Magnetic Resonance Imaging (MRI)
During the tomography, many patients are scared by the noise made by the device. This noise cannot be removed. The greater the power of the device, the higher the noise it emits. Therefore, often patients are offered to wear headphones.
Also, if suddenly you feel that your health is deteriorating during the scan, then you can click on the alarm button that you are given before the examination. You need to press the button only once, and the laboratory assistant will immediately approach you. If you are very worried before the procedure, then you may well bring along someone close to you. However, this must first be discussed with a clinic specialist.
How to get an MRI scan
Brain MRI is a harmless procedure that you don’t need to be afraid of. If you are very worried, then you should drink a sedative one hour before the event. Give up strong drugs that make you sleepy. After all, if you fall asleep during the procedure, the results of the examination will be inaccurate. In general, an MRI of the brain does not cause discomfort, because modern technology is now at its best.
During the examination, you should lie still. Even minimal movements can distort the quality of the image, as a result of which the doctor will not be able to give you the correct diagnosis.
How to prepare for the study
In order to stop being afraid of this procedure, you need to learn as much as possible about it and ask all your questions to your doctor. Also, a good way to overcome fear is to realize its baselessness. The day before the examination, talk with your loved ones, tell us your concerns. For example, if a patient is worried that in the tomograph his condition may worsen and there will be nobody to help him, then his relatives can assure him, then this situation is completely excluded. The research process is always closely monitored by an MRI operator and a doctor.
Before going to the scanner room, the patient can ask all the questions of interest to the doctor. An MRI scan is a completely harmless procedure for the human body that you should not be afraid of. In the event of any unforeseen situation, the doctor who oversees the study will always help you. Therefore, the fear of the procedure is an unjustified excitement.
Is it scary to do an MRI? Is it noisy there? MRI in the presence of tattoos - does the skin burn? How to get magnetic resonance imaging with a discount of almost 45%? Can I do an MRI for free? Contraindications, indications, prohibitions and nuances. MRI of the three parts of the spine.
4 years ago my back ached. And since I was used to “enduring” pain, I didn’t even have thoughts to undergo examination, or at least consult a doctor. And at that time I was not at all up to that - healed old, more terrible wounds, so to speak. Then two years later there was an equally terrible fall from the stairs - just flat on the back of the stairs on the edges,
Fortunately, the skull was not miraculously split. And again, no examinations. Well, to top it all, dragging / rocking the child provoked another pain blow and then I already realized that it was time to get ready for an MRI. However, she did not dare to go through it during the war. And after she had once worked as a draft horse and, imagining herself a weightlifter, dragged the heavy trunks to the 4th floor and back, the back came to an end. She prayed for an examination)
Prices in our city for magnetic resonance imaging, in particular, of each spine, begin from 2 500 rub.And since each time I was blocked by different departments - then the lumbar, then the thoracic - it is clear that the procedure turned out to be clearly not budgetary, which slowed down its passage.
But to my incredible luck, one private clinic threw coupons at Biglion at a 30% discount! Plus, I was lucky enough to get on a cyber Monday in honor of June 12 and get an additional 20% discount from the site itself. As a result, instead of 2,500 rubles, each section of the spine cost only 1,400 rubles!Thus, the thoracic and lumbosacral spins came out at 2,800 rubles, and I decided to make the cervical one a little later and already without an extra discount - for 1,750 rubles, well, I immediately took off the Biglion cashback of 70 re, it turned out 1,680 p) Saving hoo what - instead of 7 500 rubles as much as 4 480 rubles.
☆☆☆ So what is an MRI? ☆☆☆
Magnetic resonance imaging (MRI) is one of the most dynamically developing methods of radiation diagnostics. MR imaging allows you to get images that are comparable in quality with histological sections in a few minutes. The most important advantage of MRI over other diagnostic methods is the absence of ionizing radiation and, as a result, the complete exclusion of its effects. MRI has a high soft-tissue contrast and allows you to conduct research in any planes, taking into account the anatomical features of the patient’s body, and if necessary, obtain three-dimensional images for an accurate assessment of the pathological process. It is the only non-invasive diagnostic method with high sensitivity in detecting edema and bone infiltration.
Thus, clear difference between MRI and X-rayand other examinations in that the body is not exposed to any radiating effect. Plus, an x-ray is mainly good for examining bones, and MRI is subject to all kinds of tissues. Yes, and the x-ray is “flat”, while magnetic resonance imaging allows you to obtain three-dimensional images of the studied areas and notice microscopic changes. But X-rays also have advantages over MRI, which I will indicate below.
The following types of MRI tomography are distinguished:
Appointed if manifested:
- persistent headaches and neck pains,
- loss of consciousness,
- head injury
- examination after a stroke or heart attack,
- existing bouts of impaired consciousness,
- suspected swelling
- birth injury,
- hearing impairment
- vision or smell,
- loss of sensation.
This procedure is called MR angiographyand with its help you can identify:
- aneurysms and pathological anastomoses,
- vascular stenosis and occlusion,
- vascular malformations
- atherosclerotic changes.
- venous sinus thrombosis
Each department is examined separately - there are 3 of them: cervical, thoracic and lumbosacral. Identify protrusion, hernia, curvature of the spine.
Specifically, in my clinic, only the abdominal cavity is examined. I don’t know why. In general, with the help of MRI, ALL organs are checked.
Here the MRI is just on top:
The main method in the modern diagnosis of traumatic injuries, degenerative, inflammatory and tumor diseases and joints, and surrounding soft tissues. This is the only non-invasive method for visualizing the soft tissue component of the joint: tendons, ligaments, menisci, cartilage, periarticular bags.
This can include both examination of the spine and other types of bones in case of injuries (fractures, cracks) and other negative processes.
☆☆☆ How to get an MRI for free? ☆☆☆
A specialist in a district clinic can give you a referral if there is a reason, but we all know how sometimes it can be difficult to get an appointment for such expensive procedures from our free medicine. Moreover, if I had an MRI for a fee a day after the recording, then the “freebies” were recorded with me only at the end of the next month.And you can die without waiting. And I had real reasons to hurry, since soon I would have acquired one of the contraindications for MRI! But more on that below.
☆☆☆ MRI preparation ☆☆☆
No special required. There are general recommendations - for example, to do it on an empty stomach and not to drink for 4 hours, but personally no one made such requirements to me. For abdominal examinations, abstinence from food and water is already strictly necessary, but MRI of the bladder is done after it is full.
You can take a bathrobe or shirt with you and completely change your clothes before the examination. In our clinic, disposable clothing is not provided, in others - perhaps there is such a service.
Well, I recommend visiting the toilet before the procedure - still you have to lie there from 20 to 40 minutes.
☆☆☆ Contraindications to MRI ☆☆☆
They are divided into relative and absolute. The first include:
- insulin pumps
- nerve stimulants
- non-ferromagnetic implants of the inner ear,
- heart valve prostheses (in high fields, with suspected dysfunction)
- hemostatic clips (except cerebral vessels),
- decompensated heart failure,
- first trimester of pregnancy (currently insufficient evidence has been collected on the absence of the teratogenic effect of the magnetic field, but the method is preferable to x-ray and computed tomography)
- claustrophobia (panic attacks while in the apparatus tunnel may not allow research)
- the need for physiological monitoring
- severe / extremely serious condition of the patient for the underlying / concomitant disease.
That is, the decision to carry out the procedure, if any or not, will be made by the doctor in each case.
FROM absolutecontraindications you will not be allowed to undergo an MRI:
- installed pacemaker (changes in the magnetic field can mimic the heart rhythm).
- ferromagnetic or electronic middle ear implants.
- large metal implants, ferromagnetic fragments.
- ferromagnetic devices Ilizarov
And here it is worth mentioning that prompted me to do an MRI urgently: the approaching day of the installation of a dental implant. Although modern implants are made of alloys that are unlikely to smear the picture of the study, I don’t want to risk it. To give at least 2,500 rubles and get distorted results - no, thank you. It is clear that if you do an MRI of the legs, then the implant will not play a role, but for the examination of the brain or cervical spine, it will matter. Much also depends on the equipment - there are MRI devices that reconfigure to metal, and there are models in which this is not provided. And I suspect that in our city, well, obviously not super-sophisticated devices. In the future, most likely, I should give preference computed tomography.
But this point about tattoos scared me a lot:
MRI is also contraindicated in the presence of tattoos made using dyes containing metallic compounds. Widely used in prosthetics, titanium is not a ferromagnet and is practically safe for MRI, with the exception of tattoos made using dyes based on titanium compounds (for example, based on titanium dioxide).
As far as I remember, one of my tattoos just contains white pigment, which contains titanium dioxide. I read that the area of the tattoos can heat up or even burn. Fear suffered, of course. But the MRI operator confirmed the information that I read in alternative articles on this topic - the presence of a tattoo (no older than 20-30 years old) is not an absolute contraindication now. It used to be pricked by the fact that it only came to hand and the paints were very saturated with metals. Well, immediately the spoiler - nothing burned or burned)
☆☆☆ Clinic visit ☆☆☆ MRI scan ☆☆☆
I recorded on the phone, I was asked several questions to exclude the presence of contraindications, they said to take a passport and a coupon. I visited the clinic for the first time and I was asked to come up 10 minutes earlier to draw up a card.
The hall turned out to be small and quite cozy. A TV was working on the wall, and a cooler was located under it. From excitement, I immediately occupied him and only then thought that in the midst of being in the apparatus, water enthusiasm might come back to me)
At the reception were female administrators / receptionists. At the counter, I filled out a questionnaire, where I already answered in more detail questions directly related to MRI.
They gave me a ticket and told me to wait a bit. The waiting area is an "island" of two sofas. Very comfortably.
I put on my shoe cover and began frantically waiting for a call to my office.
There was a poster on the door prohibiting use in the room where the MRI device is located, mobile phones and electronic devices, bring magnetic cards there.This, by the way, is in your own interests, since if in the immediate vicinity of this machine appears something like this, then it will simply die - it will be demagnetized. Thus, my relative lost a camera, all plastic cards and a phone - thoughtlessly went to the device with a bag and magnetized it to its wall, and all its contents died without the right to restoration)
Also before the procedurewithout fail, it is necessary to take off all metal objects (watches, jewelry, piercings), get rid of clothing parts with metal parts.Simply put, you should not have a gram of metal! The only exception is the shoes - I examined the spine, so the legs remained far beyond the working part of the machine and the presence of metal locks on the sandals was acceptable. If you do an MRI of the lower leg, for example, then, of course, you have to take off your shoes.
The room is divided into a transparent glass wall in 2 parts- in the first one there is an MRI device and nothing more, and in the second there are operators and specialists, there is also a changing room where you leave bags and other things.
As an honest and obedient, and still very afraid girl, I turned off the phone and did not even get it in the control room. Therefore, I took the MRI photo from the clinic website and put it in a collage. Everything looks like this in reality, only a high stand with two wide steps is still attached to the device, otherwise it will jump high on the table.
Car brand - Siemens Magnetom. Magnetic induction - 1.5 Tesla.This is far from the highest among devices.
The surface of the table is covered with a disposable diaper. At the head is a concave cushion, so that the head will be securely locked. They put me on the table, gave me a pear - like a panic button - if it gets bad, you should squeeze it and they will come to save you.
Warned that in no case move.
The operator put on my big headphones, pressed the buttons on the car body and I smoothly, head first, went on the table into the mouth of the device,
like Gretel in the stove on a witch's spadeand the girl left the room and closed the door.
