<s>
Signal	B-Algorithm
enhancement	I-Algorithm
by	I-Algorithm
extravascular	I-Algorithm
water	I-Algorithm
protons	I-Algorithm
,	O
or	O
SEEP	O
,	O
is	O
a	O
contrast	O
mechanism	O
for	O
functional	B-Algorithm
magnetic	I-Algorithm
resonance	I-Algorithm
imaging	I-Algorithm
(	O
fMRI	B-Algorithm
)	O
,	O
which	O
is	O
an	O
alternative	O
to	O
the	O
more	O
commonly	O
employed	O
BOLD	O
(	O
blood-oxygen-level	B-Algorithm
dependent	I-Algorithm
)	O
contrast	O
.	O
</s>
<s>
Such	O
susceptibility	O
differences	O
can	O
give	O
rise	O
to	O
spatial	O
image	O
distortions	O
and	O
areas	O
of	O
low	O
signal	O
,	O
and	O
magnetic	O
susceptibility	O
changes	O
in	O
blood	O
give	O
rise	O
to	O
the	O
BOLD	O
contrast	O
for	O
fMRI	B-Algorithm
.	O
</s>
<s>
The	O
primary	O
application	O
of	O
SEEP	O
to	O
date	O
has	O
been	O
fMRI	B-Algorithm
of	O
the	O
spinal	O
cord	O
(	O
spinal	B-Algorithm
fMRI	I-Algorithm
)	O
because	O
the	O
bone/tissue	O
interfaces	O
around	O
the	O
spinal	O
cord	O
cause	O
poor	O
image	O
quality	O
with	O
conventional	O
fMRI	B-Algorithm
methods	O
.	O
</s>
<s>
SEEP	O
is	O
controversial	O
because	O
it	O
is	O
not	O
universally	O
agreed	O
to	O
exist	O
as	O
a	O
contrast	O
mechanism	O
for	O
fMRI	B-Algorithm
.	O
</s>
