April 1, 2010
A new medical imaging lab in the Maritimes could detect and treat neurological diseases, disorders and injuries earlier by recording the brain in action.
The $5.3-million Laboratory for Clinical Magnetoencephalography (MEG) recently opened at the IWK Health Centre in Halifax, in partnership with NRC and Helsinki-based Elekta Neuromag®, the manufacturer of the real-time MEG brain-mapping instrument.
Using advanced imaging technology, the MEG lab will measure brain activity – in both adults and children – as it is happening as opposed to just receiving a static image of the brain.
With MEG, the brain is seen in action rather than as a still image. The blue dot shows the location of activity in the auditory cortex of a person listening to basic auditory tones.
"I compare it to taking your car in for service," explains Dr. Ryan D'Arcy, a Halifax-based NRC neuroscientist and lead researcher on the MEG project. "A mechanic can pop the hood and look at the engine, or take the car for a spin and find out what's really wrong, which is what we're doing with the brain at the MEG lab."
He says that since neural networks are dynamic and process information so rapidly, brain activity needs to be captured in both space and time.
The new MEG lab will support the development of new diagnostics and treatments, such as new drug therapies for people with epilepsy and imaging methods to assess consciousness in patients with brain injuries, developmental disorders or altered awareness.
"Being able to measure function will lead to much earlier diagnosis and much better treatment for a range of conditions, from stroke and brain tumours to Parkinson's disease and autism," says Dr. Ryan D'Arcy. "MEG will enable us to tackle some subtle and complex conditions, such as changes in attention span."
A non-invasive technique for characterizing the neural activity of the central nervous system, MEG detects the magnetic fields generated by the brain, enabling physicians and scientists to measure its activity in real time. While computed tomography (CT) and magnetic resonance imaging (MRI) can provide structural, anatomical and metabolic information of the brain, MEG measures and delivers precise information on brain function, including touch, speech, vision, hearing and motor skills.
Learn about the the Elekta Neuromag® magnetoencephalography system
The lab is also designed to be patient-friendly. A person sits or lies under what appears to be a large hairdryer. "I've joked that it will be the first technology where kids will look forward to coming in and getting a diagnostic test," says Dr. D'Arcy, who serves as group leader at the NRC Institute for Biodiagnostics in the Atlantic region.
But the MEG instrument does some serious analysis.
Once a person is seated under the helmet, 306 sensors, called super-conducting quantum interference devices (SQUIDs), surround the whole head. The SQUID technology is so sensitive that it can detect magnetic fields 100 million times smaller than the earth's magnetic field. In fact, the instrumentation is so acutely affected by external stimuli that a vehicle two kilometres away could swamp the sensors, so the MEG instrument is housed within a highly sophisticated, magnetically shielded room.
For patients, however, the process is easy. They can take a nap while lying down, or read a book or watch television while sitting. Other people are also allowed in the room, such as parents watching their children undergo a diagnostic test. And, unlike a CT or MRI scan, the MEG instrument can be paused and restarted if, for example, the patient needs to go to the washroom.
The MEG is well suited to pediatric patients.
This feature distinguishes MEG from other brain-imaging devices in Canada, because it allows patients to move, says Dr. D'Arcy, who also helped develop a realistic three-dimensional, touch-sensitive simulation of a patient's brain, called NeuroTouch, which neurosurgeons can use to rehearse brain surgery prior to performing the actual procedure on the patient.
The MEG instrument will significantly augment the functional mapping capabilities of NeuroTouch, and will also be invaluable in conducting complicated studies, especially those involving memory loss.
Typically, when MRI scans are taken of people with Alzheimer's disease or dementia, the patients lose track of time and often stop the procedure, which must run uninterrupted. As a result, the data collected is lost.
But not so in the MEG lab, which will be able to stop and start diagnostic tests at any time without losing the data gathered.
The lab will serve as a cutting-edge complement to the Biomedical Magnetic Resonance Imaging Laboratory—another NRC-IWK collaboration, also located at the IWK Health Centre. It will facilitate the integration of MEG results, which show brain activity, with MRI results on brain physiology.
As well, the MEG lab will serve as an important component of Halifax's growing life-sciences technology cluster and further position the city as an emerging international centre able to apply advanced neuroscience to clinical care.
