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What is an MRI?

Magnetic Resonance Imaging is a type of medical imaging that produces detailed images of most of the body’s internal structures, including organs, bones, muscles, and blood vessels. The MRI machine produces these images using a large magnet and radio waves, and harmful rays such as X-rays are not used in this imaging method. These images will give your doctor important information in diagnosing the disease and planning its treatment.

?How does an MRI work

The waves used in MRI are radio/magnetic waves that do not harm the body. MRI uses the physical fact that the protons that are placed in the nucleus of atoms rotate around the axis of the earth at a high speed, and as a result, they form a magnetic field around them.

In MRI, the patient is placed in a very strong magnetic field. This field causes the axis of rotation of protons in the nucleus of atoms in all tissues of the body (especially the protons in the nucleus of the water molecule) to be along the MRI magnetic field lines.

Then special radio waves are radiated to the patient’s body. These waves, which are sent as pulses, cause the rotation axis of protons to change slightly.

At the end of the radio pulse, the rotation axis of the proton returns along the lines of the magnetic field. This return creates a new radio (electromagnetic) wave.

Then these secondary radio waves that are emitted from each proton are received by the receivers of the MRI machine and sent to its computer. The MRI computer is very powerful and has high computing power.

In this computer, the received waves are quickly analyzed and then images are created based on these analyzes that the doctor sees on the monitor of the device and prints them if necessary.

In the MRI computer, it is determined which parts of the body emit more radio waves. The higher the intensity of the wave received from a point of the body, the more proton density there is, and since the most abundant atom in the body that has protons is the hydrogen atom that is in the water molecule, so wherever the radio wave is sent, there is actually more water. had.

In fact, what MRI does is to show where there is more water in the body. Because the concentration of water molecules in the tissues of the body is different, and this concentration changes again when the tissues become sick, it is possible to create a very accurate picture of the shape of the various tissues of the body using the received information.

One of the distinguishing points of this method with CT scan is that in MRI, the images of soft tissues such as cartilage, tendon, ligament, nerve and veins are seen very clearly and precisely, and this imaging method is especially useful for diagnosing diseases of this tissue. It is useful.

After MRI, it is mostly used to check the problems of the soft tissues of the body, while the CT scan is more useful for checking the bones and its lesions and injuries.

MRI is an imaging method that helps the doctor to diagnose the disease. By referring to Dr. Mehrdad Mansouri, an orthopedic specialist, identify the main cause of your limb, back, or hip pain and treat your pain fundamentally.

Is MRI dangerous or safe?

If safety principles are followed, MRI is a very safe and low-risk imaging method. About 10 million people do MRI every year. MRI is completely painless and has no known short-term or long-term complications.

As mentioned, MRI uses a very powerful magnetic field. If metal objects are placed in this magnetic field, they will move. The movement of these objects can cause harm to the patient.

Therefore, there should not be any metal objects in the MRI room. If the patient has a metal device with him, he must remove it outside the MRI room. Watches, jewelry and some parts of clothes are metal.

If the patient has already undergone surgery and metal clamps have been used on his veins, doing MRI is dangerous for him because the metal clamp can move in the MRI magnetic field.

Metal bullets or shrapnel in the patient’s body can cause the same problem. In those who use hearing aids or those who have cardiac pacemakers, MRI magnetic waves can interfere with the operation of these devices.

?Is MRI a Harmful imaging method

If safety principles are followed, MRI is a very safe and low-risk imaging method. About 10 million people do MRI every year. MRI is completely painless and has no known short-term or long-term complications.

As mentioned, MRI uses a very powerful magnetic field. If metal objects are placed in this magnetic field, they will move. The movement of these objects can cause harm to the patient.

Therefore, there should not be any metal objects in the MRI room. If the patient has a metal device with him, he must remove it outside the MRI room. Watches, jewelry and some parts of clothes are metal.

If the patient has already undergone surgery and metal clamps have been used on his veins, doing MRI is dangerous for him because the metal clamp can move in the MRI magnetic field.

Metal bullets or shrapnel in the patient’s body can cause the same problem. In those who use hearing aids or those who have cardiac pacemakers, MRI magnetic waves can interfere with the operation of these devices.

?What points should be considered before an MRI

MRI uses a very powerful magnetic field and metal objects move in this field, so no metal object should enter the MRI room with the patient.

It is better for the patient to leave his watches and jewelry at home and not bring them with him. In some cosmetics, there are metal materials, so the patient is advised not to use cosmetics.

