So what is an ectopic pregnancy?
That is a pregnancy that's located outside of the normal uterine cavity
and usually these results in a tubal location.
This can actually rupture and cause life threatening hemorrhage
so these are very important to identify early on
and patients usually present with lower abdominal pain
in the case of an ectopic pregnancy.
So let's look at some imaging findings.
Ectopic pregnancies are usually presented as a heterogeneous adnexal mass
and we'll look at some of these in detail.
You can have a tubal ring sign.
You can have what's called as pseudogestational sacs,
you can actually have a sac within the uterus
but it's not a true gestational sac.
One finding which is very commonly seen
especially in early pregnancy is really just no identifiable pregnancy
so in a patient that comes in with a positive beta HCG level
knowing they are pregnant and we don't see any pregnancy identified anywhere,
this is actually very common finding in ectopic pregnancy.
The patient may also present with a large amount of hemorrhagic fluid
which can happen in the case of a ruptured ectopic pregnancy.
So let's go into a little more detail with some of this.
So the tubal ring sign is actually an echogenic ring
that separates the ectopic pregnancy from the ovary.
Occasionally, you can actually see an entire yolk sac and embryo
as an ectopic pregnancy but often all you see is a mass like lesion.
A pseudogestational sac as I've mentioned
is actually a cystic intrauterine structure which appears to be a gestational sac
but doesn't contain any embryo.
It has a surrounding thickened echogenic endometrium
or a decidual reaction as we saw earlier.
So this can be as somewhat misleading and it's important to see
that even if you have what appears to be a gestational sac
within the uterus you wanna make sure
that you don't actually have another mass outside
that could represent an ectopic pregnancy.
So this is an example of an ultrasound demonstrating an ectopic pregnancy
in the right adnexum. So you have a pregnant patient
that comes in with lower abdominal pain.
We have a sagittal image of the uterus here
which doesn't show any kind of gestational sac.
On the image of the right ovary, we see a normal looking ovary here
and then we have what appears to be an echogenic mass adjacent
to the right ovary and this actually represents an ectopic pregnancy.
So again, no evidence of an intrauterine pregnancy in a patient
that has a positive beta HCG level and a gestational age
that represents about 7 weeks.
So at 7 weeks, we really should be seeing an embryo
and possibly even a fetal heart rate.
So there are multiple locations of ectopic pregnancy.
Again, the most common is the tubal location as we mentioned right here,
however, they can be interstitial
which is right at the entrance of the fallopian tube into the uterus.
They can be cervical or down in the cervix
and they can be at the distal end of the tube or in the fimbrial.
So multiple different locations and all of these really need to be evaluated
for any kind of solid mass when performing an ultrasound
looking for an ectopic pregnancy.
Ectopic pregnancies can rupture
and they can result in very life threatening hemorrhage
so it's important to recognize these early.
So how are ectopic pregnancy is treated
if you do see an ectopic pregnancy on ultrasound?
The first step is to call an OB-GYNE physician.
They can be treated medically with Methotrexate.
In this case the patient has to be stable,
there can be no evidence of rupture of the ectopic,
and this is usually about 90% effective in early,
unruptured small ectopic pregnancies.
However, in a patient that doesn't meet those requirements
the option is surgical treatment and this is really the only option available
for a patient that has a ruptured ectopic pregnancy
in which case they remove the fallopian tube
especially the segment of the tube located at the level of the ectopic pregnancy
and they try to reconnect the tube to preserve fertility
if possible although occasionally that really isn't possible.
Another option is to do a salphingotomy
or just an incision in the tube to remove the ectopic pregnancy
and then again put the tube back together again.
The third option is actually ultrasound guided injection
so Methotrexate or a potassium chloride can be injected into the gestational sac
using ultrasound guidance.