STATE-OF-THE-ART MRI SCAN WATCHES THE BRAIN AT WORK
UIC physicians can now watch the brain at work, thanks to the medical center's newly installed very-high-field magnetic resonance imaging (MRI) scanner, a state-of-the-art machine that reveals not only anatomical detail but metabolic activity as well.
At present the only one of its kind in the Chicago area, the device for evaluating brain functions-called functional imaging-has a multitude of applications in medical practice and research. It enables clinicians to plan for safer outcomes in neurological surgery and monitor rehabilitation therapies after stroke and head injury, and it allows scientists to map cognitive abilities in an effort to understand degenerative diseases like Parkinson's and Alzheimer's.
In its first application, UIC's advanced MRI scanner was used to map speech areas in the brain of a patient expected to undergo surgery for a brain tumor. Guided by data from the scanner, the surgeons will be able to avoid damaging those critical areas and causing debilitating symptoms when the tumor is excised.
"This is leading-edge technology giving us an advanced tool for both patient care and medical research," said Keith Thulborn, director of MRI research, chief of cross-sectional neuroradiology and professor of radiology, physiology and biophysics. Thulborn, who joined UIC in July, was recruited to head the university's Center of MR Research and turn it into a world-class establishment. Known internationally for his development of high-field MRI, Thulborn has pursued a lifelong interest in the workings of the human brain.
The very-high-field MRI scanner, built by General Electric Medical Systems, is housed in a new, top-of-the-line facility at the UIC Medical Center. Researchers at the center are just steps away from clinicians, fostering an unusually close-knit collaboration for developing innovative approaches to medical problems.
The scanner works by picking up faint magnetic signals in the underlying tissue. As neurons become increasingly active in specific regions of the brain, blood flow surges to those regions and blood volume expands.
In the process, deoxygenated blood is replaced with oxygenated blood, the two differing in their magnetic properties. The MRI scanner is able to detect this magnetic change, although minute, because of the scanner's high magnetic field strength: 3.0 Tesla, twice that of MRI scanners more commonly deployed in clinical settings. (A Tesla is equivalent to 10,000 gauss; the magnetic field strength of Earth is less than one gauss). Cross-sectional images are made through the entire brain to create a three-dimensional view. The images must be run through a series of statistical programs so that they can be correctly interpreted.
To obtain images of the working brain, patients are placed on a table and moved into the center of the magnet. The images are taken while patients are engaged in a set of cognitive tasks devised to correlate functional activities with specific areas of the brain. To map the language comprehension network of the brain, for example, patients are given sentences of varying complexity to read and asked to answer true/false questions by pressing a finger switch. To map the motor and sensory areas, patients simply tap a finger.
Functional imaging of the brain with the 3.0-Tesla scanner is expected to enable neurologists, neurosurgeons and psychiatrists at UIC to, among other things,
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