Magnetic resonance imaging (MRI) is a non-invasive modern diagnostic test method that allows you to visually examine deeply located biological tissues. It is based on such a physical phenomenon as nuclear magnetic resonance. This can be understood from the name of this method. When used, the electromagnetic response of the atomic nuclei is measured. Most often, hydrogen atoms are used.
An MRI scan is what?
Human tissues are saturated with hydrogen. This allows you to examine organs and tissues, using the features of the magnetic waves of this chemical element.
A proton (a positively charged particle) of a hydrogen atom has a spin (magnetic moment), which is able to change its location in space upon exposure to a powerful magnetic field. In an external magnetic field, its spin will be co-directed or oppositely directed with respect to this field. This is the basis for the diagnosis of MRI.
The investigated region is affected by electromagnetic radiation of a certain frequency. In this case, some protons change their magnetic moment to the opposite one, after which they return to their initial position. At the end of exposure to electromagnetic radiation, a charged hydrogen particle releases the energy of relaxation. This energy is recorded in this process by special equipment (tomograph).
What is it used for?
MRI is a study that allows you to get an accurate picture of all the soft internal organs and tissues of the body (the brain and spinal cord, cartilage, etc.). This method of investigation makes it possible to detect even the smallest changes and inflammatory processes, to determine the rate of movement of biological fluids (blood, lymph, liquor), to see the reaction of the cerebral cortex to a change in the work of an organ. Tissues with low water content (lungs, bones) are not examined using tomography, because their image is of poor quality. This research is widely used in neurosurgery and neurology. This method can have some contraindications.
Research MRI has its contraindications. They can be absolute and relative. Absolute contraindications suggest that this study can not be performed under any circumstances. With relative contraindications, MRI is undesirable, but it is permissible if absolutely necessary.
- Metal implants.
- Ilizarov apparatus with metal construction.
- Implants of the middle ear with magnetizable metal components or electronic.
- Insulin pumps.
- Stimulants of the nervous system.
- Artificial heart valves.
- Implants of the inner ear are nonferromagnetic.
- Hemostatic clamps.
- Nonferromagnetic vascular clips (clamps) with intracranial aneurysms.
- Heart failure during decompensation.
- Claustrophobia (panic fear of confined space).
- Mental illness and inadequate patient condition.
- Alcoholic intoxication.
- Very serious condition of the patient.
- The first trimester of pregnancy.
- Tattoos that are made with dyes that have metallic components.
Titanium dentures do not serve as a contraindication for research, because they are non-ferromagnetic. In addition, there are weight restrictions for the passage of MRI. Weight of the patient should not be more than 120 kg.
The presence of an intrauterine device, breast feeding and menstruation do not serve as a contraindication for MRI. The final decision on refusal in carrying out this procedure is taken by the doctor-radiologist MRI.
How does the examination?
How do MRIs work? For this procedure, no special training is required. An exception is an MRI of the pelvic organs. On the eve of the procedure, you can take food, but in moderation. The patient is offered to remove all accessories (watches, hair clips, jewelry), as well as dentures, a hearing aid and a wig, if such items exist. In addition, credit cards and bank cards also need to be left outside the cabinet, because they can deteriorate. All metallic and metal-containing items, as well as electronic items, must be left behind the door, since they can disrupt the magnetic field that is created during the examination procedure. This will reduce the quality of the images. In addition, this magnetic field can spoil the electronics.
In case the patient has any metal prosthesis, artificial heart valves, implanted electronic devices, etc., it is necessary to inform the doctor about it. Diagnosis of MRI in some cases may be contraindicated (as discussed above) because of possible harm to the patient's health, as well as the impact on the result of the examination. If the doctor decides that there are no contraindications, the patient will be invited to the office for a survey. Some clinics offer to change into a robe, but you can stay in your clothes if there are no ferromagnetic materials on it.
So, how do MRIs work? To perform this procedure, the patient lies in the tunnel of the tomograph. During the study it is important to maintain absolute immobility. The quality of the pictures depends on this. The tunnel lights up and the fan works, in order to make it easier to breathe. Also there is a built-in microphone. If necessary, you can talk with a doctor who conducts a survey.
Some examinations are carried out with a contrast agent. If necessary, the contrast is injected into the vein at the elbow of the arm.
How long does the procedure last?
This type of research lasts from 15 to 45 minutes. After finishing the procedure, the patient may be asked to stay a little until the moment when his pictures are fully understood by specialists, and there is no certainty that they have been performed qualitatively, that is, there is no need to do additional ones.
MRI for young children
Usually MRI is prescribed for children if the doctor has suspicions of pathology, in which the probability of damage to the structures of the brain is high. Surveys of other internal organs using this method, children are prescribed less often.
This procedure is recommended for children after 5 years. It is very important that the child lies motionless during the study. It takes from 15 to 40 minutes. It is clear that it is very difficult to sustain such a time without movements to a small patient. If the child behaves uneasily during the research, the pictures will be of poor quality and will not carry any information for the doctor.
Mom is allowed to be in the office while examining her child. The device has a built-in microphone and the ability to talk with the baby during the procedure.
In extreme cases, if you can not do without this research, you can do MRI for children and younger children. But in this case for the immobilization of the child is allowed the use of anesthesia.
MRI for free under the OMC policy
Every citizen of the Russian Federation has a medical insurance policy. Is it possible to do an MRI on the MHI policy for free? The answer is yes, but not always. In medical insurance is included in the list of free services. If the diagnosis of MRI during registration of the policy was included in this list, then in a public medical institution where there is a tomograph, it is easy to go through this procedure for free. But for all this research can not be done free of charge. After all, MRI is a high-tech and expensive study. In the state polyclinics, however, there are free quotas for MRI. But there are not many of them, only a few procedures a month. If necessary, such a quota can be obtained. For the passage of this diagnostic procedure free of charge, the patient should have an informed referral from the attending physician. If there is such a direction, the patient can queue for this type of diagnosis, or if you can go through the procedure at any time convenient for the patient. The doctor should tell where exactly it is possible to pass an MRI for free. If doctors can not give such information, you can contact your insurance company directly.
You can pay for the MRI procedure both in public medical institutions and in commercial clinics. As you already understood, MRI services are not cheap. The cost depends on the type of equipment used for research, the prestige of the clinic and its distance from the city center. In addition, at night, an MRI is somewhat cheaper. Usually this procedure in clinics is a system of discounts, but it needs to be learned in advance. So, for example, the following categories of citizens can receive a discount on MRI in 5%:
- Participants and veterans of wars.
- Liquidators of the Chernobyl accident.
- Invalids of the first and second group.
- Participants of the Second World War.
- Medical workers when presenting a diploma of medical education and a certificate from the place of work that the citizen is currently working on the specialty.
The price also depends on the use of contrast medium during the MRI procedure. The cost of research with contrast will be higher than without it. The accuracy of diagnosis using this substance is increased many times.
The cost depends on the examination area. The average price for examining one zone without contrast is from 3500 to 8000 rubles.
Can it hurt the health of MRI?
If all the necessary requirements are met (to remove all metal and electronic items) this kind of research can not do much harm. At least until now no such cases have been recorded. X-rays are not used here, so the procedure can be repeated as many times as needed.
If a patient has a pregnancy of up to 12 weeks, doctors assume that there is a small risk to the fetus, but this assumption is purely theoretical. Patients suffering from claustrophobia should warn the specialist who will perform the research before carrying out the procedure. In this case it is permitted to invite one of the close relatives to the procedure.