Magnetic Resonance Imaging (MRI Scan)


How does an MRI Scanner Work?

The biggest and most important component in an MRI system is the magnet.  The MRI machine has a horizontal tube running through the magnet from front to back. This tube is known as the bore of the magnet. The patient, lying on his or her back, slides into the bore on a special table. Whether or not the patient goes in head first or feet first, as well as how far in the magnet they will go, is determined by the type of exam to be performed. Once the body part to be scanned is in the exact center or isocenter of the magnetic field, the scan can begin.

In conjunction with radio wave pulses of energy, an MRI scanner can pick out a very small point inside the patient's body and ask it, essentially, "What type of tissue are you?" The point might be a cube that is half a millimetre on each side. The MRI system goes through the patient's body point by point, building up a 2-D or 3-D map of tissue types. It then integrates all of this information together to create 2-D images or 3-D models. The image below shows an MRI of the abdomen.

MRI of abdomen

MRI provides an unparalleled view inside the human body. The level of detail that can be seen is extraordinary compared with any other imaging modality. MRI is the method of choice for the diagnosis of many types of injuries and conditions because of the ability to tailor the exam to the particular "medical question" being asked.

Background Information about MRI at Lakes DHB

In 2004, Lakes DHB established an MRI scanner on site at Rotorua Hospital as one of its top short-term priorities. A business plan was accordingly drawn up.

A generous donation from Rotorua Energy Charitable Trust (Rotorua Trust) allowed Lakes DHB to purchase and install this essential piece of modern diagnostic equipment. For more information on Rotorua Trust, access their website on

Below is a photograph of the MRI magnet arriving at Rotorua Hospital in May 2005. The new service commenced from 1 July 2005.

Key Documents

Click here for a copy of the 'Information for Magnetic Resonance Imaging' pamphlet, which is made available to all patients undergoing this diagnostic procedure.

Click here for a copy of the Lakes DHB MRI referral form.

Contact the Team

For further information, or queries regarding MRI, telephone the Radiology Department on (07) 349 7906, or click here to e-mail the MRI team.

11/06/2014 8:56 a.m.
Carly Malcolm