Ultrasound for Non-Obstetrical Acute Abdomen Pain in Pregnancy - SD

Introduction

Hello, I'm Dr. John McGann.
I'm from the University of California Davis Medical Center,
which is located in Sacramento, California.
Today I'm gonna talk to you about a problematic area,
which is how do we diagnose etiologies of pain in the pregnant patients
that are non obstetrical causes of pain.
I'm gonna talk to you today about ultrasound
and non obstetrical acute abdominal pain.
So I'm not gonna talk about OB GYN causes,
but all other causes of pain.

Common Causes of Pain in Pregnancy

If we look at common causes of pain in pregnancy,
this is basically the list.
There's one thing I haven't included,
which is more common cause of pain in pregnancy
that we don't think about, and that's trauma overall.
If we look at this list overall, there's about
pain in pregnancy, non-traumatic one in 500 pregnancies.

Imaging Choices and Radiation Concerns

What are imaging choices?
Ultrasound, MRI and ct,
but as you know, we're trying to get away from radiation.
So CT is not looked upon as favorably, especially
during pregnancy.
We look at this slide and it basically cts outta control
or my cat's outta control here, ct, whether it's 20%
or 30% of the examinations,
and it produces 70 to 80% of radiation dose
from medical use in the United States.
Here's a study from Brow University
and the number of pregnant women scan with CT increased
by almost 90% in 10 years
and yet only 7% increase in admission.
So there's no doubt that CTUs, even in pregnant women
to this point, has been increasing.

Radiation Risks in Pregnancy

Now I have to go back to our physics a little bit
and basically we know
that if you go ahead in the first trimester
and have a 10 milli vert level for radiation
to an embryo, there may be anatomical defects.
But in fact, if you're at about the two
to three milli vert level, which you are with a single slide
or a single CT through the pelvis, you can actually
increase the risk of childhood leukemia.
Nobody really knows what that is
'cause there is a latent effect here of up to 20 years.
But it is thought there's increased risk
of leukemia in childhood from fetal
or embryonic dose due to CT as such.
We wanna limit that.
Even the late press,
this is from USA today from an article in the New England
Journal of Medicine and they again talk about CTL scanners
and say in a few decades, 2%
of all cancers in the US may be due to radiation from ct.
So what do they recommend? A lot of different things.
One of the things they say, what about ultrasound
or MRI, which I'm gonna talk to you about two principles.
First principle, do no harm in most situations, ultrasound
probably should be the initial exam of choice.
Second, establish the diagnosis.
When you have to utilizing MI CT
or whatever, you have to really think about both the health
of the mother and the fetus.

Trauma in Pregnancy

Well, one thing I didn't list was trauma
and that's really the most common etiology
of pain in the abdomen in pregnant patients.
How do we manage that with a trauma fast scan?
And a lot of times people don't think about the fast scan.
If in fact we want to, we may even have cts
to the upper abdomen only to minimize radiation dose
to the pelvis, especially during that first trimester trauma
and pregnancy due to a number of cause.
But certainly MVAs assaults are high on that list.
We looked at this
and published our results in radiology in 2004
and basically out of a number of different exams,
over 2000 we ended up with 23 with a intraabdominal
injuries in patients that were pregnant.
We basically checked free fluid organ for abnormalities
and looked at the pregnancy as well.
Sensitivity in the first trimester was very good.
It was 90% sensitivity in the second
and third trimester was very poor.
And it's very surprising why it was poor.
It wasn't because we missed splenic lesions
or we missed liver lesions.
It was because of abrupt placenta.
If you put in the six cases
of abrupt show into our overall statistics,
our overall sensitivity would've been 88%.

Examples of Trauma Cases

I'm gonna give a few examples here.
And these are all pregnant women.
So if you see fluid even in the cul-de-sac in these pregnant
women, it may mean something.
And this was a lady who had free fluid in the cul-de-sac.
We went ahead and today a limited ct, no operation
and she had a splenic lac.
Here's another case,
however, a 30-year-old woman,
first trimester free fluid in the right upper
quadrant of the abdomen.
We also identified free fluid along the flanks
and both anterior posterior to the uterus.
That patient was taken directly to the operating room without a ct, a similar patient
and a 22-year-old with free fluid again anterior to the bladder as well as free fluid adjacent to the spleen.
And the spleen was very, very difficult to identify.
She had a splenic lack
and was taken directly to the OR without a ct.

Abruption Placenta

Here is the most common misdiagnosis to surprise
and chagrin was this type of a case
and sometimes it is much more subtle.
Unfortunately this is not a subtle case,
but this is a case of abruption placenta
and what are the findings, why I did a study years ago
and basically in about 50% in the cases we don't see a lot
and I think that's really problematic in these cases.
You look for a big hematoma, either intra placental
or retro placental clot adjacent
to the placenta thicken placenta.
And on a rare case you would see an intra amniotic debris
or an amniotic fluid hemorrhage level.

