MEDALL

MRI (Magnetic Resonance Imaging)

• What is an MRI scan?

  MRI stands for Magnetic Resonance Imaging. An MRI scanner uses a magnetic field and radio waves to build up detailed pictures of various parts of the body from the signals that are sent out from the water molecules in the body. Computer systems help with this but no x-rays are used.

• Why am I having an MRI scan?

  MRI scans are investigations that can be used to help doctors to make a diagnosis or assess the effects of treatment. Your doctor will recommend an MRI scan based on the type of disease you have and the reason for the scan.

• Who can have an MRI scan?

  Your doctor will decide if an MRI scan would be helpful in your case. However, some people aren't able to have this scan, for example if: You have a heart pacemaker.

  • You have a heart pacemaker
  • You have had any of the valves in your heart replaced by metal ones
  • You have aneurysm clips in your brain
  • You have ever done any welding or metal work without wearing goggles, or have ever had metal fragments removed from your eyes

  Please contact the MRI department if you think you may be pregnant. MRI scans may not be advisable in early pregnancy, unless there are special circumstances. The radiographers, who carry out the scan, will ask you some questions. You will also be required to fill in a questionnaire about your health and medical history, and you may be asked to sign a consent form.

• What preparation will I need?

  Usually there is no special preparation for an MRI scan. You may eat and drink normally before and after the scan, unless you have been told otherwise. The only exception is an MRCP(Magnetic resonance cholangio-pancreatography) which may require 4-6 hours of fasting prior to the study.

  An injection of contrast medium (dye) may be given into a vein. This is not always necessary, but can provide the scan with extra information. As with all medication, a very small number of patients may be allergic to contrast medium. Please inform the radiographer if you have any allergies.

  A child under the age of seven will probably require a sedative before the MRI exam. The sedative will be administered at the MRI Center before the scan, so plan to arrive approximately one hour before the child's scheduled appointment. Sedation is often more effective if a child is tired and, in the case of an infant, hungry. If possible, do not let your child nap before the exam, and bring a bottle to feed your infant after sedation. Young children should be kept up late the night prior to the exam and awakened early in the morning on the day of their exam.

• What happens when I come for the scan?

  When you come for your appointment it is advisable to wear clothing without metal fastenings. Alternatively we can provide a hospital gown or pyjamas.

  You will not be allowed to take or wear anything metallic or with magnetic strips into the scan room,. You may wear your spectacles, they will be taken off immediately before your scan. A locker is provided for your valuables. You must give the key to a radiographer or to the person accompanying you, as it is magnetic.

• Who will I see when I have my scan?

  As well as meeting reception staff, you will also meet radiographers who are trained to carry out the scans. You may also see a radiologist (a specialist doctor who is trained to interpret the results and carry out some of the more complex examinations).

• Does the scan hurt?

  No, the scan isn't painful. However, you will have to lie still for up to one hour on a table which is quite hard. You may sometimes be asked not to swallow for some time when the scan is going on.You might also be asked to hold your breath for some special studies. The radiographers will do their best to make you comfortable. If you have any pain or discomfort that could lead to difficulties with the scan, please tell the radiographer before your scan.

• What happens during the scan?

  The scanner produces a variety of loud noises, which are produced by magnetic coils that switch on and off during the scan. These coils measure the signal coming from your body in order to make the images. Because these coils are switched on and off rapidly, they vibrate and cause the noise you hear. Ear defenders or earplugs will help reduce this.

  Although the scanner is open at both ends, some people may find this claustrophobic. If you are worried about this, please speak to the radiographer before you come for your scan. During the scan, the radiographer will be able to see you from the control room and you can talk to each other through an intercom.

  Our new generation state of the art MRI scanner takes quite a short time for most studies and is also wider and less noisier than conventional MR machines. A friend or relative is allowed to accompany you into the MR room during your scan.

• How long will the scan take?

  Scans can take between twenty minutes and an hour. If your scan is going to take longer, you will be told this when your appointment is made.

• What happens afterwards?

  You may leave the department as soon as your scan is finished. You may go to the toilet and eat and drink as usual. There are no side effects to the MRI scan itself.