysms, arteriovenous malformations, cavernomas, hemangiomas, etc.); [ 2 ] thrombosis of large arteries of the head and neck; [ 3 ] thrombosis of the venous sinuses; [ 4 ] identification of anomalies and variants of development of the vessels of the head and neck.

There are few contraindications for the use of MRI in the general population and in pregnant women in particular. [ 1 ] Absolute contraindications: an artificial pacemaker (its function is disturbed in the electromagnetic field, which can lead to the death of the examined patient); other electronic implants; periorbital ferromagnetic foreign bodies; intracranial ferromagnetic hemostatic clips; pacemaker conductive wires and ECG cables; pronounced claustrophobia. [ 2 ] Relative contraindications: I trimester of pregnancy; the patient's serious condition (it is possible to conduct an MRI when the patient is connected to life support systems).

In the presence of heart valves, stents, filters, the study is possible if the patient provides accompanying documents from the manufacturer, which indicates the possibility of conducting an MRI with an indication of the magnetic field strength, or an epicrisis of the department where the device was installed, which indicated the permission conducting this survey ”[read the source].