MGH Martinos Center for Biomedical Imaging 2017 | Page 25

Each of the scans takes only a few
moments. With the noninvasive
technology they are using—near-
infrared spectroscopy / diffuse
correlation
spectroscopy—mea-
surements involve little more than
briefly, gently pressing a probe
against the head; this system was
designed so parents themselves can
hold the probe in place, helping to
keep the children calm and comfort-
able during the measurements. Over
the course of the next eight days, the
scientists will scan 485 children in
six different villages.
Introduced some 20 years ago, near-
infrared spectroscopy (NIRS) can
determine the amount of oxygen in
the bloo d, non-invasively, by trans-
mitting laser light into the body and
detecting the light as it emerges. A
more recent development, diffuse
correlation spectroscopy (DCS)
adds measures of blood flow to
the optical monitoring toolbox.
Together, the two techniques have
made it possible to calculate the
cerebral metabolic rate of oxygen
(CMRO2)—an established marker
hand market stalls in Guinea-Bissau. of brain maturation—relatively
A young girl appears wearing an easily with a small piece of hardware
irrepressible smile and a Minnie and a laptop computer.
Mouse top.
Franceschini has taken full advan-
It feels almost festive. When the tage of this opportunity. Over the
scientists arrived in the village, past decade, she has worked on
earlier today, many of the children the cutting edge of developing and
and their parents came out to greet applying combined NIRS-DCS for
them, laughing and smiling and the study of brain development in
embracing them. Even now, the area newborns and infants. Her work has
around the schoolhouse is abuzz yielded a number of new insights,
with conversation. A few of the kids and these in turn have pointed to
are playing with inflatable balls the possible interventions in the care
scientists brought with them.
of infants. Today, she is also col-
laborating with clinicians at MGH
and elsewhere, seeking to establish
NIRS-DCS as a tool to guide and
optimize individual care.
The technique works for global
health applications for the same
reasons it works for bedside moni-
toring in the clinical environment:
It is a noninvasive and portable
technology, user friendly while also
robust. The Guinea-Bissau measure-
ments, performed over the course of
the three visits, demonstrated the
feasibility of using the technology
in remote, resource-poor regions,
where portable generators provide
the only electricity and the average
temperatures hover in the 100
degree range. For all its advantages
elsewhere, MRI wouldn’t work
here. Nor would most other brain
imaging techniques. NIRS-DCS is,
simply, the right tool to get the job
done.
In addition to validating the tech-
nology for this and other, similar
global health applications, the pilot
study in Guinea-Bissau yielded
some important early findings—
showing that children who perform
poorly on cognitive testing also have
lower-than-average measures of
cerebral blood flow. Ultimately, the
neuroimaging tool could allow the
researchers to compare brain matu-
ration before and after the nutrition
intervention, to help determine
the impact of the intervention on
cognitive and neurodevelopmental
outcomes.
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