What is MRI?

Magnetic resonance imaging (MRI) is an innovative technique that provides images of the body in many different planes. The images generated vary according to the tissues examined and reflect their physical and chemical properties. It is non-invasive and involves no exposure to ionising radiation.

MRI has proved to be unusually rewarding in the detection, localisation, and assessment of extent and character of disease in most parts of the body. In the brain, for example, it has a proven capacity to define some tumours and the plaques of multiple sclerosis provided by no other technique.

Magnetic resonance images differ from those produced by X-Rays: the latter are associated with absorption of X-Ray energy, while MR images are based on proton density and proton relaxation dynamics which cause the tissues to emit a weak radio signal. These signals depend on the physical and chemical properties of the tissue and the timing parameters that the operator sets at the scanner controls.

The process of acquiring magnetic resonance images involves rapidly switching electrical currents and radio waves on and off. This creates a significant amount of noise during the scan. The staff will offer you ear protection and we strongly recommend that you take it.

Generally, a scan takes an average of 30 minutes. However, the exact duration will depend on which area of the body is being examined and whether more than one area is to be scanned.