<s>
Medical	B-Algorithm
imaging	I-Algorithm
in	I-Algorithm
pregnancy	I-Algorithm
may	O
be	O
indicated	O
because	O
of	O
pregnancy	O
complications	O
,	O
intercurrent	O
diseases	O
or	O
routine	O
prenatal	O
care	O
.	O
</s>
<s>
Options	O
for	O
medical	B-Algorithm
imaging	I-Algorithm
in	I-Algorithm
pregnancy	I-Algorithm
include	O
the	O
following	O
:	O
</s>
<s>
Magnetic	O
resonance	O
imaging	O
(	O
MRI	O
)	O
without	O
MRI	B-Algorithm
contrast	I-Algorithm
agents	I-Algorithm
as	O
well	O
as	O
obstetric	O
ultrasonography	O
are	O
not	O
associated	O
with	O
any	O
risk	O
for	O
the	O
mother	O
or	O
the	O
fetus	O
and	O
are	O
the	O
imaging	O
techniques	O
of	O
choice	O
for	O
pregnant	O
women	O
.	O
</s>
<s>
Radiocontrast	B-Application
agents	I-Application
,	O
when	O
orally	O
administered	O
,	O
are	O
harmless	O
.	O
</s>
<s>
Intravenous	O
administration	O
of	O
iodinated	O
radiocontrast	B-Application
agents	I-Application
can	O
cross	O
the	O
placenta	O
and	O
enter	O
the	O
fetal	O
circulation	O
,	O
but	O
animal	O
studies	O
have	O
reported	O
no	O
teratogenic	O
or	O
mutagenic	O
effects	O
from	O
its	O
use	O
.	O
</s>
<s>
Nevertheless	O
,	O
it	O
generally	O
is	O
recommended	O
that	O
radiocontrast	B-Application
only	O
be	O
used	O
if	O
required	O
to	O
obtain	O
additional	O
diagnostic	O
information	O
that	O
will	O
improve	O
the	O
care	O
of	O
the	O
fetus	O
or	O
mother	O
.	O
</s>
<s>
Magnetic	O
resonance	O
imaging	O
(	O
MRI	O
)	O
,	O
without	O
MRI	B-Algorithm
contrast	I-Algorithm
agents	I-Algorithm
,	O
is	O
not	O
associated	O
with	O
any	O
risk	O
for	O
the	O
mother	O
or	O
the	O
fetus	O
,	O
and	O
together	O
with	O
medical	B-Application
ultrasonography	I-Application
,	O
it	O
is	O
the	O
technique	O
of	O
choice	O
for	O
medical	B-Algorithm
imaging	I-Algorithm
in	I-Algorithm
pregnancy	I-Algorithm
.	O
</s>
<s>
This	O
is	O
an	O
important	O
factor	O
when	O
for	O
example	O
determining	O
whether	O
a	O
ventilation/perfusion	B-Algorithm
scan	I-Algorithm
(	O
V/Q	B-Algorithm
scan	I-Algorithm
)	O
or	O
a	O
CT	B-Algorithm
pulmonary	I-Algorithm
angiogram	I-Algorithm
(	O
CTPA	B-Algorithm
)	O
is	O
the	O
optimal	O
investigation	O
in	O
pregnant	O
women	O
with	O
suspected	O
pulmonary	O
embolism	O
.	O
</s>
<s>
A	O
V/Q	B-Algorithm
scan	I-Algorithm
confers	O
a	O
higher	O
radiation	O
dose	O
to	O
the	O
fetus	O
,	O
while	O
a	O
CTPA	B-Algorithm
confers	O
a	O
much	O
higher	O
radiation	O
dose	O
to	O
the	O
mother	O
's	O
breasts	O
.	O
</s>
<s>
A	O
review	O
from	O
the	O
United	O
Kingdom	O
in	O
2005	O
considered	O
CTPA	B-Algorithm
to	O
be	O
generally	O
preferable	O
in	O
suspected	O
pulmonary	O
embolism	O
in	O
pregnancy	O
because	O
of	O
higher	O
sensitivity	O
and	O
specificity	O
as	O
well	O
as	O
a	O
relatively	O
modest	O
cost	O
.	O
</s>