☆☆☆ MRI process ☆☆☆
The hole in the device is cone-shaped, the further you drop in, the more it narrows more and more, but does not end with a blank wall - there is a gap. Also, nothing closes in front, so it wasn’t scary at all - I saw the second room and the operator through the glass wall, so I didn’t even have a hint of panic. Claustrophobia and similar conditions do not suffer.
The first moments were quiet, thenthere was a cracking, knocking, all this alternated, changed dramatically, it looked like the sirens of police cars, then swotting a jackhammer - in a word, the atmosphere was akin to the construction - one thousand, three thousand, tr, tr, bang bang.There were periods of silence. A child of the 90s and, concurrently, a child of numerous construction projects at that time (practically, in the literal sense) - I was absolutely not afraid. Well popping, well, knocking. you think about it. The sounds, however, were quite loud, and this is in the headphones! By the way, I understood their jamming effect only when I left the device and the operator turned to me when they were still with me - I barely heard her, although she was leaning over me!
During the operation of the machine, I felt a subtle vibration. Otherwise, there were no more remarkable sensations.
On the first visit I examinedimmediately 2 parts of the spine- thoracic and lumbosacral. When they did chest, I drove into the device very close, but with the lumbosacral they pushed me away. Therefore, each department is examined separately - approximately 15-20 minutes each.
Thus, the entire procedure with changing clothes and dressing took 40 minutes. Plus, for half an hour, I waited in the lobby when the results would be returned to me - a specialist’s report and a recording disc.
In conclusion, everything is described in detail - in which vertebrae what problems are found, whether the structure is unchanged, where which curvatures are - everything is clear. Below is a postscript that a neurologist consultation is required. You can visit it for a fee in the same clinic, or you can go to the freebie. But that's another story)
In particular, I was diagnosed with - osteochondrosis and prescribed injections
☆☆☆ Conclusion ☆☆☆
As a result, for me, MRI was not a terrible procedure at all, yes, noisy, but quite tolerable, I even tried to brazenly take a nap.
➕ I'm not afraid of enclosed spaces, so being in a narrow conical pipe did not scare me.
➕ It is not painful, not nasty and imperceptible in essence.
➕ Nothing happened to my tattoos. Yoo hoo!
➕ I received detailed conclusions about the condition of the 3 departments of my spine, identified the causes of pain and I was prescribed adequate treatment.
▬ Pleasure is expensive. Even more. Judge for yourself, at the full price for 3 departments, I would have given 7,500 rubles.
▬ It’s better not to go with claustrophobia there, IMHO.
▬ Many can be frightened by noise.
▬ If a person is prone to jerking / tremors / tics, then he is unlikely to be able to lie still for 15-20 minutes motionless. And here comes the advantage of x-rays, which is done within a few seconds.
▬ Accordingly, MRI will be problematic for a small child. Children under 5 years old are administered under anesthesia. And I understand why. Who would like to lie motionless in some kind of pipe?) Yes, even rattling.
I can not recommend this procedure. Decide on the presence / absence of contraindications and go! MRI is the most accurate and painless method for diagnosing a wide variety of diseases and disorders in all types of tissues, it’s a pity, the prices for examinations are high, and the car is noisy.
Perhaps you will find useful reviews on dietary supplements and drugs:
MRI diagnostics: why do you need to conduct a study
The MRI procedure is a non-invasive method of research, providing the ability to obtain the most accurate information about the condition of internal organs, systems, tissues, blood vessels, tendons, bone tissues and more. The study allows you to diagnose diseases in all human tissues, for which it has become widespread throughout the world.
The principle of operation of a magnetic resonance imager is based directly on the creation of a high power magnetic field. Electromagnetic vibrations are recorded, on the basis of which a corresponding picture of what is happening inside a person appears. A device called a tomograph performs such a function. The tomograph is equipped with a high-precision computer, which allows you to analyze magnetic vibrations and give the corresponding results in the form of visualization.The results of the study are displayed on a computer screen in a three-dimensional image, and are also recorded in the form of images that the patient receives in his hands at the end of the diagnosis.
The tomograph is a large capsule that has free space inside. This space is intended for the patient to fit inside. The capsule shell is equipped with a powerful magnet, through which a constant magnetic field is created. An MRI scan is often used when an X-ray, ultrasound, or computed tomography does not provide accurate results.
It's important to know! MRI is also used for prophylaxis for prophylactic purposes, but it is important to know that magnetic resonance imaging is one of the most expensive diagnostic methods.
In which cases the doctor prescribes the passage of an MRI
An important advantage of the diagnosis of MRI is the complete safety and harmlessness of the technique. In the course of the study, X-ray radiation is not used, since the diagnostic process is built on the effect of magnetic fields. The magnetic field is safe for humans, which has been proven by numerous studies conducted by animal scientists. Every day, a person is faced with the influence of electromagnetic fields, which do not harm our body.
It's important to know! The MRI procedure is carried out in order to carry out the most detailed examination. Sometimes, in order to diagnose some diseases at the stage of their development, resort to the use of contrast agents.
What is a contrast agent, and why is it necessary when conducting a study? The contrast agent is presented in the form of gadolinium salts. This component is injected mainly into the vein in the required amount. It is immediately worth noting that the contrast is absolutely safe and harmless. The only contraindication to its use is the presence of signs of individual intolerance. After contrast has entered the body, the blood delivers it to all organs and tissues. Staining of the investigated organ increases the effectiveness of the diagnosis up to 100%.
Usually, a doctor appoints a study if he has doubts about making an accurate diagnosis. In this case, the doctor may prescribe an X-ray, computed tomography or ultrasound scan, but these types of studies have a significant drawback - the inability to obtain the most accurate results. Often, it is on the basis of preliminary results of these studies that a decision is made to conduct additional diagnostics of MRI. Magnetic resonance imaging is used not only as prescribed by a doctor, but also of their own free will. In this case, the patient must understand what specific area of the body he wants to explore. The results should be decoded by the doctor, since the diagnostician writes only a conclusion.
It's important to know! Diagnosis of MRI can be carried out in as many times as necessary, due to the safety of the technique.
The main types of pathologies diagnosed on MRI
Diagnostics by magnetic resonance imaging can be carried out as the whole organism, and individual organs. A full study of the body takes a long time, so experts recommend that the diagnosis be done in stages, which increases the likelihood of detecting serious pathologies. Consider the main body parts that are subject to diagnosis using a magnetic resonance imager.
- MRI of the brain. One of the most common types of diagnosis, which makes it possible to determine the presence of tumors, identify problems with blood vessels, the presence of aneurysms, as well as various kinds of neoplasms.
- MRI of the spine. The procedure is prescribed primarily to identify the causes of pain syndromes.The spine, like the brain, is one of the important parts of the body that are prone to more trauma. Diagnosis of the spine allows you to get information about the condition of the intervertebral discs, the presence of hernias and tumors, and also makes it possible to track the speed of the cerebrospinal fluid.
- MRI of the abdomen. Allows you to conduct a full study of all organs, as well as visualize them. The organs of the abdominal cavity are susceptible to negative effects from the food consumed, so timely diagnosis of MRI helps prevent serious pathological manifestations: tumors, neoplasms, ulcers.
- MRI of the joints. Joint MRI is prescribed when there is a need to diagnose obsolete injuries and deformities. An x-ray is usually initially prescribed, but if it is not possible to make a correct diagnosis against its background, then resort to an in-depth examination of MRI.
Diagnosis of MRI allows the study of hands, lower and upper extremities, feet, eyes, ears and other organs and parts of the human body. It is important to note that the MRI procedure is useless if you need to examine the intestines and kidneys with urolithiasis. In all other cases, MRI is the leader among research procedures that save hundreds and even thousands of patients every day.
MRI with contrast: preparation for the study
There are no strict rules for preparing for the diagnosis of most organs. There are certain recommendations:
- it is recommended to come to the procedure with contrast on an empty stomach, restricting food intake two to three hours before the appointed time, this helps to prevent the development of nausea
- if intravenous sedation is planned, the patient must comply with the requirements of the anesthetist,
- Before examining the pelvic organs and abdominal cavity, it is necessary to adhere to a diet with the exception of gas-forming products,
- on the eve of the diagnosis of the genitourinary and digestive systems, preparation of the intestine is required (a laxative or enema is used), the last meal should take place 6 hours before the visit to the clinic, liquids - 4.
Before MRI with contrast, you need to refrain from eating food and fluids.
Contrast drug penetrates not only into the blood, but also into breast milk. During lactation, breastfeeding can be resumed no earlier than 24 hours after the injection, so you should prepare in advance and stock up on food for the baby. Unsuitable milk is decanted and poured.
Why do MRI with contrast?
Intravenous amplification is a way to improve diagnostic reliability. Contrast helps:
- differentiate different anatomical structures,
- identify areas of neovascularization (pathological proliferation of blood vessels accompanying the formation of tumors),
- consider hollow, parenchymal organs,
- examine blood vessels
- to study the functions and perfusion of organs.
If oncology is suspected, magnetic resonance imaging with contrast allows you to:
- specify the structure of the pathological focus or region of the altered MR signal,
- determine the exact number of affected areas, the degree of invasion of the surrounding tissues, distant prevalence (metastases),
- follow the dynamics of change.
Using contrast, you can evaluate the effectiveness of therapy and monitor the condition of tissues and organs after surgery.
MR-angiogram of the vessels of the head and neck
The main goals of using intravenous enhancement:
|MRI of the brain, spinal cord and neck organs|
|MRI of the chest|
How do MRI with contrast
Magnetic resonance imaging. To the left of the device is a system for automatically injecting contrast agents into a vein
Before the study, the patient fills out a questionnaire, which indicates information about:
- transferred operations
- kidney disease
- wounds with metal objects: bullets, fragments, shavings, etc.,
- implanted devices (documents for installed devices must be provided),
- dentures (joints, limbs, heart valve, eyes),
- the presence of a hearing aid, dental orthodontic and orthopedic products,
- tattoos, piercings,
- history of epilepsy, spontaneous seizures,
- fear of confined or confined spaces
- allergic reactions to drugs, in particular, contrast agents for CT and MRI.
Women should warn about pregnancy, breastfeeding, the presence of an intrauterine contraceptive device.
In preparation for an MRI scan (normal and with contrast), it is necessary to remove makeup from the eyes, remove the denture, hearing aid, glasses, jewelry, hairpins, hair clips, and women need to wear a bra. Loose clothes without metal fittings are put on the procedure. Some clinics have disposable shirts or bathrobes.
It is forbidden to bring mobile phones and other electronics, keys, wallets, payment cards, etc. into the room where the magnetic resonance tomograph is located. items.
MRI with contrast
To compare the results obtained and a more complete clinical picture, contrast is used after performing an ordinary MRI. The procedure involves two methods of drug administration:
- simultaneous - they inject a full dose of the drug into a vein and take pictures right after that,
- bolus: the substance enters the circulatory system gradually, synchronously with the scanning of the area of interest - this method allows you to monitor the processes occurring in the body in real time.
Comparison of native and contrast MRI scans
During the procedure, the patient is in a tunnel-shaped capsule of the apparatus on a pull-out table. Depending on the zone in question, a person should spend 30 minutes to an hour in the tomograph. To avoid distortion of pictures, you can not move.
