INDIANAPOLIS - When Lewis and Clark
set out on their bold mission, they relied on the compass and personal observations
to map the vast and uncharted land. Similarly, today's scientists rely on functional
magnetic resonance imaging (fMRI) to explore the largely undiscovered frontier
of the human brain.
MRI is a non-invasive imaging technique,
using a powerful magnetic field and advanced computing, to produce animated
3-D images of the inside of the human body. MRI technology at the Indiana University
School of Medicine allows physicians to better understand how the brain works
by mapping sites of activity, thus allowing them to better diagnose and treat
patients with diseases such a brain cancer, stroke and Parkinson disease.
"The fMRI works on the premise
that when brain cells become active, blood flows to them increases and the MRI
scanner detects biological changes and increased oxygen in the areas,"
said Micheal Phillips, M.D., assistant professor of radiology at the Indiana
University School of Medicine, speaking at the Oct. 30 session of Mini Medical
School. "High resolution images resulting from scans allow us to peel away
bone and tissue and map brain activity in real time.
The fMRI can map and gauge brain
activity to a resolution as small as three millimeters. This is accomplished
through the performance of motor or sensory tasks.
As the body performs a motor task,
such as finger tapping, an fMRI scan illustrates those regions of the brain
activated during the finger-tapping exercise. The resulting image shows a bright
signal in the activated regions of the brain. A stroke victim, for example,
can perform the exercise, thus allowing scientists to determine the extent of
brain damage and how the brain "re-learns" certain functions.
When an fMRI scan is performed,
it's necessary the patient remain still inside the MRI cylinder for a two- to-seven
minute period. It doesn't seem like a long time to wait, but the tight quarters
poses somewhat of a problem for many undergoing a scan.
"It's a difficult environment
and not for claustrophobics," Dr. Phillips said, adding that newer MRI
equipment and technology is making the procedure less uncomfortable for patients.
The fMRI also has revealed some
interesting and highly publicized data at the IU School of Medicine. Dr. Phillips,
along with Joseph Lurito, M.D., Ph.D., assistant professor of radiology, conducted
a study a year ago that demonstrating that men listen only with one side of
their brains while women use both sides. In the study, 10 men and 10 women underwent
the fMRI while listening to a book passage. A majority of men showed exclusive
activity on the left side (temporal) lobe, which is associated with listening
and speech. The majority of women showed activity in the left temporal and right
temporal lobe - the side associated with non-language auditory functions.
"As scientists, we're figuring
out what normal is, and more and more often it seems we're finding that normal
for men may be different than normal for women," Dr. Phillips, jokingly
adding that the information from the study has led to other conclusions more
closer to home.
"My wife reminds me that it
just means that women listen a heck of a lot better than men."
Dr. Phillips' appearance was the
fourth in a six-week series of the fall Mini Medical School. Participants meet
each Tuesday night and hear from IU School of Medicine's leading physicians
and researchers.
Mini Medical School is partly funded with an educational grant from Pfizer. IU Medical Group and Indianapolis radio station WIBC sponsor Mini Medical School, which is offered by the Indiana University School of Medicine Faculty Community Relations Committee through the IUPUI Division of Continuing Studies.
Web Sites and
Interesting Links
IU School of Medicine-Department of Radiology
www.indyrad.iupui.edu/
News release and
Images: Men/Women Brain Imaging Study
www.medicine.indiana.edu/news_releases/archive_00/men_hearing00.html
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October 31, 2001 Media Contact: Joe Stuteville
317-274-7722
jstutevi@iupui.edu