<s>
Blood	B-Algorithm
pool	I-Algorithm
agents	I-Algorithm
(	O
BPAs	O
)	O
are	O
a	O
class	O
of	O
magnetic	B-Algorithm
resonance	I-Algorithm
angiography	I-Algorithm
contrast	B-Algorithm
agents	I-Algorithm
.	O
</s>
<s>
Blood	B-Algorithm
pool	I-Algorithm
agents	I-Algorithm
(	O
also	O
known	O
as	O
intravascular	O
contrast	B-Algorithm
agents	I-Algorithm
)	O
are	O
differentiated	O
from	O
other	O
contrast	B-Algorithm
agents	I-Algorithm
due	O
to	O
their	O
high	O
molecular	O
weight	O
and	O
higher	O
relaxivities	B-Algorithm
.	O
</s>
<s>
Most	O
contrast	B-Algorithm
agents	I-Algorithm
,	O
leave	O
the	O
vascular	O
system	O
within	O
a	O
few	O
minutes	O
,	O
however	O
blood	B-Algorithm
pool	I-Algorithm
agents	I-Algorithm
remain	O
in	O
the	O
circulation	O
for	O
up	O
to	O
an	O
hour	O
,	O
extending	O
the	O
window	O
available	O
for	O
imaging	O
.	O
</s>
<s>
Due	O
to	O
their	O
extended	O
time	O
in	O
the	O
circulatory	O
system	O
,	O
blood	B-Algorithm
pool	I-Algorithm
agents	I-Algorithm
can	O
be	O
used	O
for	O
delayed	O
steady-state	O
imaging	O
,	O
and	O
additionally	O
these	O
results	O
can	O
be	O
combined	O
with	O
first	O
pass	O
arterial	O
imaging	O
.	O
</s>
<s>
Gadobenic	O
acid	O
(	O
MultiHance®	O
)	O
is	O
sometimes	O
categorized	O
as	O
a	O
BPA	O
;	O
however	O
,	O
as	O
it	O
only	O
binds	O
weakly	O
to	O
albumin	O
and	O
because	O
hepatobiliary	O
uptake	O
of	O
this	O
compound	O
occurs	O
,	O
this	O
contrast	B-Algorithm
agent	I-Algorithm
should	O
not	O
be	O
classified	O
as	O
a	O
BPA	O
.	O
</s>
