MGH Martinos Center for Biomedical Imaging 2016 | Page 19

In a series of tests, the functional
maps produced by the new approach
proved highly reproducible while
also capturing variability across
subjects. The researchers validated
these results using invasive mapping
methods in surgical patients.
All of this underscored the technique’s potential for clinical application. Among the procedures that
would benefit from its use is neurosurgical planning: mapping areas
of the brain—areas associated with
language and memory, for example—that surgeons especially want
to avoid. A noninvasive functional
mapping technique such as this,
able to delineate functional areas in
the individual brain, could one day

complement or even replace the invasive pre-surgical functional mapping routines, including cortical
stimulation, currently in use.
Even before then, the technique
could help to improve the pre-surgical planning process. In the relatively near term, said Wang, a research
fellow in the Laboratory for the
Study of the Brain Basis of Individual Differences and first author of
the Nature Neuroscience paper, “we
expect that the non-invasive individualized parcellation might serve
as a prescreen method for invasive
cortical stimulation tests, thus making the invasive procedure more efficient and eventually improving the
outcome of surgery.”

Another possibility: applications related to neurological and psychiatric
disorders. The technique could help
to determine the optimal treatment
targets in individual patients in,
for example, transcranial magnetic
stimulation treatment of depression.
A common target for such treatment
is a point 5 cm anterior to the motor cortex. But because of the variability between individuals’ brains,
a target defined as such could fall
in substantially different functional
networks in different subjects—possibly leading to different therapeutic
effects, Wang said. Selecting a target
using the new technique could improve the efficacy of the treatment.

Researchers have reported a technique for mapping functional brain areas in individual subjects, opening the door
to a range of clinical applications of functional MRI. Using the technique, they delineated the subjects’ brains into 18
different networks. The images here show the variability across subjects—especially in higher-order association areas
like the language network in the frontal lobe—as well as the reproducibility within subjects over time. Image and
photo on opposite page both courtesy of Hesheng Liu.