The unit makes loud noises. If the examination does not include listening to the doctor’s instructions, the patient is offered to use headphones or anti-noise inserts.
The tomograph is equipped with a panic button and a personnel communication device. With a deterioration in well-being, the subject can stop the process at any time.
First, a little simple theory. MRI (MRI in English) is a method of obtaining a layered image of the internal structure of an object. Roughly speaking, MRI helps to obtain virtual sections of tissues and organs of a living person without invading his body - this is the so-called non-invasive method.
It is based on a phenomenon called nuclear magnetic resonance (NMR), and in the past, the letter “I” was added to the abbreviation MRI at the beginning (NMR was spoken in English instead of MRI). But they decided to get rid of the word “nuclear” for a simple reason - so as not to irritate the people, although there is nothing in common with bombs or radioactive elements of the periodic table.
If this somehow helps to understand the processes underlying the phenomenon, we are talking about measuring the electromagnetic response of atomic nuclei excited by electromagnetic waves of different combinations (therefore, by the way, a rhythmic sound of different tonality is heard) in a constant magnetic field of high tension, indicated in tesla.
Field strength affects the quality of the resulting image. The lower the power, the narrower the range of applicability of tomographs, which, in turn, are divided into several basic types - from low-floor to ultra-high-floor (from the word "field", not "floor").
We will not argue that the more powerful the better. Let's put it this way: the more powerful, the more versatile and accurate the system. But the more universal it is, the higher its price, which can amount to hundreds of thousands of dollars and even exceed a million.
In low-floor fields, the field strength is up to 0.5 T. It is believed that such tomographs without contrast can provide basic information. This is followed by medium-floor (1 T), high-floor (1.5 T) and ultra-high-floor (3 T). There are more powerful ones, but ordinary medical facilities do not need them.
“Many people ask, what is the difference between 3 T and 1.5 T? The fundamental difference is in the detail and clarity of the picture, " - explained the head of the office of the MRI center “Tomography” Vesta Korolenok. As an example, she talked about a patient with a small tumor: an apparatus with 1.5 T did not notice her, and at 3 T they saw a pathology by sending a person to one of the RPRC.
There are also closed and open tomographs. One of the features of the first, which are more common, is the restrictions on the patient’s dimensions - a very complete person simply will not fit in the “pipe”. In addition, those suffering from claustrophobia may feel uncomfortable in a confined space, where you can not move. Open tomographs allow studies of individual joints, the spine and even the head. The weak side of open-type tomographs is lower resolution: they are all low-floor and have a magnetic field strength of not more than 0.35 T.
What can not be done
You can get inside the tomograph, but not everyone. First of all, it is not possible for holders of implants of different types to go there: from pacemakers to hearing aids. There are several reasons: firstly, the magnetic field can damage and / or disrupt the operation of the implant, secondly, there is a chance to cause temperature or other injury to the patient, and thirdly, the presence of the implant will negatively affect the scan results.
The same applies to metal in the body - “knitting needles” and pins, shots and fragments, surgical clamps and similar elements (titanium is an exception).
In some cases, when scanning, contrasting preparations are used, which additionally increase the clarity of the image. Their components can cause allergies, they are usually contraindicated in pregnant women, as well as during lactation.
The “Tomography” has an ultra-high-floor Siemens Magnetom Spectra 3 T. The unit cannot be called light: its curb weight is about 7.3 tons with a tunnel length of 173 cm. The system allows up to 120 coil elements to be used to cover the entire anatomical zone (for example, the entire central nervous system). Used proprietary software Siemens, which primarily affects the quality of the scan and the final image with slices 0.5-1 mm thick.
The examinee is dressed in a disposable dimensionless suit, in which they are sent to the mouth of the tomograph. A person is laid on a table (this is the name of the structure, which is then hidden in the tunnel). In order to somehow protect the ears from loud sound, headphones are put on the head, from which light music sounds. If you wish, you can arm yourself with your own track list or audiobook.
This surprised: what kind of headphones, if there should be no metals? It's simple - the sound is transmitted to the funnel headphones not through wires, but through pipes made of elastic plastic, so the compositions sound like from a well. It is worth noting that the accessory is not fully capable of drowning out the “tunes” of the tomograph.
It is impossible to jump out of the apparatus, therefore, just in case, a pear is put into the patient's hand (correctly - a signaling device). In case of panic attacks or for any other reasons, it is enough to squeeze it, and the radiologist who controls the process in the room nearby (in the so-called control room) will have an extremely loud alarm.
“It would seem that everything is fine, the patient was laid down, but only had time to close the door, when the pear had already been pressed,” - Vesta tells us. According to her, there are people who get tired in the process, and it can last up to two hours. Therefore, sometimes a break is taken so that the patient can rest. This primarily concerns a study such as whole body MRI.
Quite often there are people with claustrophobia, panic disorders. In this case, it is recommended to find out from a specialist about all stages of the study and see the device itself.
Scanning may take some time, in our case it lasted about 20 minutes. The second 10 (or all 19) lasted forever - after all, you can’t move, but really want to. “Houston, we have a problem,” - stuck in my head at the moment when my nose began to itch on the rise (and this happened when I thought: “The main thing is not to brush your nose”) But a light breeze from the fan somewhere above his head helped to hold still until the end of the procedure.
There is nothing to do in the tunnel - there is nowhere to look, since there is a coil (?) Almost in front of the nose, similar to a holding device. It remains to cover your eyes and listen to “magnetic resonance music”: the system, collecting data, buzzes and “sings” in different tones, but always rhythmically (in fact, these are ultrafast vibrations). Sometimes she stops talking and you think: "It's over." But the pause, which is required to reconfigure the system, passes, and the rhythm starts again. They say that some manage to fall asleep in the process - this can only be envied.
By the way, the sound of the tomograph depends on the types of coils involved and the current program.
“Leaving” the tunnel, I want to jump up and go - because of the still position and loud sound, a short feeling of disorientation arises. The main thing is not to rush (yes they will not allow you).
After everything I experienced, there was a desire to do it like in a movie - go to the tomograph with a gun (this is shown regularly in action movies). But the weapon was not at hand, so the experiment remained a dream - to check whether the gun is magnetized, did not work.
How long can a scan take?
- In the center “Tomography” - up to two hours. This is a full body MRI with contrast. As mentioned above, in such cases, we break up the study into parts.
Least of all time is spent examining ordinary joints, such as knee joints. In a standard situation without pathologies it lasts no more than 15 minutes for one joint. But this is the time that the patient was directly in the tomograph without taking into account data analysis.
Siemens is constantly developing new software. It allows you to reduce the time for some types of diagnostics. For example, you can speed up the scan of joints - up to 8 minutes, and the brain - up to 6-10.However, new options in the software require careful study, study and optimization of existing research protocols before implementation.
Are there any problems that are frankly difficult for the tomograph?
- When examining the abdominal cavity, for example, and if we work in automatic mode, the device adjusts to the movement of the diaphragm, reading data at a certain position. This significantly increases the study time. The process can be accelerated, but the patient will have to hold his breath for 20 seconds many times. Physically, this is not easy.
There are no any restrictions for the device when it is fully equipped with coils. For example, we do not yet look at the heart and conduct breast research. But this year the necessary components will be purchased.
Why can't you move?
- When a person moves, the picture is blurry. In some cases, in order to obtain a high-quality image, it is necessary to adjust the tomography program. We need to clearly see the walls of the same vertebrae, structure - this allows us to determine the presence of pathology. When a person moves, even the contours are lost, the diagnosis is seriously difficult.
With some types of scanning, small and rare movements will not become a problem, but in certain cases - when blurry scans fall into place with a hernia or other changes - we are forced to repeat a series to get clear pictures.
Do you need to compress your teeth so that the fillings do not fly out?
- As for dental issues, there are no contraindications. Rather, there are technical nuances. If it's a brain study, an artifact seal, pin may fall into the study area. We then build the program so as to bypass such places and get an image of the desired area.
Patients with tattoos made about 20 years ago, when the ink had a high metal content, a barely noticeable heating is possible. Extremely sensitive patients are found, they usually talk about such things.
Fears, as a rule, arise in those who undergo a similar procedure for the first time, as well as in age-related patients.
According to Vesta, MRI allows you to see what is left behind the frame of x-ray images. At the same time, a picture with fractures of the vertebra and sacrum is displayed on the screen of the doctor's workstation. “This trauma on an X-ray made at the clinic is not visible”, - explains our interlocutor.
In addition to the technical part, a set of programs for research and data analysis has a direct impact on the diagnostic process.
The device takes a picture in three planes: coronal (along the body from front to back), sagittal (from right to left) and axial (from top to bottom). If necessary, the image can be visualized in 3D mode.
Initially, a set of programs (or a set of sequences) comes into play that provides information, in fact, scanning. The choice is based on what area will be studied: for the brain - its own set, for the joints - its own and so on. In addition, the algorithms differ depending on the age of the patient.
In automatic mode, after receiving the data, the information is transmitted to the doctor’s workstation. He, “armed” with his software, looks at the results, corrects them if necessary and works with an image that allows you to see the whole picture or its details, that is, the specialist has an exact virtual model (or map) of the studied area, organ.
There are highly specialized sets of programs, which include, for example, the perfusion algorithm. More often it is used in the event of tumors, in particular, the brain, providing information that allows you to determine the degree of malignancy.
Of course, not all software will be equally in demand. “For example, studies such as tractography (building neuron connections in the brain right down to the smallest cells - you get a beautiful color three-dimensional picture) or functional MRI, which highlights the areas of the brain involved in certain movements, are interesting, but they are mainly used to diagnose complex and rare diseases of the central nervous system ", - explains Vesta.
It is believed that MRI can replace some painful or harmful diagnostic diagnostic procedures. A specific example is mammography, which you have to resort to when ultrasound cannot be done for a number of factors, including due to age. The method is highly informative, but extremely uncomfortable, as it requires serious compression of the mammary gland, and in the presence of pathology it can be very painful. “An alternative could be an MRI. Currently, in Europe, an MRI scan of the mammary glands is displacing mammography from the life of mammologists. This method has huge advantages and great prospects, " - the interlocutor notes.
“Previously, computed tomography with contrast was mainly used - this is a huge dose of radiation. And if you need to do this examination several times during the year ... Especially since all X-ray contrast agents are quite allergenic, ” - says Vesta.
Key Benefits of MRI
Why do you need an MRI if you have x-rays or an ultrasound scan? MRI is prescribed by the attending physician if he has doubts about the preliminary diagnosis. Techniques such as radiography and ultrasound, can not get a complete picture of what is happening inside, so individually, the specialist can prescribe an MRI. If the picture of the disease is clear, then the doctor may prescribe an MRI after therapeutic treatment or surgery.
Like any diagnostic method, the magnetic research technique has its pros and cons. The advantages of MRI techniques include:
- Harmlessness and safety. The procedure is so safe that it can be performed on children.
- High informativeness. After the diagnosis is completed, the doctor can make an accurate diagnosis at 100%.
- Non-invasiveness. To conduct the study, the patient does not need to introduce various devices or objects into the body. During the diagnosis, the only drawback is the need for a stationary lying on the apparatus table for a long time.
- Efficiency. Despite the high cost of diagnosis, the results of the study provide accurate information about the presence of pathologies in humans.
There is only one drawback with MRI - this is the high cost of the procedure. If during the study it is necessary to use a contrast medium, then the cost increases several times.