Contrast Enhanced Sonography in Trauma

Well, what could be the future here?
Well just think if we could use contrast enhanced sonography
in blood abdominal trauma.
No need to do ct,
however, it's not only not approved in pregnancy
but not even approved in the US for abdominal use except
through IRBs.
But here's a study we did a couple years ago.
Here's a splenic lac.
Here's what it looked like on the ultrasound.
Without contrast, it was interpreted as normal.
And here's the image that you can see.
With ultrasound contrast.
You can very nicely see the very echogenic spleen with
contrast and the hypo coic laceration.
We identified all splenic lacerations in our study.
Here's another case in which you see a very complex splenic
laceration and here is the ultrasound image with contrast.
Again, you can see this is a very complex injury
with multiple hypo coic areas through there corresponding to
multiple small splenic lacerations.
In fact, I actually think ultrasound better depicts the
injury than CT does in this case.

Non-Traumatic Etiologies: Appendicitis

Other potential etiologies.
So non-traumatic etiologies always appendicitis is
at the top of the list.
Suspected appendicitis, we try with ultrasound
but eventually may have to go with MR
and we try to avoid ct.
Why do we have such a problem with ultrasound?
Well, couple different things during pregnancy,
the enlarging uterus may go ahead and push the cecum
or the appendix up
or probably even more problematic is the uterus itself may
overly the appendix.
We may never be able to really see the appendix
with ultrasound.
What do we look for? Same things we look
for in the non-pregnant patients.
So non-compressible blind ending tubular structure
greater than six millimeters in diameter
with an app pinnacle lift and mesentary stranding sometimes
and free fluid, sometimes ultrasound technique.
I use a curve transducer, not really initially first
for the appendix but for other things
'cause we really don't know the etiology of the pain.
Is it ovarian torsion? Is it a renal problem?
A gallbladder problem?
Once I do really focus on the appendix,
I use a curver linear
or a linear array for the right lower quadrant I do a compression technique
and then I ask the patient where their specific side
of a tenderness is and I may go ahead
and do in vaginal especially for the first trimester.
Another thing that I do,
and this is not a pregnant female, this is a male model here, but I push very firm
and then I sometimes put my hand behind the patient
and scan upward from there.
This is a case here in which we're scanning it
through the bowel
and you can see an echogenic focus with some shadowing.
You may see an app pinnacle lift,
but this is compressible, this is the seum in this case
here is another case
and you can see a very small appendix, not that large.
We really had problems with this.
This is at six millimeters,
but you note here there's a little free fluid
in this case.
And then we go ahead and you can see that
and you see this small amount of free fluid.
Then the longitudinal, you can go ahead
and see, it's a blind ending.
Tubular structure, not that large
but a little free fluid at the tip.
And this ended up being very early acute appendicitis.
This would be a very problematic case
'cause it measured six to eight millimeters
depending on where you measured it.
Here's a more common example. 29-year-old postpartum.
Now with right lower quadrant pain ultrasound, very helpful.
So you can see some of this increased mesentary,
guy haziness or edema in there.
And then you see the blind ending fluid field tubular
structure corresponding to acute appendicitis.
However, if we look at statistics here,
ultrasounds certainly is not as sensitive for MRI
for looking at acute appendicitis.
Sensitivity and ultrasound in this series was only 36%
compared to the sensitivity
for MRI which was a hundred percent.

