MRI (Magnetic Resonance Imaging) - An MRI scanner passes a magnetic field through a person's body and this causes a type of vibration (resonance). As a result an image of their body and problems with it are produced. It is a painless, safe imaging system (which involves no radiation exposure) and there are no harmful effects ever recorded of this procedure. Advanced computer technology can enhance the images produced, e.g. show them in 3D colour.