Important things to know before an MRI scan?
MRI uses powerful magnets, the presence of metal in your body can be a safety hazard if attracted towards the magnet. Even if not attracted towards the magnet, metal objects can disturb the MRI image. Before having an MRI, you'll have to complete a set of questions that includes whether you have metal or electronic devices in your body.
Unless the device you have is certified as MRI safe, you might not be able to have an MRI. Devices that are unsafe are listed below.
If you have tattoos or permanent makeup in your body anywhere which contains ferromagnetic materials, then ask your doctor or MRI technologists whether they might affect your MRI. Some of the darker inks contain metal Which Can Be Attracted to the Magnet.
Before you schedule an MRI, tell your doctor if you think you're pregnant. The effects of magnetic fields on fetuses aren't well understood. Your doctor might recommend an alternative exam or postponing the MRI. Also tell your doctor if you're breastfeeding, especially if you're to receive contrast material during the procedure.
It's also important to discuss kidney or liver problems with your doctor or MRI technologists.Because problems with these organs might limit the use of contrast agents during your MRI scan.
Before an MRI exam, you can have your food normally and continue to take your usual medications, unless otherwise instructed. You will be asked to change into a hospital gown and to remove things that might affect the magnetic imaging, such as:
The MRI machine looks like a long narrow tube that has both ends open. You lie down on a movable table that slides into the opening of the bore of the magnet.AMRI technologist monitors you from another room. You can talk with the technician by the microphone.
If you have a fear of enclosed spaces (claustrophobia), you might be given a drug to help you feel sleepy and less anxious. Most people go through the exam without difficulty.
The MRI machine produces a strong magnetic field around you and radio waves are directed at your body. The whole procedure is painless. You don't feel the magnetic field or radio waves and there are no moving parts around you.
During the MRI scan, the internal part of the magnet produces repetitive tapping, thumping, and other noises. You will be given earplugs or have music playing to help block the noise.
In some cases, a contrast material, typically gadolinium, will be injected through an intravenous (IV) line into a vein in your hand or arm. The contrast material enhances blood vessels. Gadolinium rarely causes allergic reactions.
An MRI can last anywhere from 15 minutes to more than an hour. You must be still because the movement can blur the MRI images.
During a functional MRI, you might be asked to perform a number of small tasks — such as tapping your thumb against your fingers, rubbing a block of sandpaper or answering simple questions. This helps pinpoint the portions of your brain that control these actions.
If you haven't been sedated, you can resume your general activities immediately after the MRI scan.
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