MRI (magnetic resonance imaging) is a method of examining organs and tissues, which in many cases is of decisive importance in setting up an accurate diagnosis and prescribing treatment. The method makes it possible to obtain a detailed image, which allows to reveal the smallest signs of the pathological process.
Most often, MRI is used to diagnose organs of the central nervous system, musculoskeletal system, internal organs, spine. Visualization is due to the measurement of the electromagnetic response of hydrogen atoms in response to their action by electromagnetic waves in a highly stressed magnetic field. The informative nature of the method is increased by the use of contrast agents.
Is the MRI procedure harmful?
Magnetic resonance imaging is considered harmless to the body procedure, which is confirmed by numerous studies. But despite this, there are some contraindications to its carrying out, therefore it is necessary to do an MRI only according to the doctor's indications and take into account the safety measures.
It should be understood that contraindications for MRI are not related to possible harmful effects of the method, but to individual patient characteristics and limitations related to the need to stay in a closed space under the action of a magnetic field. This is due to the influence of the field on metallic, electronic and ferromagnetic objects that can be found in the human body. Magnetic impact can lead to a disruption in their work, displacement.
Contraindications to MRI
All the factors, in which the passage of magnetic resonance imaging becomes impossible, are divided into two groups: relative and absolute contraindications. Relative contraindications are factors in which the procedure can be prescribed, but with certain conditions. The presence of absolute contraindications is a prohibition for this diagnostic method, which can not be canceled forever or for a long time.
So, relative contraindications MRI are:
- Decompensated heart failure ;
- pregnancy (first trimester);
- insulin pumps;
- artificial heart valves;
- hemostatic clips;
- stimulators of the nervous system;
- claustrophobia (for examination in tunnel tomographs);
- tattoos on the body, made with metal-containing colorants;
- general severe condition of the patient.
Absolute contraindications for MRI are as follows:
- presence of a pacemaker;
- installed Ilizarov's apparatus;
- large metal implants, ferromagnetic fragments;
- implant of the middle ear;
- intracranial hemostatic clips made of metal.
The above contraindications refer to the MRI of the head (brain), spine , abdomen, mammary glands and any other areas of the body. If the patient does not have any contraindications to the study, the MRI can be repeated many times.
Contraindications to MRI with contrast
In some cases, MRI is required with the use of contrast - a special drug administered intravenously and allowing "flashing" the internal organs. As a rule, contrast preparations do not cause allergic reactions and side effects, do not have a negative effect on the body. Therefore, contraindications for MRI with contrast agent include only the first trimester of pregnancy (at this time, the fetus is most susceptible), as well as individual intolerance of the components of the contrast agent.