MRI is a clinical imaging method employing a strong magnet and radiofrequency pulses to image different structures in the body. All molecules within the body contain a small inherent magnetic property. These will respond differently in different magnetic fields. It is this characteristic which is used in MR imaging. Radiofrequency waves are then also employed to adjust the reaction of the molecules to the magnetic field and this is measured by the scanner to produce an image. MRI has superior contrast resolution in soft tissues and is excellent in evaluating the brain and neural structures, but also for the musculoskeletal system and soft tissue organs. Motion does limit MR evaluation, as sequences take relatively long and the patient and organs studied need to remain perfectly still. Newer techniques and equipment are however continuously decreasing imaging times.

Magnetic fields used by commercial MRI scanners most commonly range between 1.5 and 3 Tesla. (A fridge magnet is approx 4 milli Tesla). The patient will however not be aware of the magnetic field at all, providing that he/she has removed all metal objects. In some cases a MRI may be contra-indicated if the patient has a pacemaker or certain older metal implants. No radiation is used and the side-effects are minimal. The patient usually lies supine within the scanner and needs to remain still for between 20 - 40 minutes. In certain cases sedation or anaesthesia  may be required to achieve this. In some cases intravenous gadolinium contrast may be given for specific evaluations. MRI gives exquisite anatomical detail, but can also provide some physiological information, especially regarding water molecule motion which is of value in diagnosing early stroke, as well as tumour evaluation and follow-up.

Currently we perform MRI scans at our St Anne's and Hilton branches.

Specific MRI studies:

  • MR Brain
  • MR spine
  • MRCP
  • MR Rectum
  • MR prostate
  • Breast MRI
  • MR Liver
  • MR angiography
  • Musculoskeletal MR

Please see www.radiologyinfo.org for more information on radiological studies.