The clothes worn by the patient should not have any metal parts. Some buttons and clips are metal.

The following objects should not enter the MRI room:

  • Cash or credit card
  • Electronic objects such as mobile phones
  • hearing aids
  • Watches or jewelry
  • Key, coin or pen
  • hair clips
  • Clothes that contain buttons, clips, hooks, zippers, or threads that contain metal
  • Shoes or belts

To ensure that metal objects do not enter the MRI room, they usually ask the patient to remove all their clothes and give them a disposable medical gown to wear.

Then the patient enters the MRI room without anything else. However, metal objects may be inside the patient’s body for any reason. After each patient who intends to undergo MRI, he is asked about the presence of the following objects in his body

  • peace maker
  • Cardiac defibrillator
  • Aneurysm clip neurostimulator
  • Screws and plates or other metal objects used to treat bone fractures
  • Automatic drug injection devices
  • Foreign metal objects that have already entered the body, especially in the eye
  • Shot or shrapnel in the body
  • tattoo
  • Metal tooth clip
  • Some types of IUDs
  • Medical patches containing metal

?How is MRI performed

The MRI machine is usually in the form of a small room with a tunnel inside. There is a bed in front of this tunnel that can move into it.

To perform MRI, the patient lies on the bed and then goes into the tunnel. During imaging, the patient’s bed moves inside the tunnel. The duration of imaging with MRI is longer than CT scan. This period is usually between 15 and 45 minutes.

Sometimes this may take up to an hour. The patient must be calm and motionless while the device is working. The movement of the patient causes the obtained image to be blurred and inaccurate.

During the MRI, the patient can breathe easily. Of course, the technician may ask the patient to hold his breath for a few moments.

During the MRI, loud noises may be heard from the device, which is normal and should not cause concern to the patient. Headphones may be placed on the patient’s ears before the MRI to reduce noise.

You are alone in the MRI room, but the MRI technician sees you and hears your voice. So whenever you need help, speak up and say it.

The patient may be given medication before the MRI. If the patient is allergic to some drugs, he must inform the medical personnel present in the MRI room before injecting the drug. If the patient feels unwell after the injection, he should inform the medical staff immediately.

What preparations are needed Before an MRI?

It is mandatory to bring a copy of your Prescription and ID card on the day of the appointment.

If there is a metal object in the body, such as bullets, platinum, shrapnel, etc., inform the reception.

MRA is not performed for weight over 85 kilos.

Patients with an appointment at 7 am do not need to be at the center half an hour before their appointment.

Be at the center half an hour before your appointment. Otherwise, the appointment will be canceled and given to someone else.

It should be noted that in case of any change in appointments, the patient will be contacted, and in case of non-response, the patient is responsible.

Please inform the reception in case of any lung and kidney problems.

to do RI without injection:

Do not eat or drink 2 hours before your appointment.

MRCP:

Bring a simple pineapple juice (without pulp) with you.

Don’t eat fatty foods, red meat, fish, eggs, milk, buttermilk and soft drinks one day before.

Do not eat or drink 10 hours before your appointment.

It is necessary to bring doctor’s documents.

Other M.R.I with Contrast Media injection:

Do not eat or drink anything 6 hours before your appointment.

It is necessary to bring doctor’s documents.

Get the prescribed medicines from the pharmacy one day before the appointment and bring them with you two days before the appointment.

If you have any kind of lung or kidney disease, inform the reception.

MR Enterography:

24 hours before the appointment, eat only simple soup (without meat and beans).

Do not eat or drink 8 hours before your turn.

Be at the center one hour before your appointment.

It is necessary to bring doctor’s documents.

MRI with anesthesia:

Individuals over 13 years of age cannot be treated under anesthesia at the center.

Preparations before MRI with anesthesia:

Do not eat 8 hours before your appointment.

Do not drink breast milk 6 hours before the appointment.

Do not drink milk powder 4 hours before the appointment.

Do not drink water or sugar water 2 hours before.

Get the anesthetic prescribed by the receptionist from the pharmacy and bring it with you on the day of the appointment.

If the patient feels or has a cold, be sure to contact the center.

If you have any respiratory disease or special disease, be sure to inform the center.

F. Katibeh
F. Katibeh
MRI expert
M. Dizavandi
M. Dizavandi
Head of MRI Department
علی بابایی
علی بابایی
MRI expert
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