It's important to know! MRI is not used in cases where it is necessary to find out the presence of pathologies in the stomach, lungs, intestines and bone tissues.
How is an MRI performed?
The technique is so safe that the patient does not need to prepare for it. How does the process of magnetic resonance imaging, every patient who has signed up for diagnosis wants to know. It all starts with the fact that on the day when the procedure is prescribed, a person should come to the clinic 10-15 minutes earlier than prescribed. This time is allocated so that initially the patient can familiarize himself with the contract, which states that he will not have any complaints if something goes wrong. Such a program is especially often practiced in private clinics.
After this, the patient needs to take off clothes that have metal elements. Usually the procedure is carried out in a special medical gown. The patient is warned in advance about the need to purchase such a dressing gown. When everything is ready, the patient rests on the sliding table of the tomograph, after which the diagnostician fastens it with straps.This is done so that the patient does not move during the study, since this can not be done.
It's important to know! If the patient will move during the study, the results will be blurry and inaccurate.
After the patient is ready, the diagnostician places the table with the patient in a capsule, after which he leaves the room. In order to avoid deterioration of the patient’s well-being, the specialist gives him a special device in his hand, which he must press if he feels unwell. The duration of the diagnosis lasts from 20-30 minutes to 2 hours, which depends on the study area, as well as the need for the use of a contrast medium.
During the study, the patient will only feel a rumble from a working tomograph. Sometimes, so that the noise of the tomograph does not interfere, the patient is given headphones for listening to music. The diagnosis made allows you to immediately identify the presence of pathologies. Based on the results obtained, the diagnostician writes a conclusion with which the patient should consult a doctor.
It's important to know! Sometimes the MRI procedure is performed under general anesthesia, but not because it can cause pain, but to immobilize the patient. Under sedation, MRI is performed for children and patients who suffer from claustrophobia and other nervous disorders.
Is MRI with a contrast agent harmful?
To date, in medicine there are no absolutely safe contrast agents. Nevertheless, the gadolinium preparations used for MRI differ from iodine-containing substances in a lesser degree of toxicity. Serious anaphylactic reactions are extremely rare.
For people with normal kidney function, gadolinium-based amplifiers will not cause harm. In severe pathologies, there is a risk of developing nephrogenic systemic fibrosis. Is it possible to conduct MRI with contrast in such a situation, decide after evaluating the results of a blood test.
Contrast drug for MR diagnostics Omniscan
There are also a number of relative contraindications to the implementation of the procedure with amplification:
- hypersensitivity to the components of the drug (individual intolerance),
- burdened allergic history (bronchial asthma),
- severe liver failure,
- severe anemia
- pregnancy (examination with contrast is carried out in case of emergency if it is impossible to replace with other methods),
- early childhood (up to 1 month).
A beautiful picture, they emphasize at the Tomography center, remains without a qualified staff. In Belarus, MRI training is carried out, but in very limited amounts: you can’t take such courses, doctors come from all over the republic. They last a month, which, according to experts, is not enough for such a wide field of medicine. Therefore, doctors who are interested in improving their qualifications use all possible sources of information: from specialized scientific and medical sites and communities to industry exhibitions and conferences.
“Doctors, referring patients to MRI, often do not indicate the purpose of the study, which they must put before another doctor - an MRI diagnostic doctor. They write "MRI of the brain." And for what? What do they want to see? ” - says Emilia Mezina, head physician at the Tomography Center. According to her, the training of doctors should positively affect the situation, making the study valuable to the patient in terms of obtaining information, because this procedure is not cheap.
We thank the medical center “Tomography” for their help in preparing the material.
MRI with contrast: possible consequences
Adverse reactions to contrast with gadolinium drugs can be immediate (sensation of warmth, cold, pain at the injection site) and delayed (slight redness of the skin, nausea, vomiting).As a rule, unpleasant phenomena pass independently and do not require medical intervention.
After the introduction of contrast, slight nausea may occur.
If the patient has doubts about allergies, a test should be done before the procedure. If the result is positive, in coordination with the attending physician, premedication is performed using prednisone or methylprednisolone.
The consequences of MRI - what they are and how to avoid them
Each person suffers a large number of diseases of varying severity, which, of course, is terrible, because some of them can even pose a threat to life.
For this reason, it is necessary to start combating terrible ailments at the stage of their development, because in this case the chances of a successful cure are significantly increased, and a detailed and accurate diagnosis is necessary to start the early fight.
Despite the development of modern technologies, not so many methods are known that can be compared with MRI in their effectiveness, and they are not needed, since the negative consequences of MRI, according to experts, can only occur if contraindications are ignored. Let's take a look at magnetic resonance imaging and its effect on the body.
How to get an MRI?
An alarmed patient can also be recommended to take a sedative 30 minutes before the procedure (if he does not have to drive a car). Note that strong drugs that cause drowsiness should not be taken: the patient’s sleep during an MRI is an undesirable moment, especially in the process of examining the head. After all, falling asleep is sometimes accompanied by snoring or involuntary twitching of the muscles of the face.
It is worth remembering that even minor patient movements can lead to the appearance of motor artifacts that degrade image quality. In addition, when conducting an examination of the organs of the abdominal cavity and retroperitoneal space, it is necessary to follow the instructions of the operator (for example, hold your breath).
In some cases, the patient needs to be in the tunnel of the tomograph for a long time (about 40 minutes). The only inconvenience that the patient may suffer in connection with this is the need to stay in the tomograph in a stationary state. Often, patients fear that they will not be able to lie quietly for a long period, and any movement will entail the appearance of artifacts. Indeed, it is extremely important to maintain immobility during the study, therefore, in our opinion, the patient should psychologically prepare himself for MRI in advance.
Why is it important to do an MRI?
Usually, when people doubt the safety of something, they just try to avoid it, but this situation is much more complicated. The fact is that MRI of the brain, MRI of the spine and other options allow you to diagnose just a huge number of terrible diseases. Here is some of them:
- infections affecting bones and blood vessels,
- various inflammatory diseases
- pathologies associated with the brain or even the spinal cord,
- tumors (head MRI using contrast allows to detect both benign and malignant tumors),
- diseases of the cardiovascular system (it is necessary to do an MRI with contrast).
MRI is an absolutely safe and painless research method.
What happens to the body during the procedure?
As you can already understand, MRI with or without contrast is an incredibly important procedure, but you need to understand how it affects the body.
Immediately, we note that there is no evidence that the procedure is harmful to health, and many experts even claim that it does not affect the body at all, and we can’t even talk about the negative consequences after MRI.
Some inexperienced people are trying to justify their position related to the fact that MRI of the brain or MRI of the spine are unhealthy procedures, by the fact that the procedure involves exposure to the body of a magnetic field, the power of which is very high.
In fact, it does not pose any health hazard at all, since the magnet acts only on hydrogen atoms (water) and nothing more. Thus, the water molecules in the body line up clearly parallel to the magnetic field, and this can not even affect the brain.
During MRI, the patient is not exposed to ionizing radiation.
It is worth explaining the principle of the appearance of images: when a magnetic wave begins to act a little differently, the ordered atoms begin to make special oscillatory movements leading to the emission of energy. The image largely depends on the size of these vibrations.
As you can see from the above facts, both the magnetic field and the rays - all this does not pose any harm to the body. This also confirms the opinion that MRI of the brain or MRI of the spine can be repeated exactly as many times as the specialist considers necessary for a competent diagnosis.
Note! It is worth noting one feature of such a magnetic method. We are talking about a slight increase in tissue temperature, but this does not affect the body at all, therefore there are no harmful effects of MRI on health, if everything was done according to the rules.
How to prepare for an MRI?
Firstly, to stop being afraid of an MRI scan, the patient should learn as much as possible about this procedure. Having familiarized with the algorithm of the procedure and making sure the competence of the radiologist, the patient will feel more confident during the scan.
Secondly, the best way to overcome fear is to make sure that it is groundless. The day before the procedure, the patient can discuss their concerns with loved ones or write them on a piece of paper. For example, if the patient is afraid that his condition will worsen in the tomograph, but they will not be helped, it is obvious that the patient is worrying in vain, because such a situation is completely excluded. The study is followed by an MRI operator and a radiologist.
Thirdly, immediately before being in the scanner room, the patient can ask the doctor questions that concern him.
Over the years of the work of our center and the huge number of studies performed in our practice, there have been one or two cases when an X-ray lab technician was forced to interrupt an MRI scan. Taking into account that the expense of successfully completed procedures goes to tens of thousands, we should pay tribute to the professionalism of our specialists. They readily answer patients' questions and cheer those who need it. For maximum comfort, we also offer visitors to our center special headphones for muting the noise from the tomograph. It is important to note that in our MRI machine the tunnel is ventilated and illuminated (not every tomograph model has such options).
An MRI scan is an absolutely safe and painless type of radiation diagnosis. We emphasize once again that there is no objective reason to worry about conducting a survey. Fear of the procedure or during it is just a consequence of the unjustified excitement of patients. We recommend that visitors to our center trust real professionals.
We recommend that you also read the article "How to overcome the fear of MRI."
Types of devices and their effect on the body
Despite the conclusion made, it is worth considering the question regarding various types of devices for MRI of the brain or MRI of the spine. We are talking about the fact that there is a closed and open equipment.The closed type is a special pipe that is open on both sides.
As for the patient, he must get into this tube by “driving” the table into this tube. Pay attention to the fact that you have to lie there for 30-60 minutes, which, in fact, is quite a lot. Most likely, you will be given a special remote control, with which you can inform the doctor that you have become ill, then the procedure will be suspended.
As for the open type, in such tomographs the magnetic elements are located a little differently. They are in a unique C-shaped arc, with which the table is already moving.
A similar design was created for those people who suffer from claustrophobia, since the device will completely cover only a certain part of the body that needs to be examined.
It is worth noting that in such devices, magnets are slightly weaker, which does not allow taking pictures of the highest resolution.
Based on the presented material, conclusions can be drawn about less harm from open-type devices, but this assumption is incorrect, since we can not forget about the conclusions made earlier.
We are talking about the fact that in any case, the study will not present even the slightest danger to the body if you do not have metal objects with you, an allergy to contrast and kidney diseases.
It is also forbidden to do MRI of the brain and MRI of the spine for those people who have metal implants, since the problem will not only be in the blurry image, because such a procedure carries a rather serious health hazard.
It is worth mentioning that due to the harmlessness of both methods, experts prefer to prescribe a closed procedure, since the pictures in this case will turn out to be better.
MRI is performed from 15 minutes to 1 hour.
The presence of various kidney diseases
Kidney disease can result in nephrogenic systemic fibrosis as a result of exposure to a magnetic field. No, it cannot be argued that any disease that affects the kidneys will lead to a similar outcome, but the chances of ending the procedure will increase significantly.
For this reason, medical workers do not recommend going to the procedure with a similar diagnosis if the goal is not justified.
But, despite the rather low chances of an adverse outcome, systemic nephrogenic neurosis can cause symptoms such as tightening of the skin, a significant limitation on the flexibility of the limbs.
Renal failure is a contraindication for MRI.
The presence of metal objects
Specialists always warn patients that no items made of metal should be brought to the procedure. If you did this, then they must be removed before the process begins.
Otherwise, if you do not do this, most likely, it will end with serious damage to the skin at the sites of contact of objects. This rule is easy to follow, so there should not be a problem with this.
The presence of metal implants
If the patient has any implants, then it is necessary to immediately warn a specialist, because the same pacemakers may simply stop working during the procedure, which will definitely end sadly.
