MAGNETIC RESONANCE IMAGING

 


MAGNETIC RESONANCE TESTING

 

Magnetic resonance imaging, or MRI for short, is a way of obtaining highly detailed images of organs and tissues in the body without the use of x-rays. Instead, MRI scans use a strong magnetic field, radio waves, and a computer to produce images that identify potential injuries or disease processes. In this exam, the patient is placed in the MR machine - usually a long tunnel-shaped magnet that is open at both ends. Then, thanks to radio waves, signals are generated, captured by the receiver in the MR scanner. These signals are processed by a computer processor to produce highly clear tissue images. MRI is painless and the magnetic field does not cause any known tissue damage. The MR scanner may make loud noises (knocking) from time to time during the examination; the use of earplugs or headphones helps to avoid exposure to this noise.

Indications for MRI examination

 

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. MRI visualizes blood vessels, heart cavities and the heart muscle very well. It enables the detection of elements invisible in the X-ray examination, e.g. bone marrow. Detailed indications for MRI examination are:

 

1. On the part of the central nervous system:

 

developmental defects of the CNS

inflammatory diseases of the CNS; viral, bacterial, fungal, parasitic

demyelinating diseases (e.g. multiple sclerosis)

dementia diseases (e.g. Alzheimer's disease)

brain tumors difficult to assess in other studies

diagnostics of ischemic changes of the brain and spinal cord (stroke), especially in the early period (the first day), when these changes are invisible in computed tomography

anomalies and defects of cerebral vessels

assessment of the structures around the pituitary gland, orbit, and the back of the skull

tumors of the spinal canal (spinal cord)

anatomical assessment of the structures of the spinal canal, bodies, arches and vertebrae, and intervertebral discs

unexplained neurological disorders

soft tissue tumors (inflammatory, cancerous)

qualification for surgery due to degenerative changes, monitoring and evaluation of the effectiveness of surgery

injuries, infections, vascular malformations

varieties and malformations, bone marrow pathologies

vascular and demyelinating changes



2. On the side of soft tissues:

 

soft tissue tumors (inflammatory, cancerous)

injuries of soft tissues (joints, muscles, ligaments);

3. On the side of the chest, abdomen and pelvis:

 

heart tumors

large vessel disease

lung tumors infiltrating the chest wall

tumors of the reproductive organs in women

prostate tumors in men

verification of an ambiguous image in computed tomography when performing a tomographic examination is inadvisable, e.g. allergy to contrast agents or in patients who received high doses of ionizing radiation.

disseminated, focal changes in the liver and other parenchymal organs, primary and secondary proliferative processes

kidney after transplantation

cholelithiasis

focal changes of the adrenal glands

colon tumors (sigmoid colon, rectum)

other inflammatory and neoplastic processes of the small pelvis

4. On the part of the vascular system:

 

diagnosis of aneurysms and arteriovenous malformations.

high sensitivity of MR angiography - recommended as screening tests in the diagnosis of cerebrovascular defects.

PREPARATION FOR MR EXAMINATION The MRI

 

examination does not require special preparation on the part of the patient. However, since there is a strong magnetic field in the Resonance Laboratory, there are several important rules regarding the course of the examination. Before entering the room with the MR scanner, it is recommended to inform the laboratory staff about the presence of metal implants and remove all metal objects from pockets and hair, as they may interfere with the course and results of the examination. Before starting the study, the patient will be asked to complete an appropriate questionnaire. One of the issues discussed will be items that may pose a health hazard or other problem during an MRI scan.

Absolute contraindications for performing magnetic resonance imaging;

- cardiac pacemaker or implanted defibrillator

- inner ear cochlear implant

 

Relative contraindications for MRI examination;

- artificial heart valve

- pregnancy (especially in the first trimester) and lactation (in the case of testing contrast)

- Clip from metal ferromagnetic established in order to avoid bleeding intracranial aneurysm

- an implanted or external pump for drug delivery

- a metal foreign body close to the eye e.g. metal filings

- vascular clips, staplers, surgical clips, stents, spirals or intravascular filters

- limb or joint prosthesis, ortpedic implants, screws, wires, rods, clips, plates

- permanent makeup, tattoo, intrauterine device

- claustrophobia

 

The problem of claustrophobia.

 

Some patients undergoing an MRI scan may feel confined or confined in the scanner space. In our laboratory, thanks to modern medical equipment, we can perform part of the tests in a more comfortable position for this type of patients, i.e. in the position with the feet facing the gantry, so that the patient's head remains outside the apparatus. People suffering from this disease feel in this position definitely safe and usually it is possible to complete a test that was impossible in other laboratories due to the feeling of being closed and anxious. In very rare cases, it is recommended to administer a sedative to avoid feeling anxious. In our studio, we also allow the presence of an accompanying person in the room with the MR scanner, which can also calm the patient down.

 


If the patient is properly prepared and knows what to expect during the examination, the examination is almost always smooth. The medical staff of our studio provides you with help and professional service.

Pregnancy and MR examinations.

 

If the patient is pregnant or suspects that she is pregnant, inform the MRI technician at the time of the interview. In general, there is a lack of data on the safety and risks of performing MRI scans in pregnant patients. However, such tests are performed in pregnant patients in order to clarify very important problems or suspected abnormalities. MRI is not recommended in the first trimester of pregnancy. In each individual case, the decision to perform the examination or to withdraw from it is made by the referring physician.

 

Breast-feeding.

 

The technician should be informed that you are breastfeeding if you have an MRI scan, during which you may need to use a contrast agent. One option in this situation is to express the food before the test for use, until the administered contrast agent is eliminated from the body, which usually takes about 24 hours.

 

Safe and pain-free

 

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 (also after administration of a contrast agent). Although the strength of the magnetic field is 20,000 times greater than that of the Earth, it has no detrimental effects on the health of the subject. About several million studies have been conducted in the last few years without any known side effects. MR scanners are air-conditioned and well-lit. Some scanners emit music to help the patient relax during the test.

 

Contrast agents for MR examinations

 

To improve imaging, a gadolinium contrast agent may be administered intravenously in some MRI scans. The radiologist decides about the administration of this agent during the MR examination. The mechanism of action of the contrast agent administered to the patient during the MR examination consists in its accumulation in the examined tissue in order to strengthen or weaken the received signal. This enables images of different contrast to be obtained depending on the type of tissue examined, and a more detailed visualization of abnormalities. Unlike X-ray contrast agents, gadolinium contrast media does not contain iodine and therefore rarely causes allergic reactions. If you have a history of kidney disease or failure, kidney transplantation or liver disease, in this case, inform the MR technician before taking a gadolinium contrast agent. If you are unsure about these conditions, discuss the matter with the examining radiologist.

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