Functional MRI

Patients can be referred for specialist MRI scans which the MRI Physics Service will carry out or assist with, or patients may be part of a clinical trial being carried out by the MRI Physics service.

The main area in which MRI Physics is involved is functional MRI.  Functional MRI can produce images of the areas of the brain that are activated whilst subjects carrying out a specific task.  These areas of activation are linked to increased blood flow in those areas of the brain.  They are calculated from images acquired both whilst they are carrying out the task and while they are at rest.  In one such procedure we are trying to determine the area of the brain related to movement.  So to do this they will be asked to tap the fingers of one hand for a period of about 10 seconds, then stay very still for the next 10 seconds, and then tap their fingers again for the next 10 seconds.  This pattern will be repeated five times whilst the subject is being scanned.  It is very important that the head is kept as still as possible throughout the whole scan.

There may be other tasks that subjects may be asked to carry out in the scanner.  For example, to locate the areas of the brain related to language, a word generation task might be used. The whole procedure will be explained fully to the subject, including what you they have to do in the scanner, before they go into the scanner.  The scanning procedure is noisy, but the subject be given headphones, which should reduce the noise to a suitable level.  The subject is told what to do through the intercom system when they are in the scanner.  Some standard MR images will also be acquired before the functional imaging study.  The subject does not need to do anything during this time; they just need to lie very still.

Other types of scanning that the MRI Physics service may get involved with are MR spectroscopy, where information about the chemical composition of the brain is obtained from MRI data, and MR perfusion imaging, which looks at blood flow in the brain.

In the future it is hoped that MRI Physics will become much more actively involved in the Cardiac MRI service, particularly when the new dedicated cardiac MRI scanner is installed.

Last Updated 20/02/2008

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