<s>
Vaginal	B-Algorithm
ultrasonography	I-Algorithm
is	O
a	O
medical	B-Application
ultrasonography	I-Application
that	O
applies	O
an	O
ultrasound	O
transducer	O
(	O
or	O
"	O
probe	O
"	O
)	O
in	O
the	O
vagina	O
to	O
visualize	O
organs	O
within	O
the	O
pelvic	O
cavity	O
.	O
</s>
<s>
It	O
is	O
also	O
called	O
transvaginal	B-Algorithm
ultrasonography	I-Algorithm
because	O
the	O
ultrasound	O
waves	O
go	O
across	O
the	O
vaginal	O
wall	O
to	O
study	O
tissues	O
beyond	O
it	O
.	O
</s>
<s>
Vaginal	B-Algorithm
ultrasonography	I-Algorithm
is	O
used	O
both	O
as	O
a	O
means	O
of	O
gynecologic	O
ultrasonography	O
and	O
obstetric	O
ultrasonography	O
.	O
</s>
<s>
It	O
is	O
preferred	O
over	O
abdominal	B-Algorithm
ultrasonography	I-Algorithm
in	O
the	O
diagnosis	O
of	O
ectopic	O
pregnancy	O
.	O
</s>
