Magnetic resonance imaging (MRI)

Magnetic resonance imaging (MRI)

MRI is a medical imaging technique that uses magnetic fields and radio waves to construct detailed images of the body. MRI machines are usually long and tube-shaped, with moving platform that you lie face-up on as you pass through the scanner. As with CT scanning, you may be required to take an oral/intravenous contrast agent that improves the detail of the images -this is called magnetic resonance enterography, or MRE for short.

An MRI has the benefit of not relying on radiation exposure, unlike X-ray, CT scanning, or DEXA scanning. This means that MRI is suitable in situations where a person may need to be scanned many times. MRI also allows your doctor to view the entire small bowel. This is very useful as inflammation can occur in sections of the small bowel (e.g., jejunum), that are challenging to access with other methods of examination.

You will need to fast before the procedure and will also need to remove items that can interfere with the magnetic fields (e.g., jewellery, glasses, watches). You may also then be asked to take an oral contrasting agent, which comes as a large drink. Patients then lie flat on a moving table that slides into the machine. The scanning process can take anywhere from 15 minutes to an hour or more. The machine can be noisy at times, this is normal and due to the machine producing the rapid electrical pulses needed to generate the magnetic field.

Things to note:

  • It is essential you follow the instructions given to you with regard to avoiding food/drink prior to the scan. This is to ensure the accuracy of the scan.
  • MRI may be unsuitable for people with pacemakers or other internal metal/electronic devices.