Metal structures can be severely damaged even if the implants do not touch vital organs. But such a point of view is far from always true. The fact is that some implants may not even have ferromagnetic properties, because of which there is a similar limitation.
Such situations may not be hazardous to health, but the image will still not be as accurate as in the situation with the absence of such prostheses.
The presence of metal implants in the patient’s body is an absolute contraindication for MRI.
Important! You can find out detailed information about each implant in his passport. Thus, you can know for sure whether the ferromagnetic elements are contained in a particular prosthesis.
Allergic reactions to contrast
For the reasons described earlier, the danger of the procedure in the absence of contrast ends. For this reason, we can conclude that all the consequences are directly related to the violation of the operating rules.
As for contrast, this substance is, one might say, a means of obtaining much more information. For example, only contrast will help to study the state of the vessels of the brain.
Unfortunately, some patients have allergic reactions to such substances. Here is a sample list of them:
- difficulty breathing
- urticaria and other manifestations.
It is worth noting that it is advisable to pre-do a test that will confirm the absence of an allergy to contrast, and only then start the procedure. If you have not done so, serious consequences may appear. Fortunately, there will definitely be staff at the hospital who will assist you.
An allergic reaction to a contrast medium is possible.
Comparison of the effects of MRI with the effects of other diagnostic methods
After the conclusions made about the safety of MRI, it is worth talking about other common diagnostic methods. We are talking about x-rays, as well as computed tomography.
As for the first option, the x-ray does not give such accuracy as the procedure under consideration, but it allows you to easily diagnose, for example, injuries associated with bones, without the difficulty and expense of time.
It is worth mentioning that X-rays are considered the most harmful of these three methods.
CT is the most affordable and cost-effective method, and the negative consequences from it are not as big as from X-rays, but they still exist, because the process uses the same X-rays. For this reason, many experts recommend doing an MRI scan!
Is MRI of the brain and spine harmful? Is it possible to do MRI for pregnant women and children?
In modern medicine, specialists often resort to the latest diagnostic methods, such as computed, magnetic resonance imaging. Specialists prescribe this procedure to patients of different age categories (children, elderly people). Accordingly, patients often wonder whether MRI is harmful to health.
Does the procedure affect the body
Magnetic resonance imaging is represented by a tomographic method for the diagnosis of tissues, internal organs in which nuclear magnetic resonance is used. The research method is based on:
- measuring the responses of electromagnetic waves from the nucleus of a hydrogen atom,
- the level of activity of the nuclei of hydrogen atoms with different combinations of electromagnetic waves in a constant magnetic field, as well as at high voltage.
Magnetic resonance imaging is prescribed to obtain the most accurate, reliable information about the state of such organs: the cardiovascular system, musculoskeletal system, and cerebral vessels. The diagnosis due to this diagnostic method is 97% true. MRI is able to detect pathologies, developmental abnormalities, the size of which is about 1 mm or more.
Patients are concerned about the possibility of any harm from MRI. They have heard that a variety of side effects can manifest themselves after several years. Some skeptics sowed doubt among patients, saying that this diagnostic method can cause irritability, headaches, apathy, fatigue, and cancer.
In fact, scanning of an organism is carried out by means of a magnetic field of very high frequency. Such an effect does not provoke any pathologies in the patient.
Negative consequences do not occur in a person after CT or after any period of time. This fact is reliable.
The evidence is the repeated tests that were conducted on animals, as well as many years of experience using this diagnostic method in examining people.
The basis of the procedure
The principle of operation of the apparatus that is used (magnetic resonance imager) is to synthesize a magnetic field, radio frequency pulses. So, as people have heard about the negative effects of magnetic storms, they are concerned about the question whether an MRI scanner has a similar effect.
How a patient usually undergoes magnetic resonance imaging. To complete the procedure, the patient lies on a table in a magnetic field. Scanning is performed using radio waves.
Molecule changes are transmitted to the computer. These changes can be detected due to the resonance of the nuclei of the atoms of the body inside the magnetic field.
After the received data will be processed by the computer, the doctors will be given the results in pictures, indicators.
Different tissues of the human body contain an unequal amount of hydrogen. With this in mind, the signals coming from different organs have significant differences. Thanks to this, diagnostics make it possible to obtain very accurate images.
The duration of the procedure is affected only by the area in which the study is necessary. MRI can take 20 minutes or an hour and a half.
Most often, the diagnostic method considered by us is used when examining the brain, spinal cord, and nervous system.
It is prescribed in cases where the specialist suspects the development of a tumor, cancer, some neoplasms.
Is the diagnosis of the brain and spine harmless?
Experts recommend an MRI of the brain if the patient has dizziness, a headache. Going to the procedure, patients are wondering - is MRI of the brain harmful? Now we find out.
The procedure is carried out inside the cabin of an MRI scanner, where a strong magnetic field is created. All information is supplied to the computer due to electromagnetic influences, which, as proved by experts, are absolutely harmless to the human body.
The only negative consequence may be an allergy due to a contrast agent. To avoid this consequence, you should make sure that the patient is not allergic to any of the components of the contrast medium. Only then can an MRI of the brain with a contrast agent be done.
We examined whether brain MRI is harmful or not. Now we indicate the conditions in which this procedure is contraindicated. In addition to pregnancy, claustrophobia, the presence of implants, MRI cannot be performed with:
- renal failure
- the presence of individual psychosomatic disorders.
Spinal MRI is required if you suspect:
- the presence of a tumor
- the presence of a vertebral hernia, protrusion of the intervertebral disc.
This procedure is considered safe due to the lack of information regarding the negative effects of the magnetic field. MRI can be performed as often as needed by the doctor in the treatment of a particular disease. There is no irradiation with MRI, because X-rays are not used to obtain images.
Is MRI allowed for children?
MRI is often prescribed for children. Naturally, parents are worried. They are interested in acquaintances, specialists - is MRI dangerous for children? This procedure is completely harmless to everyone. It is she who gives exhaustive information about the state of internal organs, the brain, and the musculoskeletal system.
When conducting an MRI scan for a child, his age-related features should be taken into account. To avoid fright in a closed chamber, with unfamiliar sounds of a working scanner, children need soothing drugs.Sedatives can be administered intramuscularly, given a drink, diluted in water.
If magnetic resonance imaging could harm a child or even an adult, experts would not prescribe it. So far, all doctors and physicists assure patients of the absolute safety of this procedure. And given its incredible information content, it has become simply a necessity in the early diagnosis of many dangerous diseases.
What happens in the patient’s body with an MRI scan?
MRI diagnostics is a safe way to study the condition of nerves, brain, circulatory system, ligaments, muscles, other tissues and organs of the human body.
Magnetic resonance imaging is currently used in almost all areas of medicine, often shows higher efficiency than other invasive and non-invasive techniques.
However, many patients are concerned about the purpose of this procedure.
A clear idea of how an MRI scan goes, what the patient feels, will help get rid of fear.
What the patient experiences with MRI
As a rule, magnetic resonance imaging is an absolutely painless procedure. However, a number of patients may experience some discomfort during its passage.
- Often, patients are concerned about an attack of claustrophobia as a result of prolonged exposure to a confined space. In some clinics, a similar problem is solved through the introduction of anesthesia.
- The feeling of light warmth is absolutely normal, it should not cause the patient anxiety.
- In most cases, during magnetic resonance imaging, the patient is left alone in the examination room. But the technologist still has the opportunity to talk with him, hear and see, this is done through two-way communication. In many clinics, when conducting an MRI, parents are allowed to stay in the room if the patient is a child.
- An MRI scanner during the shooting produces a fairly loud knock. Get rid of the unpleasant sensations associated with this will allow earplugs, which you can ask the clinic staff. For children, headphones or earplugs of the appropriate size are used.
- In the process of introducing a contrast medium (if the study implies a similar need), a person may feel a rush of blood, some coolness. Such sensations are absolutely normal, basically lasting no more than two minutes. A certain discomfort is caused by the introduction of a needle into the vein, as well as its removal, possibly even bruising.
- A number of patients feel a metallic taste in their mouths if, in the process of magnetic resonance imaging, injections of contrast medium were used.
Physics of the phenomenon
Magnetic resonance imaging works on the principle of magnetic resonance, the basis of which is the saturation of body cells with hydrogen molecules. Depending on the environment, they have different properties and, as a result, emit electromagnetic waves in different spectra.
The composition of the hydrogen nucleus, as is known from the course of chemistry and physics, includes a single proton with a certain spin (magnetic moment). It changes under the influence of artificial and strong natural fields, in particular magnetic, but with the condition that their frequency enters into resonance with the proton vibration frequency.
Using the fact that the proton spin has only two opposite phases (vector directions of motion), attached to the magnetic moment of an elementary particle, it is possible to accurately determine the location of a hydrogen atom with certain frequency characteristics using electromagnetic waves of a high magnetic field. This is about MRI technology. The principle of operation is as follows:
- the spin (magnetic moment) of a proton placed in an external magnetic field is directed to the same (as the field) or opposite side (in this case, its energy potential will be much higher than in the first case), there is no third
- under the action of radiation, the proton inverts its magnetic moment, and after the termination of the external stimulus, it instantly returns it back,
- sensors record a burst of energy during relaxation of an excited elementary particle,
- software on the basis of incoming data analyzes them and builds an image.
The magnet used must be very strong. If the first devices were equipped with magnets with an induction of only 0.0005 T, giving a very low-quality and blurry low-resolution image, then modern tomographs use magnets of 1-3, and in some cases up to 9 T. Often operated elements with the effect of superconductivity, which manifests itself at low temperatures. Usually they work immersed in liquid helium.
The response to permanent magnets is much weaker than electromagnets, but the former have a clear advantage - they allow:
- carry out MRI examinations in motion, standing or sitting,
- provide access to the patient to the doctor or radiologist.
For examination of the spine and brain, low-floor devices with a field strength below 1 T are used.
To obtain accurate information about the localization of the hydrogen atom whose proton emits, the permanent magnet or electromagnet is often replaced by gradient coils. They add magnetic disturbance in the form of a gradient to a uniform field. Thanks to it, high accuracy of data acquisition is provided. It is the speed and power of the gradient that are one of the key characteristics of the tomograph. The resolution of the device and the quality of the signal (the amount of noise) depend on them.
Principle of operation and advantages over other diagnostic methods
The principle of operation of an MRI scanner is based on the characteristics of the magnetic field and the magnetic properties of body tissues. Due to the interaction of nuclear magnetic resonance and the nuclei of hydrogen atoms, a layered image of the organs of the human body is displayed on the computer screen during the examination. Thus, it is possible not only to differentiate some organs and tissues from others, but also to fix the presence of even minor disorders, tumor and inflammatory processes.
The principle of MRI allows you to accurately assess the condition of soft tissues, cartilage, brain, organs, spinal discs, ligaments - those structures that are largely composed of fluid. At the same time, MRI in medicine is less used if it is necessary to study bones or tissues of the lungs, intestines, stomach - structures with a minimum water content.
Closed-type tomography apparatus
Due to the way MRI works, a number of advantages of this type of research can be distinguished over others:
- As a result of the inspection, a detailed image can be obtained. Therefore, this technique is considered the most effective for the early detection of tumors and foci of inflammation, the study of disorders of the central nervous system, musculoskeletal system, abdominal and pelvic organs, brain, spine, joints, blood vessels.
