On the day of your MRI scan, you should be able to eat, drink and take any medication as usual, unless you're advised otherwise. In some cases, you may be asked not to eat or drink anything for up to 4 hours before the scan, and sometimes you may be asked to drink a fairly large amount of water beforehand.
Since the MRI machines are magnets, it is best to not apply deodorants, antiperspirants, perfumes, or body lotions before the examination. These items contain metals that might interfere with the magnetic field inside the MRI machine and cause you to have distorted images and wrong results.
No preparation is necessary for an MRI scan. You can eat and drink normally. Though some discomfort may occur from having to lay still, MRI is otherwise a painless procedure. A MRI scan typically takes approximately 20 to 30 minutes to perform.
If you are getting intravenous contrast material, which helps your body part show up better in the MRI pictures, or sedative medicine during the examination, you may be asked to not eat solid food for four to eight hours before the examination.
Prior to Your Appointment
Do not drink or eat anything with caffeine for 24 hours before the MRI, as caffeine may affect the results. This includes coffee, tea, soda, and chocolate. Do not eat for four hours before the MRI.
You will be asked to fast for 4 hours prior to your exam. You may take your usual medications with small amounts of water. Otherwise, no additional preparation is needed.
Unless you're told otherwise, you can shower and wash your hair the morning of your MRI. Don't use any hair products (such as hair spray or hair gel). Don't wear any metal objects. Remove all jewelry, including body piercings.
Can a subject wear deodorant for an MRI scan? It is recommended to refrain from wearing any powder, perfumes, deodorant and/or lotions on your underarms and chest area prior to the procedure. This is to prevent the possibility of localized burns because these items may have metal in them.
After the scan, you can resume normal activities immediately. But if you have had a sedative, a friend or relative will need to take you home and stay with you for the first 24 hours. It's not safe to drive, operate heavy machinery or drink alcohol for 24 hours after having a sedative.
How long does an MRI scan take? A single scan may take a few seconds or 3 to 8 minutes. You may be asked to hold your breath during short scans. The total scan lasts 15 to 90 minutes, depending on the size of the area being scanned and how many images are needed.
For women, if possible, do not wear an underwire bra (the metal can throw off the magnetic field). Sports bras are usually good and we have hospital gowns to change into if necessary. The clasps on the back of a regular bra are not a problem, but avoid wearing bras that have metal parts on the straps.
The magnetic fields that change with time create loud knocking noises which may harm hearing if adequate ear protection is not used. They may also cause peripheral muscle or nerve stimulation that may feel like a twitching sensation. The radiofrequency energy used during the MRI scan could lead to heating of the body.
You will be asked to remove any clothing containing metal and all jewelry. You will be provided metal free clothing to change into such as gown, shorts or pants. Lockers are available to safely store all personal items such as wallet, purse, keys, phone and other electronic devices.
Embedded bullets, BB's, shrapnel, shotgun pellets or metal filings. Pins or plates in or on your bones, including metallic joint. Body piercings, jewelry, metal on or in clothing. Medical devices with magnets, such as a cochlear implant or chest expanders.
If you are having an MRI scan that does not require you to follow commands, you may be allowed to fall asleep. You should clarify this with your radiologist before the procedure begins.
If you need to cough or get an itch, tell them and they can get you out, or give you a short break between sequences. Then you are moved out of the machine, released, have your plastic tube removed and can go home.
Magnets only attract ferromagnetic metals such as iron, cobalt, and nickel. Metal fillings, commonly called silver fillings because of their color, are made of about 50% mercury, plus silver, tin, copper, and other metals. Magnets have no effect on these materials.
Be sure to wear clothing that does not have any metal in it (zippers, buttons, etc.). If your clothes do have metal in them, you'll be given a hospital gown to change into for your scan. Normally you can wear your underwear and socks during the scan, unless your radiologist is concerned about metal microfibers.
No other preparation is required, except for the cardiac stress perfusion MRI where you will be asked to avoid caffeine for 24–48 hours before the test. Caffeine interferes with the action of adenosine (see Stress Perfusion MRI above), which is used to simulate the stress part of this MRI scan.
There aren't any side-effects from the MRI scan itself. However, if you've had an injection of contrast medium (dye) as part of the investigation, you may have some side-effects which might include a skin rash, dizziness, a headache, and nausea.
It is likely that you will experience cramping, wind-like discomfort and some diarrhoea for the first 24 hours after the scan. This is caused by the Mannitol drink, and is very common affecting 1 in 10 people. If this happens to you, you may wish to take some pain relief, and drink water to keep hydrated.
Radiologists recommend fasting prior to undergoing a CT or MRI with contrast because of the possible side effects of the contrast agents. While rare, side effects of contrast can cause nausea or vomiting during the test. Vomiting while lying down could cause food blockages in your airway, known as asphyxia.
Before an MRI exam, eat normally and continue to take your usual medications, unless otherwise instructed. You will typically be asked to change into a gown and to remove things that might affect the magnetic imaging, such as: Jewelry. Hairpins.