MRI for Appendicitis

How do we do our MRI
and basically we want to use some
mildly T two weighted image such as a single shot fasp
and echo if using ge, which corresponds
to a hay sequence on semen express and picker et cetera.
So there's all sorts of different acronyms used for that.
And then we'll also throw in some sort of a fast T one image as well.
Now can we use gadolinium?
Really we can't use gadolinium
and use only if essential in pregnancy,
especially in the first trimester
'cause it is shown to have teratogenic effects
in pregnant rabbits.
If we look at different classifications, a drug
by the FDAA category B drug would be iodinated
contrast or Tylenol.
We could use those. But a class C drug is
where there is adverse effects on fetuses that we in animals but we really don't know in humans.
So that would be IV contrast for ct. This is B gadolinium.
We should not use this during pregnancy.
Again, just like ultrasound
for entertainment MRI gives us such gorgeous pictures.
We really should not do this for entertainment
but should be done for a strict indication.
Well what does the normal appendix look like
on the single shot?
Fast and echos ti corresponds to the terminal ileum.
You can see here the low intensity appendix.
Another shot here, low intensity appendix right there
and then a coronal reformatted image again
showing the appendix.
What do we really look for?
And I really look for those T two weighted images
for increased signal intensity in the lumen
where the fluid is and then surrounded the appendix only
slight increased signal intensity in the wall.
Here's an example from the literature showing acute appendicitis.
Here you can see that.
And now you can see in this image here,
you see the acute appendicitis,
which is posterior to the uterus.
You see how the wall is thickened, there's fluid within the lumen and there's some surrounding of fluid as well.
Now I use this to show you the normal appendix in this case
and normal appendix compared to the other side
of the abnormal appendix.
And you can see the marked difference, sort
of the dark appearance of the normal appendix
and then with the T two weighted images,
the increased signal intensity.
Here's a case where there is an app pinnacle lift alone
to me by Fergus Coley in in acute appendicitis.
So you see that dark append lift in this case
but there is fluid within that appendix.
And this is a case of acute appendicitis.
Another case that we had in which we went back
and forth, there is some uncertainty here
because this appendix, as you see here, there's free fluid,
but as they measured out it measured
about eight millimeters.
There was some uncertainty.
So what I did, I said I will look exactly there.
So we had a localizer already.
So I looked first at the gallbladder,
then I looked at the kidney again not jumping
to the conclusion this was acute appendicitis.
And then later I found this blind ending tubular structure.
You see a little fluid here
and you see it transfers measuring it nearly a centimeter.
And you can see the correlation between MRI
and the ultrasound in this case.
And then this is the real time image
and I think that real time image really shows you
that blind ending tubular structure which is fluid filled
surrounded by fluid with the diagnosis,
which was acute appendicitis, which required appendectomy.

Acute Cholecystitis

Next etiology
of pain I'm gonna look at is acute cholecystitis.
And what happens in pregnancy?
Well you get progesterone and estrogen.
One causes relaxation in the smooth muscle
leads to bile stasis.
The other causes formation of gallstones.
So what you end up with in these cases is stones,
or in this case the rolling stones.
So you have to look for these, they're increase,
but many times you don't even have to have stone disease.
In this case such as this patient who was on TPN
had sludge fill,
gallbladder had acute right upper quadrant pain,
positive ultrasound murphy's,
she had a calculus cholecystitis
that required cholecystectomy.
Another case here in which there is fulminant
acute cholecystitis.
So there was CSIS sludge.
There was also thickened gallbladder wall
and peric cystic fluid as well
as a positive ultrasound murphy sign In this case.
How do you manage these patients mostly medically if you can
laparoscopic cholecystectomy
and only rarely would we ever do a chole cystostomy.
However, back in 1992 we described the first case which we
manage using chole cystostomy.
And basically this patient carried pregnancy
and tube for another 10 weeks and delivered
and then had an elective cholecystectomy.
She was very, very sick.
A patient who could not go on to elective cholecystectomy
during her pregnancy.
This will show you the case here.
As we go ahead, we see the gallbladder, we see the
ultrasound, trocar, needle placement here.
Once we're in there we slide the catheter off the trocar
up placed.
Then after we're in there we aspirate the bile
and this is where color flow may be used
to aspirate the bile
and show us that we're in the gallbladder
with the aggressive fluid.
We get increased color flow through that catheter.
MRI may be helpful, probably not so much
for acute cholecystitis
but for complications of csis such
as biliary ductal obstruction.
This is a normal example here.
This is a 2D MRI
CP using a fairly thick slice about six centimeters
and it only takes us five seconds.
We can do wagon wheel that takes a bunch of slices.
That'll take, its less than a minute
or we can do 3D that'll take us a little longer.
But you can see very nicely here the common bile duct.
And you can see the rest of the biliary system.
You can see the gallbladder,
you can even identify the pancreatic duct.
You can see I can miss very small stones,
but you can certainly say in this case there is no evidence
of biliary ductal dilatation.
You can see very nicely the pregnancy here as well.

