MRI or magnetic resonance imaging is a type of imaging using magnetic technology and radio waves to obtain detailed and in-depth images of organs, bones and tissues in the body. Unlike X-rays or CT scans, MRI does not emit radiation and is considered safer for pregnant women if needed.
MRI is an examination that is used as a diagnostic aid for doctors. Some of these are examinations relating to the brain, spinal cord, heart, blood vessels, bones, joints, soft tissues, and other body organs. To improve the accuracy of the image, sometimes a special coloring agent (contrast) is needed which is injected through a vein.
MRI indications
MRI imaging can be done on a number of organs to detect certain conditions, for example:
- Brain and spinal cord, to detect head injuries, cancer, stroke, damage to blood vessels in the brain, spinal cord injury, tumors, abnormalities in the eye or inner ear, and multiple sclerosis.
- Heart and blood vessels, to detect blood flow disorders or inflammation in blood vessels, heart disease, heart damage after a heart attack, aortic structural abnormalities such as aortic dissection or aneurysm, and abnormalities in the structure of the heart organ which include the size and function of the heart chambers, thickness and movement heart wall.
- Bones and joints, to detect bone infections, bone cancer and joint injuries.
In addition to these organs, MRI can also be performed on other organs, such as the breast, uterus and ovaries, liver, bile ducts, spleen, kidney, pancreas, or prostate.
For certain cases, such as epilepsy, brain tumors, and strokes, a test called functional magnetic resonance imaging (fMRI) can be performed, which is to see a picture of the state of the brain and cerebral blood flow when the patient engages in activities.
Although relatively safe, what you need to look out for is if you have metal or electronic implants in the body such as knee prostheses, artificial heart valves, and pacemakers. Also if you are pregnant (especially in the first trimester) or are breastfeeding. Also, tell your doctor if you are allergic to injections of special coloring or sedatives (sedatives) so that the medication can be adjusted.
MRI warning
MRI machines are equipped with very strong magnetic forces, therefore metal objects can interfere with the workings of the machine and the results of procedures. Tell your doctor if you have metal or electronic implants in the body, such as:
- Artificial heart valve.
- Pacemaker.
- Implantable Cardioverter-Defibrillator (ICD).
- Knee prostheses or other joints.
- A hearing aid mounted in the ear (cochlear implant).
- Dental fillings.
- Spiral KB and implant KB.
- Tattoos, because some types of ink have the potential to contain metals.
- Body piercing.
For those who have a history or are suffering from kidney or liver disease, it is necessary to be careful when using an MRI examination using a special coloring agent (contrast). This also applies to patients who have a history of allergies to contrast agents, even though the contrast agents performed for MRI examinations cause fewer allergic reactions when compared to the contrast agents used for CT scanning.
Although not exposed to radiation and considered safe, pregnant women who are still in the first trimester stage are advised to consult a doctor before performing an MRI, because the effects of magnetic fields on the fetus are not yet fully known. The use of contrast in pregnant women should also be avoided.
For people with claustrophobia, ie fear of confined spaces, they may feel uncomfortable during the procedure. For this reason, sedatives will be given if needed.
Before MRI
The following are some preparations that need to be done by the patient before undergoing an MRI procedure.
- Removing metal objects attached to the body, such as jewelry, hearing aids, watches, belts, safety pins, artificial teeth, glasses, wigs, or underwear that have metal components. Patients will usually be given special clothing to wear during the examination.
- Leave your cellphone and other electronic items outdoors.
Patients can generally eat and drink, or take medicines as usual before the MRI procedure is carried out, unless there is a special prohibition from the doctor.
For patients who need injection of dyes (contrast) containing gadolinium, the doctor will inject it into the arteries of the arm, either before or in the middle of the procedure. The patient can feel a metal sensation in the mouth when the drug is injected.
MRI procedure
After doing all the preparations, the patient will lie down on a flat bed that can be positioned according to the scanning requirements. MRI rooms are only allowed for patients, and radiologists will operate machines from other rooms, while monitoring and communicating with patients through intercoms that are connected in both rooms. If needed, the patient's family or relatives can accompany him in the room, removing all clothing or metal objects.
The patient's body will be inserted into a long tube that has holes at both ends. Patients are not permitted to move during the scanning process so that the image results are clear.
The MRI machine will begin scanning using the power of magnets and radio waves to get detailed and in-depth images of the body. During this process, the patient will hear sounds such as beats, claps, clicks, or other sounds that are loud enough. In this case, earplugs or headsets can be provided so that the sound does not interfere with patient comfort.
No pain is felt during the procedure, but sometimes, the patient will feel a sensation of twitching during an MRI procedure. This is normal because the MRI process can stimulate nerves in the body.
For patients using fMRI, the radiologist will ask the patient to do a number of small things, such as tapping the thumb of the hand against another finger, rubbing an object, or answering questions given to see brain signals when the activity is carried out.
In general, MRI procedures require 20-90 minutes, depending on the size of the area examined. MRI results will be read first by a radiology specialist, before being given to patients. Usually, it takes 1-2 weeks, but results can be obtained early if the patient's condition is urgent.
After MRI
In general, patients are allowed to go home or resume activities as usual after an MRI is performed. However, patients who are given sedatives, are not allowed to drive a vehicle and operate heavy equipment for 24 hours. It is recommended to contact family or relatives to drive home.
MRI complications
Since MRI does not emit radiation, the potential for complications is minimal. Although rare, complications caused by allergic reactions to drugs, such as contrast agents or sedatives given, can occur. Filtering objects attached to the body, especially electronic and metal-based devices is important before an examination is carried out, because the magnetic field in an MRI examination can attract metal objects or electronic devices. This risks causing injury.
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