MRI or magnetic resonance imaging is medical check up which uses magnetic technology and radio waves to generate pictures of organs, bones, and tissues in the body.
MRI is useful to assist doctors in diagnosing a condition as well as determining the treatment plan that will be used. In addition, doctors can also use MRI to monitor the effectiveness of the patient's treatment.
Unlike X-rays or CT scans, MRI does not emit radiation, so it is relatively safe for children and pregnant women. However, to increase the accuracy of the image, sometimes a special dye (contrast) is injected through a vein.
MRI Indications
An MRI is performed on organs, bones, and tissues in the body to detect certain conditions. The following are some of the organs of the body that can be examined with an MRI:
- Brain and spinal cord
MRI of the brain and spinal cord can be done to detect head injuries, tumors, strokes, damage to the blood vessels of the brain, spinal cord injuries, disorders of the inner ear and eyes, as well as multiple sclerosis.
- Heart and blood vessels
Some conditions of the heart and blood vessels that can be detected with an MRI are blockage of blood flow, heart disease, heart damage after a heart attack, aortic dissection or aneurysm.
MRI can also see structural abnormalities of the heart, including the size and function of the chambers of the heart, thickness, and movement of the walls of the heart.
- Bones and joints
An MRI of the bones and joints may be performed to detect bone infections, bone cancer, joint injuries, disc abnormalities in the spine, and neck or back pain.
In addition to the organs above, MRI can also be performed on the breast, uterus and ovaries, liver, bile ducts, spleen, kidneys, pancreas, and prostate.
Examinations related to the brain and spinal cord are usually carried out with a special MRI called functional magnetic resonance imaging (fMRI).
Functional magnetic resonance imaging can see a picture of the state of the brain and brain blood flow when the patient is doing activities, so doctors can find out which part of the brain is working actively when the patient is doing certain activities.
MRI alert
The MRI machine is equipped with a very strong magnetic force. Therefore, metal objects can interfere with the operation of the machine and the results of the MRI examination. Tell your doctor if you have metal or electronic implants in your body, such as:
- Artificial heart valve
- Pacemaker
- Implantable Cardioverter-Defibrillator (ICD)
- Prosthesis (artificial body part) of the knee or other joint
- Hearing aids that are placed in the ear (cochlear implant)
- Dental fillings
- KB spiral and KB implant
- Tattoos, because some inks contain metal
- Body piercing
For patients who have a history of or are suffering from kidney or liver disease, it is necessary to be careful and consult further with a doctor when undergoing an MRI examination using a special dye (contrast).
This also applies to patients who have a history of allergy to contrast agents, although the contrast agents used for MRI examinations are less at risk of causing allergic reactions than those used for CT scans.
In addition, for pregnant women who are still in the first trimester, it is advisable to consult a gynecologist before doing an MRI. Although generally safe, the effect of the magnetic field generated in MRI examination on the fetus is not fully understood.
The use of contrast in pregnant women should also be avoided, unless absolutely necessary.
Before MRI
The following are some of the preparations that patients need to do before undergoing an MRI procedure:
- Removing metal objects that stick to the body, such as jewelry, hearing aids, watches, belts, safety pins, dentures, glasses, wigs, or underwear that has metal components
- Wearing the special clothes given at the checkpoint during the procedure
- Leaving cell phones and other electronic items outdoors
- Inform the doctor if suffering claustrophobia, namely the fear of being in an enclosed space, so the doctor can give a sedative if it is needed
Patients can generally eat and drink or take drugs as usual before the MRI procedure is performed, unless there is a special prohibition from the doctor.
Only in certain cases, patients are advised to fast for 4 hours before the MRI examination. It depends on the area or body part to be examined.
MRI procedure
An MRI scan can take 15–90 minutes, depending on the part of the body being examined. The following are the stages of an MRI examination:
- The patient will be asked to lie down on a bed that has been adjusted to the needs of the examination.
- Officers will monitor and communicate with patients through intercoms connected in both rooms.
- During the examination the patient will be inserted into a tube-shaped MRI device with open ends at both ends.
- During the examination, the patient is not allowed to move so that the images are clear and not blurry.
- The MRI machine will start scanning to get detailed and in-depth images of the organs.
- During the examination, the patient can use earplugs to reduce discomfort caused by the sound coming from the machine.
- For patients who use fMRI, the patient will be asked to do several small activities, such as rubbing objects or answering questions given, to see which parts of the brain are activated.
MRI examination is painless. However, sometimes, the patient will feel a twitching sensation during the procedure. This twitch is normal, because the MRI process can stimulate nerves in the body.
After MRI
There are several things after an MRI that are important to know, namely:
- The patient was allowed to go home and resume normal activities after undergoing the MRI. However, for patients who are given a sedative before the examination, it is recommended not to drive a vehicle and operate heavy equipment for 24 hours.
- The results of the examination will be reviewed by a radiologist. If necessary, the doctor will advise the patient to undergo another examination or test to get a more accurate examination result.
- The results of the MRI examination can be received within a period of approximately one week after the examination.
- If abnormalities are found, the doctor will determine the appropriate treatment according to the patient's condition.
Side effects MRI
MRI examination is a relatively safe procedure, but still carries a risk of side effects. Some of the possible side effects are:
- Nausea, dizziness, and a metallic taste sensation in the mouth, due to an allergic reaction to the contrast agent
- Damage to metal or electronic devices embedded in the body, due to the magnetic field of the MRI that can attract these objects
- Acute renal failure in patients with renal impairment, due to the use of contrast agents
