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Magnetic resonance imaging, also called MRI or MR, is a modern and very accurate examination, showing sections of internal human organs in all planes. What are the indications for an MRI? How do I prepare for an MRI and how is it done?

Magnetic resonance imaging(akaMRI- magnetic resonance imaging) uses the magnetic properties of atoms that make up everything, including human body. To perform the test, you need a strong magnetic field, radio waves and a computer that converts data into images. Many types of magnets are used, which differ in the intensity of the produced field. The higher the magnet power, the better the results.

Only devices generating a very strong magnetic field can perform spectroscopy, functional tests and ultrafast vascular examinations.

For good signal reception from the human body, theMRIsystem must be isolated from all external electromagnetic waves. Therefore, the apparatusMRIis placed in the so-called Faraday's cage.

Open and closed MRI

In terms of construction, there aretwo types of MRI machines :

  • open magnetic resonance imaging- allowing access to the patient from three sides
  • closed magnetic resonance imaging- the patient is placed in the magnet tunnel

Magnetic resonance imaging - indications

With the help of resonance, very good images of the muscular and skeletal system, especially the spine and the surrounding spaces, are obtained.

It also works well in the diagnosis of cancer and inflammatory processes.MRIvery well visualizes blood vessels, heart cavities and the heart muscle. It enables the detection of elements invisible in the X-ray examination, e.g. bone marrow. Detailed indications for the testMRIis:

on the part of the central nervous system

  • demyelinating diseases (e.g. multiple sclerosis)
  • dementia (e.g. Alzheimer's disease)
  • brain tumors difficult to assess in other studies
  • assessment of structures around the pituitary gland, eye socket, back of the skull (including stroke diagnostics, etc.)
  • tumors of the spinal canal (spinal cord)
  • ratinganatomical structure of the spinal canal
  • radiation changes in the central nervous system
  • unexplained neurological disorders;

on the soft tissue side

  • soft tissue tumors (inflammatory, cancerous)
  • injuries of soft tissues (joints, muscles, ligaments);

on the side of the thorax, mediastinum and pelvis

  • heart tumors
  • large vessel disease
  • lung tumors infiltrating the chest wall
  • cancers of the reproductive organs in women
  • prostate cancer in men

Magnetic resonance imaging: the course of the examination

Depending on the type of device, the complete procedure may take 10-30 or 30-90 minutes. The patient is placed on a retractable table in the center of the scannerMRI . It should make it very comfortable because it has to lie still so that the image is not distorted.

If the patient is unable to lie down due to illness, sedation or even general anesthesia should be given. Additional lighting and ventilation are installed inside the tunnel to increase comfort.

The patient inside the magnet is in constant contact with the staff (through the microphone and the TV camera).Each MRI sequence lasts from 3 to 10 minutes .

During this time, the patient hears a knocking sound with an intensity similar to a spinning washing machine. Sometimes, during the examination, the patient wears noise-reducing headphones. When several images need to be taken, the table automatically moves to the appropriate position, but the patient remains motionless.

Magnetic resonance imaging with contrast

In some cases, a special contrast agent is injected to improve the image quality. The use of contrast in magnetic resonance imaging allows not only the assessment of the structure, but also the function of tissues and organs.

It is used to test, for example, renal secretion, inflammation foci, and the blood supply to tissues and organs. ContrastsMRare safe, they can be used even in patients allergic to X-ray contrast.

Testing contrast agentsMRdo not interact with other medications and are entirely excreted.

Magnetic resonance imaging: contraindications

An implanted pacemaker is an absolute contraindication to the examination. The magnetic field generated by the MRI machine may interfere with the pacemaker operation, which poses a threat to the he alth and life of the patient.

A patient with a pacemaker cannot even enter the room in which he is locatedmagnet. Similar disturbances caused by the magnetic field may occur in the work of neurostimulators.

Caution should be exercised in the case of people who, due to an injury, may have metallic foreign bodies, e.g. iron filings in the area of ​​the eye sockets. The magnetic field can displace the foreign body and damage the eyeball. When the presence of a foreign body is suspected, prior ophthalmological consultation and X-ray pictures are recommended.

A relative contraindication for MRI is a contraceptive intrauterine device (if it is made of metal), an artificial heart valve, prostheses and vascular clips, and metallic orthopedic implants: artificial joints, wires, screws, stabilizers. Pregnant women should inform the attending physician about their condition.

Magnetic resonance imaging - is it safe?

The test is completely painless, does not cause any biological reactions, does not interact or interfere with the course of pharmacological treatment.

After its completion, you can drive a car. Although the strength of the magnetic field is 20,000 times greater than that of the Earth, it has no detrimental effect on the he alth of the subject. About several million studies have been carried out in the last few years with no known side effects.

If the patient is taking any medications, he or she must ask the doctor who is referring the MRI about whether they can be taken before and after the examination. When going to the examination, it is better to give up makeup (cosmetics contain particles of non-ferrous metals) and hairspray, as this may affect the image production.

You don't need to fast. The temperature in the test room can reach 25-26˚C, so dress lightly.

Clothes are not removed, but patients should remove all metal objects (even removable dentures) as they may affect image formation. You should also inform your doctor about metal implants.

  • Computed tomography: indications and the course of the examination
  • PET-CT Emission Tomography - what does the examination look like? Indications for PET-CT
  • Computed tomography (CT, CT) of the head - X-ray examination of the brain
  • Magnetic resonance imaging of joints
  • Magnetic resonance imaging of the spine
  • fMRI, i.e. functional magnetic resonance imaging

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