What is an MRI examination?An MRI scan uses a strong magnetic field and radio waves (not X-rays) to create pictures, on a computer, of tissues, organs and other structures inside your body. The MRI scanner is like a tube about 1.5 metres long, surrounded by a large circular magnet. You lie on a couch which then slides into the scanner. The part of your body being examined is positioned in the middle of the tube (to obtain the best images) and while each ‘picture’ is being taken you will need to keep still, otherwise the scan images may be blurred. The examination is carried out by a radiographer together with a radiologist. During your scan the radiographer can see you via a television screen and you will be given a ‘rubber ball’ to hold, which is an alarm signal to the radiographer that you wish to speak to them.
MRI has been shown to be extremely safe as long as proper safety precautions are taken. In general, the MRI procedure produces no pain and causes no known short-term or long-term tissue damage of any kind.
Preparing for the examination
Metal / MRI safetyMetal objects in or outside your body are attracted to the strong magnet in the scanner, therefore you may not enter the MRI examination room with, for example, a wheelchair, keys or coins. Credit/bank cards with a magnetic chip, hearing aids, mobile phones and watches, are damaged when close to the strong magnet in the
scanner (the magnet is always switched on!) Should you (or your companion) have a pacemaker/defibrillator (ICD), a neurostimulator in the spine, aneurysm clips, dentures/teeth with implanted magnetic fastenings, a bladder stimulator or a permanent insulin pump, then you may not enter the examination room. This also applies to foreign metal objects, such as metal splinters (especially in or near the eyes), shrapnel or bullet wounds and older types of heart valves, aneurysm clips or certain cochlear (ear) implants. You may be required to remove medication patches if they contain metal foil. Usually modern hip and knee replacements are not a problem. We request that you complete the ‘MRI checklist’ and bring it with you to your appointment. Should you have answered any questions with a ‘yes’, we request that you contact the Radiology Department immediately.
How to prepare for the MRI examinationUnless otherwise requested by your specialist, you may continue to take any medications and eat and drink normally. Piercings made of gold or silver may be worn as the magnet doesn’t affect these items. All other items of jewellery and watches are best left at home. Please wear comfortable clothing with separate top and bottoms. Should any clothing contain metal parts (e.g. zips or underwired bras) you will be given a gown
to wear. Please don’t apply hairspray and make-up as they can effect MRI images
and cause some irritation.
MedicationsUsually you can continue to take your medications as prescribed, however your doctor may advise you to temporarily stop taking certain medications. We would advise you to bring your medication passport (available from your pharmacist) or alternatively, make a list of all medications that you are taking at the
time of your scan.
Pregnancy and breast-feedingThere is no evidence to suggest that MRI scans pose a risk during pregnancy. However, as a precaution, scanning is not usually recommended during the first 12 weeks of pregnancy. Contrast agents are not used throughout the whole term of the pregnancy. Should you be or think that you may be pregnant, please contact the Radiology Department. If you are breast-feeding and you are given a contrast agent for your examination, then you are requested to express and throw away the breast milk for 24 hours after the examination.
ClaustrophobiaPeople with severe claustrophobia may be anxious about undergoing an MRI scan. Should you have severe claustrophobia, then please inform your specialist or GP of this as they may prescribe a mild sedative. Even a mild sedative will affect your ability to drive, so please make sure that you make other arrangements
for transportation to the hospital.
Contrast AgentsIt is possible that a contrast agent may be administered during your scan. This is determined by the specialist and radiologist and allows the differences between organs and tissues on an MRI scan to be seen more clearly. To administer the contrast agent the radiographer will insert an cannula/intravenous line and will remove the cannula at the end of the examination. During the examination the radiographer will administer the contrast agent. Usually, this will pose no discomfort however you may experience a cold sensation in the arm or a strange taste in the mouth. These sensations only last a few seconds. Rarely do patients have a reaction to the contrast agents used for MRI scans, but should you have had a reaction in the past, please contact the Radiology Department as the radiologist can in consultation with your specialist, take preventative measures. If you have a reduced kidney function we would also request that you contact the Radiology
DisclaimerIn this leaflet, how the examination is carried out is only a general description of a procedure. It may be that your specialist requests a procedure that may vary from the one described here, as it is not possible to list every variant of the procedures that are carried out. Risks and side-effects are only explained in general terms
and possible complications will be explained by your specialist.
The examinationYou are required to report to the Radiology Department (Route 780) 10 minutes before the time stated on your appointment card or letter, keeping in mind that it’s a 10 minute walk from the main entrance to the Radiology Department. Should you require assistance with mobility, transportation can be arranged at the reception
desk in the main hall.
When you check in at the Radiology Department, your details will be verified and orrected if necessary. Should you have forgotten to bring your ´check list´ then you will be required to fill out a new questionnaire. You will then be directed to the correct waiting area.
The radiographer or assistant will collect you (and your companion) from the waiting area, bring you to a changing room where you (and your companion) will be required to leave all metal objects, telephones, credit-bank cards etc, behind. If necessary an intravenous line will be inserted and the procedure will be explained.
You may direct any questions to the radiographer at any time before or during the preparation for your examination.
When you enter the MRI examination room, you will be required to lie on the scanner table. To detect the tiny radio signals that are emitted from the body, a ´receiving device´ is placed behind or around the area to be examined. You will be given a rubber ball to hold onto during the scan. This is the alarm bell and the radiographer will instruct you as to when you can use it.
The part of your body being examined is placed in the middle of the scanner (an open-ended, cylinder-shaped machine about a metre long). During the examination you will hear different kinds of loud noises (knocking/buzzing) but will be given earplugs or headphones to wear. If you wish you may listen to the radio or a cd. During the examination many images are taken. Some images only take a few seconds to make, others several minutes. Once the noise has stopped, then one set of images have been made. During the making of the images and the time in between, you will be required to lay very still. Once all the images have been made the radiographer will slide you out of the scanner, and if you had a contrast agent, will remove the intravenous line. The whole examination takes on average, around 30 minutes, but in some cases can take up to an hour or longer.
After the procedureFor in-patients, transportation back to the ward will be arranged. For out-patients, an ambulance, transportation to the main entrance or another department will be arranged if required. Taxi services require a declaration from your specialist.
The ResultsThe results of your MRI scan will not be available immediately. A radiologist will interpret the images and report to your specialist. You will receive the results from your specialist at your next appointment.
Cancelling or changing your appointmentIf you are unable to attend, please let us know as soon as possible so that your appointment can be given to another patient. You can call the Radiology Department on weekdays between 08:30-16:45 at (+31)24 361 4529.
Should you wish to cancel your appointment we request that you also inform your specialist.