MGH Martinos Center for Biomedical Imaging 2017 | Page 17

intervention, Greve says. “Prior to
FreeSurfer, these structures would
have to be manually designated—a
tedious and error-prone process.
Using FreeSurfer, we can quantify
these changes automatically, which
allows reliable studies with large
sample sizes to be possible.”
A Brief History of Surfing the Brain
The origins of FreeSurfer can be
traced to PhD dissertation work by
Anders Dale, done in the early 1990s
under the supervision of Marty
Sereno at the University of Califor-
nia, San Diego. Dale wrote the initial
software code while trying to tackle
the EEG/MEG inverse problem—
essentially the problem of trying
to glean information about the
brain from electromagnetic signals
recorded outside the skull—and in
doing so enable reconstruction of
the brain’s surface with EEG/MEG.
Others had sought ways to model
the surface of the brain, to essen-
tially flatten the organ for visualiza-
tion and analysis purposes; Sereno
himself had literally flattened a
brain some years before, in the
mid-1980s, seeking insight into how
to achieve this. The breakthrough
in Dale’s work came when he and
Sereno realized they could infer the
outlines of the pial surface—that is,
the “top” of the gray matter, where
adjacent banks of a sulcus are too
close to one another to be resolved
by MRI—by imaging its “bottom,”
the boundary between the gray and
white matter.
Bruce Fischl introduces Doug Greve at the FreeSurfer Symposium. Photo by
Caroline Magnain.
completing a fellowship at UCSD,
Dale in 1996 joined what is now
the MGH Martinos Center for
Biomedical Imaging, where he con-
tinued a collaboration with Roger
Tootell’s group, applying the code he
had written in looking at the visual
cortex with the nascent imaging
technique functional MRI.
Not long after, in January of 1997,
the Center welcomed researcher
Bruce Fischl, a one-time software
developer working in industry and
a recent PhD graduate in Cogni-
tive and Neural Systems. In a series
of conversations in the following
months, Fischl and Dale huddled
together to discuss the potential for
Dale’s code; especially with greater
numbers of researchers adopting
functional MRI, they knew, there
would be a strong need for accurate
anatomical guidance. They decided
to join forces to develop the code for
broader use in the neurosciences.
Today, FreeSurfer
boasts nearly 33,000
active licenses, with
users around the world
applying the software
to a wide range of basic
science and clinical
problems
The researchers set to work, col-
The next stage in the software’s laborating with Sereno back in San
history kicked off in 1996. After Diego in seeking ways to improve
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