Pyelonephritis and Obstruction

Pyelonephritis and obstruction.
Again, ultrasound probably is the key here.
And most of these don't come to imaging
and really they're image only if there's an
unresolved event.
'cause plon nephritis is probably more common
than stones.
Again, when we do these with ultrasound,
the kidneys transabdominal
and then transvaginal allure, ureters,
and then in severe pain if they think there is a stone,
a stent may be placed under ultrasound guidance.
Again, first the curved array, transducer
and then endo vaginal in the first trimester if we're lucky,
such as in this case, which is very, very rare,
we're able to see the stone.
I'd say this would not be our typical example.
This would be a case in which we're very lucky.
We see there's high nephrosis and a stone as well.
We described where we could go ahead
and do percutaneous nephrostomy.
We have done this in a number of cases in which
the patient is very, very sick
and we've done a number of different things in
pregnant patients including a nephrostomy.
Here's another case
of a 14 week pregnancy in which they elected
to do a stent from above.
This is the stone that you can see right there.
And this is the stent, no fluoro at all.
And we are asked to stand by
as they put a stent from the bladder up into
that hydro nephrotic kidney passed the stone ultrasound completely without any
fluoroscopy, therefore no radiation to
that 14 week fetus.
Another very interesting case here,
right upper quadrant pain.
And we looked at the ultrasound, he necrosis,
but is that he necrosis a pregnancy or is that real?
Then we looked at the left kidney normal
and you look here, there's he necrosis,
but there's also fluid around that kidney.
Now how did we really make the diagnosis?
Well, first we did an MRI
and we saw there's a jet on the left side.
Then we did ultrasound and I waited
and I scanned myself for five minutes.
Jet on the left side, nothing on the right side at all.
This is just the real time clip.
So when you think about this as a simple test show,
a complete obstruction in this case.
So the seeing the lack
of Jad on the right side demonstrated there was high
nephrosis due to a stone.
Very interesting case.
It was later on in pregnancy and this was the left kidney.
And you can see something very echogenic here.
And these were the dilated CAEs here
and they're full of something here.
And this turned out the postpartum CT
and mr, you can see a stone here again,
what we saw in ultrasound.
This turned out to be XPG.
She was delivered virtually at 37 weeks when we discover this.
But look at how really nice the ultrasound correlates
with the ct.
So this is the pre-delivery ultrasound
and the post-delivery reconstructed a ct.
You can see how nice they are
and they almost look exactly the same here.
Her again, mrm, RU
or MRM urography can be used.
But again, we can't use gadolinium problem right here.
As you can see as we get down more distally,
if there's a stone here, we may miss it.
'cause now we've tried to cut out some of
that pregnant uterus
and in doing so, we're sort
of overlapping the distal ureter here
so we can see if there's he nephrosis,
but we may not always be able to tell the etiology here.
Again, no gadolinium is used.
When we have renal obstruction,
we get in decreased renal blood flow,
increased interstitial fibrosis and again damage.
That's why we want this to be treated.
A lot has been talked in the past about use
of resistive index in renal obstruction.
Recent article came out in the JUM really said it's
insensitive and quite controversial
and I would think in pregnancy had probably
be very insensitive.
I found no specific studies in pregnancy.
You have sort of the normal hydronephrosis
of pregnancy versus the stones.
They may occur there. I think it would be very difficult.
Another thing with MRI is we have the apparent effusion
coefficient or the A DC, which is actually made up
of both diffusion and perfusion.
And it ends up you can subtract the
per
or the diffusion portion from the A DC
and get the pure perfu perfusion fraction.
With that, you can actually see if there is
decreased blood flow.
So this is the regular A DC in which there was obstruction
on this side compared to the others,
which I took from radiology here.
And you can see it if in fact you did the perfusion
fraction only you can see there's decreased perfusion on the
right of the obstructed as compared
to the left hand side.
Currently, this is really only a research technique
and I don't think it's really been put in
the clinical practice.
And if necessary, if we can't figure it out, we have
to go on to look at CT
and we can decrease the CT dose here.
So we're looking at 1.5 milli seavers instead
of three milli seavers.
But again, you get a hydro nephrotic kidney and the stone.

Other Etiologies: Bowel Obstruction and PAD Rupture

A couple of final things.
Bowel obstruction, ultrasound really plays
no role whatsoever.
Again, adhesions are the most common.
MRI may be very helpful.
This is a example of a small bowel obstruction on the left
and another small bowel obstruction with MRI on the right.
Again, ultrasound plays really probably not a major role.
And then a pad rupture may be related to pregnancy
or may not be related to pregnancy such as trauma.
In trauma. This is a great example of a pad laceration.
Here you can see the echogenic clot as well
as the free fluid and the hypo coic area within the liver in trauma.
However, there's the help syndrome,
which is hemolytic anemia, elevated liver enzymes,
and low platelet count in which you can also have problems
in the liver.
And in these it's more
of a hepatic infarction rather than any sort of laceration.
So you get an unusual pattern.
It's really a hypoperfusion area.
You get peripheral model hypo intense
lesions throughout the liver.
Eventually you can get hemorrhage and
or hepatic laceration or rupture.

Conclusion

So I've sort of taking you through step
by step all these different etiologies
for acute pain and pregnancy.
And I've not gone ahead and talked about any of the OB
or GYN causes, but taking you through trauma
and all the others, again,
almost in all these ultrasounds should be first
and then you can go ahead and try MRI or CT if needed.
I think that's probably, with a few exceptions,
maybe a pad rupture, bowel obstruction.
MRI or CT may have to be used in these cases.
Again, what we're trying to do is do no harm
to either the fetus.
And in these cases ultrasound should be used,
especially in the first trimester.
However, if we have to
and we really have to think about the optimal care
of both the mother and the fetus, we may have to go ahead
and use CT in these cases so we can end up with this at the end of the road.
Thank you.