- Magnetic tomography allows you to diagnose in those places where CT is not effective due to the overlap of the examined area with bone tissue or due to the insensitivity of CT to changes in tissue density.
- During the procedure, ionizing radiation of the patient does not occur.
- You can get not only an image of the structure of tissues, but also MRI readings of their functioning. For example, blood flow velocity, cerebrospinal fluid flow, and brain activity are recorded using functional magnetic resonance imaging.
- Possibility of performing contrast MRI. Contrast enhances the diagnostic potential of the procedure.
- Open-type MRIs allow examinations to patients with fear of confined space.
Another advantage - when making a diagnosis, errors are practically excluded. If the patient is concerned about the question: “Can MRI be wrong?”, The answer is a bit ambiguous. On the one hand, this procedure is one of the most accurate diagnostic methods. On the other hand, errors can occur at the stage of decoding the results and making a diagnosis by a doctor.
Before and after
Before you learn how to conduct an MRI scan, let's pay attention to the preparatory stage: what you should know and consider if you have a procedure assigned.
The magnetic field of the tomograph is about 4 orders of magnitude higher than the intensity of the natural earth's field. Doctors studied the influence of the process and proved that short-term exposure does not affect the physical condition of a person, at least no noticeable harm was found.
The effect of such powerful irradiation on the structure of atoms and molecules is not considered.
Despite this, the MRI technique requires the implementation of a whole set of rules, recommendations and safety requirements. All should be brought to the attention of the patient.
- We fill out the proposed questionnaire, where we indicate the state of health, the last surgery and illnesses, so that the doctor can identify contraindications, if any.
- After appearing in a booth or other changing room, we remove all metal objects (chains, earrings and other jewelry), clothes with such elements: a shirt with metal buttons, a belt, a sweater with a zipper. We remove from the pockets all metal-containing objects (keys, money) and working using a magnetic field (telephones and other gadgets, magnetic digital media, credit and other cards, headphones).
Before the procedure, make sure that your cosmetics do not contain metal molecules whose presence will distort the magnetic hollow and, as a result, the overall picture of the study.
- During a clinical study, it is imperative to protect the hearing organs from mechanical vibrations (the device is very noisy) using special headphones.
- Before you go to bed, you should definitely learn such things: what are the advantages of the procedure and how will it help to treat or detect an ailment, how will the MRI scan be done, do you have any individual contraindications for it, is the contrast used, if so then for what purpose.
- There are no restrictions on the intake of food and drink, except for the intake of psychotropic and narcotic substances, including alcohol.
- When conducting an examination with contrast, the doctor may recommend eating nothing for 3-4 hours before visiting the tomograph.
If you are distinguished by the presence of fear of small and enclosed spaces, be sure to notify the doctor. Perhaps he decides to introduce a sedative before the procedure.
What contraindications are taken into account when an MRI is performed
Contraindications for the procedure:
Before the MRI procedure, you must remove all clothing and jewelry that contains metal, put on a disposable gown, or other things without metal objects
- body tattoos containing metal elements in the dye,
- artificial devices that improve the functioning of internal organs: implants of cardiac activity, blood vessels, hearing aids,
- intrauterine devices, cosmetic devices implanted in the body,
- early pregnancy
- recent heart, brain, or blood vessel surgery,
- nervous diseases, epilepsy,
- patient weight over 120 kg,
- the presence in the body, and especially in the eyes, of metal pieces that have entered the body as a result of trauma.
All such cases should be reported to the doctor in order to avoid the harmful effects of high power magnetic field organs:
- burn at the place of tattooing,
- corneal damage
- failure of the implants
- the effect of a magnetic field on the fetus is not fully understood.
If a person suffers from renal or hepatic insufficiency, it is necessary to pass a biochemical analysis of blood and urine so that the doctor can fully assess the condition of the patient's internal organs in case of the introduction of a coloring matter. An allergy test is also performed.
How do MRI with axial load: after horizontal tomography of the spine, the table with the patient and the magnet rises to a vertical position
When can not be manipulated
Despite the complete safety and accuracy of the data obtained, MRI of the whole body has contraindications. These include:
- the presence of any magnetic devices built into the body, for example, a pacemaker,
- any metal fixed prostheses,
- metal-based artificial valve,
- the remaining metal fragments, for example, from shells.
Built-in devices for supplying the body with insulin, as well as the reluctance to part with any metal object, make MRI impossible. A relative contraindication is claustrophobia. The patient will be in a completely closed space for 60 minutes. If claustrophobia is pronounced, then the patient is sedated.
For the passage of MRI, there is a whole list of reasons:
- diseases and abnormalities in the development of head vessels,
- brain injuries that occur with hemorrhage in the cranial cavity,
- CNS tumors
- pituitary disease
- brain infectious disease
- aneurysm, thrombosis and other abnormalities,
- a tumor of the so-called cerebellar cerebellar node,
- multiple sclerosis,
- constant pain, the cause of which needs to be studied by specialists.
None of the cases should categorically be spent visiting a special clinic: the disease / virus will only progress, and time is not in your favor.
For minors, MRI is prescribed in a much smaller number of cases, despite the absence of harm from the process itself:
- periodic or frequent fainting for no apparent reason,
- developmental lag behind peers,
- logoneurosis (significant delays in the appearance of the child's speech),
- serious reasons to believe that there are mental disorders or abnormalities,
- convulsive seizures.
Once again, we note that no negative influence was found by specialists, but this does not mean that it is absent.
What disorders in the body can a procedure detect
The body scan captures all tissues, from the brain to the proximal femur. In this case, it is possible to diagnose a minor pathology that does not affect the quality of life and is an accidental find. Such pathological changes are not given importance, since the main attention during the procedure is given to life-threatening conditions.
When conducting a full MRI scan of the whole body, the following structural changes are revealed:
- foci of myeloma in the brain,
- any violations of the bone structure of the skull,
- aneurysmal dilation of blood vessels of any location,
- the presence of infiltration in the lungs,
- any structural abnormalities of the lung tissue or bronchi,
- volumetric formations, including small ones, of any localization,
- the presence of plus tissue in the cavities of the heart or on the valves,
- structural features of the liver and pancreas,
- stone formation process in any field,
- the presence of purulent-inflammatory foci in any organ.
Pay attention to any extraneous volumetric formations. They can be either of a dense structure, for example, a tumor, or liquid, for example, cysts or purulent contents.
Now we will consider how MRI is performed, what it consists of, what happens and what gives. Let's start with the last one.
The examination reveals tumors, aneurysms, problems with the vessels of the head and the nervous system in general, with its help the activity of the cortex is monitored. There are two modes of MRI: without contrast and using substances that increase the contrast of the desired tissue. In this case, gadolinium salts are usually added. The advantage is high accuracy, for which you can pay for the occurrence of an allergic reaction to the substance. The specialist must identify her appearance in advance.
An MRI machine looks like a large hollow cylinder. The subject is located on a moving table, which enters the apparatus. Before the examination, the patient is rather tightly fixed with straps so that his movements are minimal. The fewer they are, the sharper the image will be, and the data and conclusions based on their analysis will be accurate.
Around the head are emitters with conductors, which will generate the necessary magnetic field. Often, but not always, it is suggested to wear headphones or ear plugs to protect your ears from noise arising during the operation of the device. After the final preparation, the table is moved to the apparatus, and the X-ray laboratory technician and / or doctor are sent to the computer, through which the magnetic resonance imager is controlled.
The system creates a sequence of images giving a complete picture. The creation of each tomogram takes several (2-5) minutes, as for the examination of the head, when scanning the abdominal cavity, the process is delayed by half: without applying contrast, the procedure will last 15-30 minutes, with the substance that creates the contrast, about two times longer - 25 -50 minutes.
Radiation does not cause discomfort, except that it is necessary to lie still all the time. Each movement or change in body position negatively affects the quality of the image.
At each pass, 4-5 mm tissue is scanned, and the process continues until a complete picture is obtained, which can drag on for two dozen cycles. In devices with a higher magnetic field strength, these slices will be thinner, and the result is more accurate, although the process will take a little longer. Modern devices with a powerful magnetic field allow you to examine any part of the brain, and not the entire organ.
Sometimes the patient is injected with a substance that will give the pictures a contrast. Usually it is a compound harmless to the human body, but can cause an allergic reaction. In order to verify its absence or presence, a small dose is initially introduced and observation is carried out. If everything is in order, the contrast is administered in the right amount for a certain period of time before the study.
How is the survey
An MRI device is a large hollow cylinder into which a patient is placed while lying down. The whole procedure lasts from 30 minutes to a couple of hours and depends on the complexity of a particular case. In this case, no harmful effect on the body is not. The only inconvenience is being in a confined space, which is beyond the power of persons suffering from claustrophobia. There is an open MRI device, but, unfortunately, not every medical institution is equipped with it.
How do MRI scans:
- the patient is in a supine position on a retractable instrument table,
- the correct diagnostic result is possible only while maintaining immobility during the examination, this is especially true when scanning the spine. Even a slight change in posture leads to blurry images on the monitor.The arms and legs of a person are fixed with soft straps, special rollers. Young children are diagnosed with MRI under general anesthesia. If a person is nervous, a sedative can be taken orally or intravenously,
Hands or feet of a person are fixed with soft straps, special rollers
Getting the result
About half an hour after the completion of the procedure (depending on the workload of specialists), you can get a conclusion. It is printed on paper, sent by e-mail or recorded on any digital storage medium together with an application for viewing and printing the results. Typically, the role of the media is a CD. Here you can also get advice, which, as a rule, is paid separately.
The following conclusions are considered normal:
- neoplasms not found
- pathologies in the soft tissues are absent,
- blood clots, pathologies and hemorrhages not found,
- dimensions of the ventricles are normal.
Conclusions that may be a concern:
- a tumor, swelling, or tumor is detected,
- traces of the development of an infection or an inflammatory process are found,
- bleeding, abnormalities in the development of blood vessels or aneurysms are noted.
What the study shows
The difficulty in diagnosing the spine lies in the proximity of the soft tissues and vertebrae. Ordinary species, such as ultrasound, X-ray, CT, cannot give a complete picture of the state of health, especially at the initial stage of the disease, therefore more sensitive equipment is used to establish what is needed for treatment.
MRI of the spine
Benefits of Magnetic Resonance Imaging in relation to nerve tissue:
- better visualizes lesions of the nerve structures of the brain and spinal cord,
- allows to determine inflammatory and tumor formations at the level of histological examination,
- creates a three-dimensional image of the affected area,
- makes it possible to see the smallest tumor formations or metastases using a contrast medium.
Because MRI gives layered pictures, at the same time you can see the location of the bone tissue of the spine in relation to the soft tissues - infringement, compression changes. The contrast agent allows you to visualize the exact location of the tumor before surgery. Surgical fusion of the vertebrae with osteochondrosis, stenosis, and fractures cannot be treated without a preliminary assessment of the condition of the bone tissue based on the conclusion of a radiologist.
This completes the description of the MRI procedure. It remains only to highlight its advantages over other examination methods and features:
- it is possible to identify abnormalities in the work and development of the brain that cannot be detected in other ways,
- safety of administration of a contrast medium - the probability of a reaction is minimal, and it is always taken into account,
- identification of complex pathologies in the initial stages of their appearance,
- easily detected formations in the soft tissues of the brain and tumors in the first stages of their formation,
- safety has been proven by scientific research, although the changes introduced by a strong magnetic field into the structure of irradiated tissues have not been studied, and what they can turn into is simply unknown to science.
