<s>
Voxel-based	B-Algorithm
morphometry	I-Algorithm
is	O
a	O
computational	O
approach	O
to	O
neuroanatomy	O
that	O
measures	O
differences	O
in	O
local	O
concentrations	O
of	O
brain	O
tissue	O
,	O
through	O
a	O
voxel-wise	O
comparison	O
of	O
multiple	O
brain	O
images	O
.	O
</s>
<s>
In	O
traditional	O
morphometry	O
,	O
volume	O
of	O
the	O
whole	O
brain	O
or	O
its	O
subparts	O
is	O
measured	O
by	O
drawing	O
regions	O
of	O
interest	O
(	O
ROIs	O
)	O
on	O
images	O
from	O
brain	B-Algorithm
scanning	I-Algorithm
and	O
calculating	O
the	O
volume	O
enclosed	O
.	O
</s>
<s>
VBM	O
registers	B-Algorithm
every	O
brain	O
to	O
a	O
template	O
,	O
which	O
gets	O
rid	O
of	O
most	O
of	O
the	O
large	O
differences	O
in	O
brain	O
anatomy	O
among	O
people	O
.	O
</s>
<s>
Then	O
the	O
brain	O
images	O
are	O
smoothed	O
so	O
that	O
each	O
voxel	B-Algorithm
represents	O
the	O
average	O
of	O
itself	O
and	O
its	O
neighbors	O
.	O
</s>
<s>
Finally	O
,	O
the	O
image	O
volume	O
is	O
compared	O
across	O
brains	O
at	O
every	O
voxel	B-Algorithm
.	O
</s>
<s>
Many	O
of	O
these	O
studies	O
were	O
performed	O
using	O
voxel-based	B-Algorithm
morphometry	I-Algorithm
(	O
VBM	O
)	O
,	O
a	O
whole-brain	O
technique	O
for	O
characterizing	O
between	O
groups	O
 '	O
regional	O
volume	O
and	O
tissue	O
concentration	O
differences	O
from	O
structural	O
magnetic	O
resonance	O
imaging	O
(	O
MRI	O
)	O
scans	O
.	O
</s>
<s>
A	O
key	O
description	O
of	O
the	O
methodology	O
of	O
voxel-based	B-Algorithm
morphometry	I-Algorithm
is	O
Voxel-Based	B-Algorithm
Morphometry	I-Algorithm
—	O
The	O
Methodsone	O
of	O
the	O
most	O
cited	O
articles	O
in	O
the	O
journal	O
NeuroImage	O
.	O
</s>
<s>
The	O
usual	O
approach	O
for	O
statistical	O
analysis	O
is	O
mass-univariate	O
(	O
analysis	O
of	O
each	O
voxel	B-Algorithm
separately	O
)	O
,	O
but	O
pattern	O
recognition	O
may	O
also	O
be	O
used	O
,	O
e.g.	O
,	O
for	O
classifying	O
patients	O
from	O
healthy	O
.	O
</s>
<s>
Construction	O
of	O
white	O
and	O
grey	O
matter	O
templates	O
from	O
segmentation	B-Algorithm
.	O
</s>
<s>
Segmentation	B-Algorithm
and	O
extraction	O
of	O
brain	O
image	O
,	O
e.g.	O
,	O
removal	O
of	O
scalp	O
tissue	O
in	O
the	O
image	O
.	O
</s>
<s>
Spatial	O
smoothing	O
(	O
intensity	O
in	O
each	O
voxel	B-Algorithm
is	O
a	O
local	O
weighted	O
average	O
generally	O
expressed	O
as	O
GM	O
,	O
WM	O
,	O
CSF	O
concentration	O
)	O
.	O
</s>
<s>
The	O
outcome	O
of	O
these	O
steps	O
is	O
a	O
statistical	O
parametric	O
map	O
,	O
highlighting	O
all	O
voxels	B-Algorithm
of	O
the	O
brain	O
where	O
intensities	O
(	O
volume	O
or	O
GM	O
concentration	O
depending	O
on	O
whether	O
the	O
modulation	O
step	O
has	O
been	O
applied	O
or	O
not	O
)	O
in	O
a	O
group	O
images	O
are	O
significantly	O
lower/higher	O
than	O
those	O
in	O
the	O
other	O
group	O
under	O
investigation	O
.	O
</s>
<s>
However	O
,	O
compared	O
to	O
the	O
region	O
of	O
interest	O
approach	O
,	O
VBM	O
presents	O
a	O
large	O
number	O
of	O
advantages	O
that	O
explain	O
its	O
wide	O
popularity	O
within	O
the	O
neuroimaging	B-Algorithm
community	O
.	O
</s>
