Magnetic Resonance Imaging

GE 3T MRI AT Pretoria East Hospital

Drs. Koen and Symington recently installed the new, state-of-art 3T Magnetic Resonance Imaging (MRI) scanner, from GE Healthcare, at the Pretoria East hospital. This high definition system provides access to today's comprehensive range of clinical applications with industry leading reconstruction and processing speeds. The industry unique, 3rd generation 3T magnet is designed to deliver outstanding performance today and for the future.


This MRI machine uses a strong magnet and radiowaves to make images of the body interior. The scanning procedure is very much like an x-ray CT scan. You will be asked to lie on a long narrow couch for a certain amount of time (20 - 30 minutes) while the machine gathers data. During this time you will not be exposed to x-rays, but rather a magnetic field and radiowaves. You will not feel either. You will, however, hear repetitive tapping noises that arise from the radio antenna around your body. We will provide earplugs or ear phones that you will be required to wear. The space within the large magnet in which you lie is somewhat confined, although we have taken many steps to relieve the “claustrophobic” feeling.

There are no known significant risks with this procedure at this time because the radiowaves and magnetic fields, at the strengths used, are thought to be without harm. The exception is if you have a cardiac pacemaker, or a certain type of metallic clip in your body (i.e., an aneurysm clip in your brain). There is a possibility that you will experience a localized twitching sensation due to the magnetic field changes during the scan. This is not unexpected and should not be painful. However, you can discontinue the exam at anytime.

The magnetism and radiowaves do not cause harmful effects at the levels used in the MRI machine. However, because the MR scanner uses a very strong magnet that will attract metal, all metallic objects and coins must be removed from your person before you approach the scanner. In addition, watches and credit cards should also be removed as these could be damaged. (These items will be locked away).


If you have any history of head or eye injury involving metal fragments, if you have ever worked in a metal shop or been a soldier, or if you have some type of implanted electrical device (such as a cardiac pacemaker), if you have severe heart disease (including susceptibility to arrhythmias), if you are wearing metal braces on your teeth, or (for women) if you could be pregnant, especially in the 1st three months of pregnancy, this should be discussed with the Radiologist and the referring doctor. Sometimes this may preclude you from having an immediate MRI, depending on the clinical situation.

If you wish, we can prescribe a mild sedative to help you to relax during the scan session. Because you may still feel sleepy after taking this medication, you should not plan on driving yourself after the MRI, as this may be dangerous.