Why might I not be able to have an MRI scan?

An x-ray image showing someone with a pacemaker

Can I have an MRI scan if I have a pacemaker?

Dr Mike Knapton says:

An MRI scanner uses very strong magnetic fields to create a detailed image of the inside of your body. These magnets may affect any metal implants or fragments in your body – including pacemakers and their wires but also implantable cardioverter defibrillators (ICDs), metal heart valves, brain aneurysm clips, artificial joints and dental fillings.

Most modern pacemakers, and some of these other devices, are MRI compatible, but you should always tell medical staff beforehand if you have a pacemaker or any other device inside your body. If we know about it then we can avoid any risks and ensure it won’t affect the scan quality.

These MRI magnets may affect any metal implants or fragments in your body – including pacemakers

It is usually only older devices that cause a problem, so we check the make and model number. An MRI can also affect the settings of your device, as each one is programmed specifically for your heart. 

You need to remove metal objects like watches, belts and jewellery and wear a hospital gown for the procedure.

CT scans can sometimes be an alternative test, using radiation instead of magnetic fields, so they won’t affect your pacemaker. This scan involves lying on a bed which passes through a doughnut-shaped opening in a CT scanner to create an image of your heart.