- the absence of radiation harmful to living cells: x-ray or ionizing,
- the patient is affected only by a high magnetic field, and for a short time,
- you can see the brain tissue in a transverse and longitudinal section,
- the ability to study the state of the vessels of the brain,
- determination of the real place of occurrence of pathologies, their exact shape and size in all planes.
How to dress for magnetic tomography
Magnetic tomography is performed more often to confirm the diagnosis, after a comprehensive study of the body by other methods.
Before the MRI procedure, it is necessary to remove all items of clothing and jewelry that contain metal. You should dress in a disposable bathrobe, or other things without metal rivets, hooks, buttons and the like.
It is necessary to warn the doctor in advance about the existing dentures, dental fillings, implants with metal components that can change the magnetic field of a person, distort the diagnostic results.
What is contrast MRI?
In some cases, MRI requires the use of contrast - a special substance that can improve the visibility of small foci of the disease and individual sections of the study area.
The image shows how the contrast is clearly visible in the MRI images of the arteries of the brain.
The amount of contrast medium is calculated individually for each patient, after which it is administered intravenously into the body. Through blood, contrast gets into the tissues changed by the disease, due to which the clarity of the image becomes higher, which in turn allows to increase the accuracy of diagnosis.
More details about the features of MRI using contrast can be found in this article.
In order to make the results of the examination even more accurate, sometimes special contrast agents are used for MRI. Gadolinium is mainly used for magnetic tomography - a drug that allows you to make body cells even more sensitive to the effects of magnetic waves.
To conduct a diagnostic examination using contrast agents, a catheter is inserted into the vein before the procedure, to which a system with a special physiological saline is attached. First, a very small dose of gadolinium is used in order to see how the body will respond to the contrast agent.
Such a study will have a number of differences compared with a conventional magnetic resonance examination. For example, a contrast medium will allow you to get a much clearer picture of the necessary part of the brain, to conduct a more accurate diagnosis, but MRI with contrast will take 15 minutes longer than the procedure without using the substance.
Indications for MRI are completely based on its diagnostic features, namely the number of hydrogen molecules in the tissues. So, in almost all soft and cartilage formations, thanks to the procedure, the following types of pathological processes can be diagnosed:
In addition, after an MRI is done, it becomes possible to track changes in the vascular beds of the circulatory system, as well as the lymph and its nodes. Diagnosis of the spine with this method allows you to recreate the full (three-dimensional) image of all the structures that form it, and analyze the activity of the musculoskeletal, nervous and circulatory systems.
Brain MRI allows you to get a 3D model of an organ
This diagnostic feature sometimes makes patients who are prescribed for the procedure wonder why spinal MRI is done if the bone tissue is not well visualized during the examination? The recommendation for passage is justified by the fact that pathologies of the spine often lead to the appearance of diseases of the surrounding tissues, for example, the same osteochondrosis, which causes nerve infringement.
Features of the study and patient sensations
It is worth noting that most patients who underwent tomography note such a drawback as loud noise. If sharp sounds cause discomfort or uncontrolled fear, panic, the patient is recommended to use noise-isolating headphones.
As for the procedure, which is carried out using a contrast medium, it is characterized by a longer duration and preliminary intravenous administration of the drug.
Before a gadolinium-based drug enters the bloodstream, it is necessary to test the drug in order to avoid the sudden development of an allergic reaction.
A substance is used to improve the visualization of malignant neoplasms, the state of the vascular system. A “standard” MRI scan lasts about 20 minutes; if necessary, contrast can be increased by as many minutes.
After the screening, the patient will not have to linger, to restore strength.
After deciphering the results, the patient can go to his doctor to prescribe or correct treatment based on the conclusion of the diagnostician.
Often, the specialist is able to establish the disease only with a comprehensive examination, which is the reason for the passage of additional research procedures and consultations of narrow-profile doctors.
Do I need to prepare for the procedure?
Diagnostics by an electromagnetic field does not need a preparatory process. There is no need to adhere to a certain diet and follow a diet. Only if necessary, to examine the pelvic organs, you need to come to the procedure with a filled bladder - since it diagnoses MRI in this area with the walls of the organ straightened.
There is another point to consider when prescribing MRI with contrast enhancement. Even provided that non-allergic drugs based on gadolinium salts (Omniscan, Gadovist) are used for contrasting, you still need to test first. The individual intolerance of each individual patient cannot be ruled out.
Before you go to the procedure, it is best to think over clothes and choose the one that does not contain metal objects - zippers, buttons, rhinestones and other jewelry. Some private clinics offer to change into a medical shirt, specially designed for such events. You should not come to MRI in underwear with Lurex, as his thread was created with an admixture of iron.
Immediately before the diagnosis, you need to remove all jewelry, watches, glasses, removable dentures and the ear device.
An important point that should not be ignored is a visit to the office with all the previous, if any, survey results. This will allow the doctor to immediately compare new images and conclude that the treatment is effective or the rate of progression of the disease, or its remission.
The essence of the method
Computed tomography (CT) is based on the ability of tissues of the human body, with varying degrees of intensity, to absorb ionizing radiation. It is known that this property is the basis of classical radiology. With a constant strength of the x-ray beam, tissues having a higher density will absorb most of them, and tissues having a lower density, respectively, lower.
It is not difficult to register the initial and final power of an x-ray beam that has passed through the body, but it should be borne in mind that the human body is an inhomogeneous object that has objects of different densities along the entire path of the beam. When x-ray, to determine the difference between the scanned media, it is possible only by the intensity of the superimposed shadows on the photo paper.
The use of CT allows you to completely avoid the effect of overlapping projections of various organs on each other. Scanning with CT is carried out using one or more beams of ionizing rays transmitted through the human body and recorded from the opposite side by the detector. The indicator determining the quality of the received image is the number of detectors.
In this case, the radiation source and detectors synchronously move in opposite directions around the patient's body and register from 1.5 to 6 million signals, allowing you to get a multiple projection of the same point and the surrounding tissues. In other words, the x-ray tube goes around the object of study, stopping every 3 ° and doing a longitudinal displacement, the detectors record information about the degree of attenuation of radiation in each position of the tube, and the computer reconstructs the degree of absorption and distribution of points in space.
The use of complex algorithms for computer processing the scan results allows you to get a picture with the image of tissues differentiated by density, with the exact definition of the borders, the organs themselves and the affected areas in the form of a section.
Important! Due to the relatively large amount of radiation received during CT, the study is prescribed, in cases of insufficient informativeness of non-radiation diagnostic methods.
How much is
Patients suffering from back pain of unknown etymology often go to the doctors to find out where to do an MRI of the lumbosacral spine. In Moscow, an inexpensive and high-quality MRI procedure can be done in specialized clinics. The cost of MRI of the spine ranges from 1800 to 17 000 rubles. The price of services depends on the back area and the need for the introduction of contrast agents, and sometimes on the time of day of the diagnosis.
Turning to the services of specialists offering a cheaper option for the diagnosis of the spine using MRI, one should check the availability of a doctor’s certificate, an institution’s license to provide medical services and a valid license for equipment used for examinations. Often low prices hide the lack of quality, which is unacceptable in health matters.
In medicine, it is customary to distinguish diagnostic methods in accordance with the anatomical regions of a person. Specialization helps to improve the accuracy of the examination. Computed tomogram is the result of one of the modern methods of studying diseases. Consider the types of examination:
- brain tomography - determines changes in blood vessels and membranes, bones of the skull, examines the structure,
- CT scan of the abdominal cavity - gives an assessment of the state of the digestive tract, congenital pathologies, cysts, tumors,
- tomogram of the lungs - studies changes in lung tissue, blood vessels.
No less informative is a computer examination of the anatomical areas:
- kidney tomography - shows a picture of the state of the organ, the presence of stones, fluid,
- CT of the chest - assesses injuries, infectious diseases, pleural effusion,
- spinal tomogram - shows intervertebral hernias, abscesses, pathologies of the spinal canal,
- CT of the sinuses of the nose - is prescribed for severe injuries, before plastic surgery,
- tomography of the heart - shows how the coronary arteries, heart muscles look.
For visual determination of tissue density during computed tomography, a black and white Hounsfield scale is used, which has 4096 units of change in radiation intensity. The reference point in the scale is an indicator reflecting the density of water - 0 НU. Indicators reflecting less dense values, for example, air and adipose tissue, are below zero in the range from 0 to -1024, and more dense (soft tissues, bones) are above zero, in the range from 0 to 3071.
Changing image contrast to improve visualization of structural abnormalities in the intervertebral disc
However, a modern computer monitor is not able to reflect so many shades of gray. In this regard, to reflect the desired range, a software recalculation of the received data is applied to the scale interval available for display.
In conventional scanning, tomography shows an image of all structures that differ significantly in density, but structures with similar parameters are not visualized on the monitor, narrowing the “window” (range) of the image. At the same time, all objects in the viewing area are clearly distinguishable, but the surrounding structures can no longer be seen.
In an MRI machine
As the study progresses, the knock and other sounds of the tomograph will change, but at the same time remain quite intense and loud. Headphones or ear plugs will muffle the sound a bit, but will not be able to completely eliminate it.
Most patients do not feel any discomfort inside the MRI device.
Before the procedure, many patients are interested in whether it is scary inside the device and can it hurt?
The sensations while being in the tomograph are purely individual. Even experienced patients who have been diagnosed more than once may experience anxiety and anxiety, while others, on the contrary, do not feel any discomfort.
Some especially sensitive patients may experience the following effects due to stress caused by limited space and noise:
- hot flashes or cold,
It is worth saying that this is a rather rare reaction to the diagnosis, but in case of its occurrence, you need to try to relax and breathe deeper. So the unpleasant state will pass faster.
Preparation for MRI of the spine
The procedure is absolutely safe and does not require changes in the usual mode of the day. It is not required to stop diets, taking medications for MRI of the spine. How the procedure goes - the attending physician will tell.
The patient is warned that you cannot move during the examinationthat the device makes loud noises all the time, but you should not be afraid of this, since people do not experience any special sensations.
Many are interested Is it possible to eat before an MRI the spine. Here a lot depends on what they will investigate. If bone tissue - then it is possible.
If cerebrospinal fluid - then the doctor will advise you not to overeat, since the state of the fluid depends on what kind of food the patient took.
If it is a heavy fatty food, then the readings of the device will record this in terms of speed and consistency. Refusal of food and water is required mainly for an examination of the abdominal organs.
Important! Patients with mental disorders, anxious, need additional administration of sedatives, which will provide immobility.
What does the doctor need to know before going through the procedure?
Patients are informed at any diagnostic center about how an MRI scan works and how to properly prepare for the study.
As already mentioned, the passage of the tomograph is prescribed by the attending physician, who gives the patient a direction for the resonance scanning method.
In modern clinics, one of the conditions necessary for the diagnosis is to fill out a questionnaire. In it, the patient must indicate all the required data.
Otherwise, silence can lead to distortion of the tomography results and other negative consequences.
Of fundamental importance are:
- the presence in the body of the studied metal prostheses, implants or electrical implants,
- it is necessary to indicate a tendency to allergic reactions, if any,
- the presence of confirmed chronic diseases.
To undergo an MRI, the patient will have to go to a specially equipped room where a huge device is installed. Usually, before the start of the study session, in some cases, the patient may be asked to change into hospital clothes.
