Summary of the article
What is an MRI ?
MRI allows to visualize very precisely almost all parts of the body using protons present in water molecules. The hydrogen atoms react to radiofrequency waves which are sent by the machine by absorbing energy. Excited, they then release the accumulated energy and produce a signal which is read and converted into an anatomical image.
Apart from the lungs, which are not explored by this technique, MRI is highly effective in analyzing the brain, the spine, the joints and soft tissues. It can detect infectious or inflammatory lesions, vessel abnormalities, ligament or meniscus injuries and tumors.
MRI does not use ionizing radiation such as radiology or CT, so it is not irradiating.
It is composed of a tunnel that includes a large magnet and different antennas that will be used to explore a region of the body. Outside the examination room, a computer console allows medical and paramedical professionals to program images and their interpretation sequences.
What is an MRI performed ?
Depending on the organ to be studied, it takes 15 to 45 minutes to undergo an MRI. Under the responsibility of the radiologist, you will be taken care of by a radiology technician.
Unless otherwise indicated, remember to go to the bathroom to avoid any urge during the examination, which may be a little long.
Before entering the room, you'll be asked about your medical history. The health professional will make sure that you have no absolute or major contraindications. It is important to mention :
If you have a pacemaker or any other implantable electronic system- If you have had heart or head surgery
- If you have a metallic foreign body in your body (ocular implant, prosthesis, surgical clips, metal splinters in the eyes, etc.)
- If you suffer from kidney failure or diabetes
- If you have ever had an allergy to a gadolinium-based contrast agent
- If you are pregnant or have become pregnant
- If you are claustrophobic (fear of being confined, locked up)
Preparing for an MRI
With the exception of a few examinations, no preparation is necessary. You do not need to fast, so you can eat, drink and take your medicines as usual.
On the day of the examination, please remember to present the following documents to the secretariat :
- Your health insurance card ("carte vitale") and complementary health insurance card ("mutuelle")
- Your prescription
- The contrast medium which has been prescribed when injected review
- Your previous reports and images related to the condition which will allow a comparison and a better follow-up (X-ray, ultrasound, scanner, MRI...)
- Your IMD card if you have had surgery
- Your blood test results
Preferably wear clothes that do not have zippers or snaps, avoid wearing jewelry and hairpins, otherwise you will have to remove them.
Contrast material for MRI
Certain indications require the injection of a contrast agent. The product used in MRI is based on Gadolinuim, which makes the pathogenic elements visible on the images.
The injection is a very common procedure in MRI and is generally very well tolerated. Unpredictable reactions of intolerance to contrast medium are very rare and occur more frequently in patients with a history of allergies. They are usually transient and not serious.
In most cases, you will be prescribed a creatinine test to check your kidney function. If you suffer from kidney failure, the injection will (unless absolutely necessary) canceled.
Generally well tolerated, there are some small risks associated with the injection :
- Hematoma caused by the placement of a peripheral venous voice. Without gravity, it will subside in a few days
- Subcutaneous leakage of the contrast product. This is due to the pressure during the injection and generally present no serious consequences
- Nausea or vomiting.
- Urticaria which is more rare
- A rare allergic reaction like eczema, asthma or cardio-respiratory disorders
- Nephrogenic systemic fibrosis, which occurs exceptionally in cases of renal insufficiency
Depending on the severity of the reaction, you will be given a treatment and referred for allergy screening.
In all cases (unless otherwise advised by your doctor), if you have been given a contrast agent, drink two liters of water after the examination. This will help to eliminate the medication quickly.
Image interpretation
The interpretation of images can be done at the end of the examination if a radiologist is able to analyze images immediately or later when a tele-radiology service is set up.
Before going home, the secretary will give you the report and the images, often burned on a CD. If it is not possible to print the results in this form or if the center has opted for tele-radiology, you will have access to your results online using a secure connection to a patient account.
What are the risks of an MRI ?
There is no known biological risk related to the magnetic field.
The risks associated with contrast medium injection are low : see Contrast material for MRI.
If you have a pacemaker, heart valve or any foreign metal body implanted in your body (especially in the head), this represents a major risk factor if it is not reported to the medical team.
MRI categories
Click on the title of the examination to display the details.
Legal notice - Politique de Protection des Données - CGU
Copyright © 2020 - 2024 Alphath Access ltd. All rights reserved
