What is MRI?

During Brain Awareness Week we’ll be delving into the human mind as part of our ‘Mind Reading?’ event. We will use Magnetic Resonance Imaging (MRI) to do this, a technology which has revolutionised medicine. So how does this amazing machine work?

 MRI is now used all over the world to peer inside patients to create pictures of incredible quality, and to diagnose the problems that are causing their symptoms. It all started about 60 years ago and the journey has included Nobel prizes, dramatic technical developments and the creation of something that was once only a dream.

 MRI uses an extremely strong magnetic field to take its pictures, and while we usually use it to see the anatomy of the brain, the spinal cord and joints like the knee, at our Mind Reading event we’ll be using MRI to journey into the functioning mind.

 Despite the obvious need to be careful with the magnetic field, MRI scanning is considered to be entirely safe. It doesn’t require the use of X-rays like CT scanning, and has been used to perform millions of scans safely all over the world.

MRI scanners use an extremely strong magnetic field!

 MRI is like a TV in that the machine sends a little signal into the patient, then pauses and listens for the signal that comes out. Scientists use a coil to detect that, which means with brain imaging you need a head coil. In order to get that signal we need a very strong magnetic field. The field is so strong that it can suck metal objects into its grasp, and has surprised many unsuspecting people!

 Another way to describe the process is that your body is made up of water. Inside water is protons and it’s the hydrogen protons that we use to make our images. Protons are like little spinning tops, and when a body goes into the scanner, instead of being randomly aligned they all line up like soldiers in rank. Then we get all the tops to start processing in line then turn off our signal so as they come back to their natural position they emit the signal we read and then make into pictures.

 The reason we get so excited by MRI is its future capabilities. It can peer inside people without touching them and with no known side effects. Not only that, but it can actually image blood moving real time, so giving us a clue to brain activity. So this is the only technology that can do what we’re attempting with our Mind Reading event. Will we be able to tell what someone is thinking?

Mind Reading will be held on Wednesday March 14th at Auckland Museum. You can book tickets now.

Mind Reading will use images taken from a Siemens 3T Skyra scanner.

 By Associate Professor Brett Cowan, Director, CAMRI