An equally important stage in the preparation for the procedure is the maximum release of things and the body from any metal element with magnetism. If the patient finds it difficult to answer about the presence or absence of metal objects in his body, doctors consider passing a test on a metal detector an appropriate solution.
The feasibility of an MRI scan of the brain
Under what pathologies, when it is necessary and why MRI is prescribed without fail. Research should be urgently done if at least one of the signs of the following pathologies is evident:
- suspected swelling, cerebral edema,
- in the presence of hematomas of the head, spinal column,
- if there is a stroke attack,
- after accidents, bruises revealed swelling of the tissues of the head, neck,
- with osteochondrosis, scoliosis, atherosclerosis, there is a violation of blood circulation,
- with a convulsive symptom as a sign of epilepsy,
- if aneurysm is suspected,
- with accumulation of fluid in the brain tissue.
After the procedure, the doctor receives a series of 3D images that visually accurately reflect the vascular, tissue and bone changes in the head and neck.
How to behave during a scan
Between the scan, the patient will be able to relax, but his body position should remain unchanged, it is advisable to try to avoid the slightest movements.
As a rule, MR scanners are beautifully lit and ventilated. Certain devices have the ability to turn on music, this allows the patient to pass the time. You can use these functions at the prompt of a specialist.
What does the patient feel after MRI
If anesthesia was not used in the process of magnetic resonance imaging, a rehabilitation period is not provided. An immediate return to normal life immediately after the procedure is possible.
A number of patients can survive side effects associated with contrast agents, for example, local pains, bouts of nausea. If the patient is allergic to the components of the contrast medium, itching and hives and other reactions may also occur.
Be sure to inform the technologist about the occurrence of allergic symptoms, assistance will be immediately rendered.
Motov Mikhail Mikhailovich
Is MRI harmful to human health - effects on the body, effects and benefits
Is MRI harmful, and how does the electromagnetic field generated by the device affect the human body? Can a child or pregnant woman be exposed to the procedure? What will happen if a diagnosis is made with contrast enhancement? All these questions arise in many people who receive a referral to a rather expensive diagnostic MRI procedure. Let's try to answer them in this article.
Is an MRI scan harmful to the body?
The technique of studying the human body using MRI is not used in medicine for long - about twenty years. Most patients vaguely imagine the principle of operation and device structure.
For this reason, when receiving a referral for examination of the spine, knee joint, or, for example, the brain, the patient fears whether the scan will cause harm to 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 for 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 action 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 device. A “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 corresponding direction. Then, when high-frequency oscillations are turned on, they are excited.
The signals from the latter are captured by sensors and transmitted to a computer for decryption and imaging, which shows the state of the tissue or organ under study.
That is, there are no fundamental changes in the human body during the procedure.
The reorientation and excitation of hydrogen atoms are absolutely imperceptible phenomena, they do not affect either the well-being or the health of the patient. It can be concluded that the study is not harmful.
Electromagnetic wave irradiation
For example, the danger of the development of pathological changes arises with a daily prolonged (8-9 hour) exposure to an industrial (not even medical) source of electromagnetic radiation for 2-3 consecutive years, without interruptions. It is almost impossible to get such a dose of radiation by undergoing short MRI procedures, so there is no reason to fear for your health.
How often can you do an MRI of the spine and joints?
How often is it permissible to be scanned using EMF? An MRI examination of the spine and joints (including the knee) can be performed an unlimited number of times, provided that the person has no absolute contraindications to the procedure.
During the scan, the patient is not exposed to x-rays, therefore, long breaks between MRI are not required.
The procedure can be performed as many times as you like, even within one day - this does not harm your health.
For example, in the detection and treatment of 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 examining 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 so far no cases have been identified where the scan led to the development of intrauterine anomalies.
However, due to the fact that in the first 12 weeks the fetus is especially vulnerable, it is recommended that the examination be postponed until delivery or at a later date.
Does magnetic resonance imaging harm a child’s health? By itself, electromagnetic radiation, in the quantities that are produced by the tomograph, is not dangerous even for the smallest patients. When examining babies, another problem arises - a child cannot lie still in a narrow tube of a tomograph for 30-40 minutes.
To carry out a full-fledged procedure and get a reliable result, scanning has to be carried out under general anesthesia. The latter harms the cardiovascular and nervous system of a small patient. For this reason, abuse of MRI is not recommended - it can be harmful.
Consequences of using contrast agents
If there is a suspicion of the presence of tumors or the need to diagnose the state of the vessels, MRI with contrast enhancement is indicated. Can one expect various unpleasant surprises after such a procedure?
Gadolinium-based preparations are often used as contrasting agents. In rare cases, they are ways to cause an allergic reaction in a patient.
According to statistics, 0.01% of patients who undergo an MRI procedure suffer from hypersensitivity to gadolinium. Despite such minor indicators, allergy tests will be done before diagnosis with contrast.
If there is no allergy, then the likelihood of unpleasant consequences due to MRI is close to zero.
When is contrasting harmful? It can provoke a deterioration in the patient’s health and relapse of chronic MRI diseases with contrast if the subject suffers from kidney failure or cirrhosis of the liver. These conditions are among the contraindications to tomography. During the bearing of a child, a procedure with contrast enhancement is done only in emergency cases.
Contraindications to MRI
An MRI scan, 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 oscillations, is considered one of the safest methods. However, there are a number of contraindications to the procedure. They are divided into absolute and relative.
Among the relative prohibitions is the first trimester of pregnancy. The harmfulness of MRI for the fetus in the early stages of development has not yet been proven, but it is recommended to postpone the study "just in case".
- scanning with contrast is prohibited for patients suffering from hypersensitivity to gadolinium or impaired renal excretory function,
- decompensated diseases,
- mental disorders that are not even amenable to temporary correction,
- claustrophobia (the patient can be examined only in an open type apparatus),
- embedded 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:
- minimum list of contraindications
- lack of restrictions on the frequency of sessions,
- the ability to track the dynamics of changes in the state of the body,
- it is acceptable to use in the diagnosis of diseases in children from birth,
- low probability of side effects
- especially effective in visualizing the structures of the spinal cord and brain, other nerve tissues.
Is it harmful to health to do an MRI of the brain
The harm of magnetic resonance imaging is associated with the influence of a magnetic field. Obtaining slices of high sensitivity is possible due to the resonance of hydrogen atoms under the influence of a strong magnetic field.
Practical examinations show that water is part of 90% of tissues. After exposure to a magnetic field, protons are activated. The effect persists for the duration of the procedure. After the cessation of magnetization, the structure of the liquid molecules is restored.
Answering readers whether MRI of the head is harmful, we note the absence of negative consequences in practice. Medical discussions regarding the likelihood of a strong magnetic field affecting the genetic apparatus continue years after the procedure.
When MRI of the head and brain are prescribed, doctors first identify contraindications and indications.
X-rays are more dangerous. Rays damage the genetic apparatus, lead to chromosomal abnormalities. The action of high doses of x-rays causes acute radiation sickness. Magnetic resonance imaging eliminates genetic defects.
To determine whether it is harmful to do an MRI of the brain to a specific person, a radiology doctor can after a preliminary analysis of an outpatient card, the results of diagnostic methods.
There are no other symptoms. The use of MRI tomography repeatedly excludes theoretical distant changes in the genetic apparatus.Scientific research is ongoing, medical discussions regarding the negative effects are ongoing, but there is a rapid expansion of MR scans in private clinics.
Are there any harmful effects from MRI
Contraindications to the procedure exist. Any metal objects inside the human body under the influence of magnetization come into motion. Moving the pin, screw leads to damage to soft tissues.
Answering whether it is harmful to do an MRI of the brain, you need to focus on the individual characteristics of health. The danger of allergic reactions occurs after contrasting. The introduction of the paramagnet gadolinium intravenously improves the visibility of blood vessels, can provoke hypersensitivity.
Potential damage to brain MRI is free below computed tomography. After using the contrast, small-scale hemorrhages rarely occur, and the permeability of the arteries increases. The effects are associated with poor quality contrast agents.
An allergy is formed on the ballast compounds that make up the drug.
Verification of dangerous diseases of the head is much more important than theoretical complications (allergies, vascular changes).
What the brain MRI shows:
- Skull fractures,
- Intracerebral hematomas,
- Sheath hemorrhage,
- Neoplasms (malignant, benign).
Complications of a non-contrast head scan are rare. The alleged harm of the procedure with the exclusion of cancer, the tumor is less important than the verification of malignant neoplasms.
The truth about the dangers of magnetic resonance imaging
The minimal harmful effects of MRI on health are being actively discussed by critics of the survey.
There are versions regarding a significant change in DNA molecules, damage to the course of intracellular chemical reactions. There is no evidence of harm from the scientific research procedure.
Some authors describe an increase in heart rate, headaches in people after MRI. Sometimes the back of the head hurts, muscle tremors appear.
Magnetic resonance imaging of the spinal column, brain has indications, contraindications. If you comply with the requirements of a doctor, properly conduct preliminary diagnostics, minimizes the harmful effects of MRI.
It is impossible to unequivocally state that a certain diagnostic method is harmless. An individual assessment of the benefit / harm ratio by a specialist allows you to get the maximum diagnostic information with minimizing the consequences.
High-frequency magnetic fields cause dizziness in people with sensitive vessels. It is better to do an MRI scan for people with neurological diseases and mental disorders after taking sedatives.
Harm from magnetic radiation
It is possible to say that MRI is not harmful, after eliminating the presence of metal prostheses, implants, metal alloys, vascular stents, pacemakers.
If after an MRI it became bad, the back of the head hurts, it is necessary to exclude damage to the capillaries, arteries. Standard 1.5 Tesla tomographs cause a slight heating of soft tissues. Devices with power from 3 Tesla provide high resolution images, but the likelihood of complications increases.
What are the effects of MRI
Describing the effects of contrast injection, it is required to indicate not only allergies. Improper manipulation causes dangerous complications:
- Blockage of the vessel by air (embolism),
- Infectious infection - shock, sepsis, phlebitis,
- Local inflammation with the introduction of gadolinium drugs past the veins.
Magnetic resonance imaging of the brain with a contrast agent verifies small tumors, establishes the size of the neoplasms. It is unimportant how harmful MRI is in this situation, since the risk of an undiagnosed tumor at an early stage is more dangerous than small complications.
With head MRI, the dose of radiation is not calculated. The absence of ionization does not require the summation of power. The devices have a tunnel structure. Research is harmful to people with fear of enclosed spaces, so scanning is performed by open installations. The free sides allow you to exclude phobias, to be close to close people.
MRI - features of carrying out
MRI is a fairly new way to conduct research, without which it is already impossible to imagine modern diagnostics. Using a strong magnetic field and special measuring antennas, a step-by-step scanning of the body is performed. Its difference from x-rays and computed tomography is that during the procedure the patient is not exposed to any radiation.
Preparation for the procedure
Usually for MRI some special training is not required, but the patient should heed the advice of a doctor and take off all metal objects: jewelry, accessories, clothes with metal fasteners, as well as glasses, a hearing aid, and possibly orthodontic appliances.
The fact is that under the influence of a magnetic field they can all heat up and, in the worst case, even lead to burns.
It is also necessary to notify medical personnel about the bolts and plates used in the body used to hold bones, artificial joints, an artificial heart valve, stents, dentures, an intrauterine device, and tattoos made with metal-based paints.