Pitfalls and Practical Challenges in Sonographic Imaging of the Uterus

Uncommon Entities in Uterine Imaging

Let's look at some uncommon entities.

This is a patient who came at 25 weeks of gestation for left upper quadrant pain.

What do you think when you see this image?

How about this image?

We see a foot in a sack, a fluid-filled sack in the left upper quadrant, two feet.

Here's some bones. We know this is the foot, this is the uterus.

This is a uterine rupture.

Here's the MRI image of the fetus in the uterus with the feet protruding through the ruptured uterus into an intact amniotic sack.

Here's the transverse image.

We see a little debris in the sac protruding.

We see the fetus is relatively confined because a lot of the fluid is pushed out into the extra uterine amniotic sac.

Here's the bones and the limbs.

Portions of the limbs protruding through this large defect, relatively large defect.

And then on the sagittal image, we see it protruding a little superiorly.

Here's the defect. We even have a three dimensional image of the feet protruding quite a shocking image, so an uncommon challenge may be uterine rupture.

This was chronic uterine rupture with intact amnion.

Patient History

This patient had a prior missed abortion at 15 weeks with subsequent DNE after the DNE.

She had subsequent persistent bleeding and hysteroscopy in which they removed.

Placenta pathology showed that this was actually a fallopian tubal segment, so she must have had a prior perforation at the initial DNE and the fallopian tube ended up partially protruding into the endometrium.

She underwent a subsequent laparoscopic repair and it was unclear if this was cauterized or stitched the defect.

And then she got pregnant within a year with IVF.

So she had a reason to have a rupture on this side.

She had prior surgery and complication and probable rupture at A DNE.

Clinical Course and Outcome

This patient had no cord prolapse at 25 weeks on the MRI only the feet were prolapsing.

She was admitted. She was tokenized with magnesium and then the cord prolapsed in the next week.

Follow-up ultrasounds were performed daily for umbilical artery doppler monitoring.

She presented then with abdominal pain at 30 weeks gestation in which she was discovered to have rupture of membranes and was precipitously delivered with a classical C-section.

The infant's legs were slightly swollen at delivery.

This spontaneously resolved and there was a good outcome for both the patient and the fetus.

Here we see the cord prolapsing Around the limb and we monitored with the umbilical artery doppler until her membrane's ruptured.

Incidence and Characteristics of Uterine Rupture

So uterine rupture is about 0.05% has an incidence of about 0.05% during pregnancy.

It's usually through a prior C-section scar greater than 90%.

It may be limited to dehiscence of the ends of the scar with intact overlying cirr rosa.

It may be full thickness rupture with direct communication of the uterus and peritoneal cavities.

Full thickness rupture carries a high fetal and maternal morbidity and mortality and classical scars are prone to rupture prior to labor, whereas lower uterine scars are prone to rupture after labor.

Presentation

What is the presentation?

Abdominal pain, as we saw here, of abdominal discomfort and hemodynamic instability.

Imaging Features

The imaging features are some of which we saw here, protruding portion of sac or contents, endometrial or myometrial defect, which we did eventually see an extra uterine hematoma we didn't see.

And hemoperitoneum or free fluid, which we only saw after the membranes ruptured.

Bandl's Ring Case

This is a different case. This is a case at 22 weeks.

Gestation was in labor and delivery for termination by induction due to a severe Chiari two malformation.

I was called for an MRI because the patient failed to progress with laminaria and cytotech, an ultrasound, which we don't have recorded images.

The uterus was dilated in the lower portion, but the cervix wouldn't open.

And at the time they wondered if there was a focal rupture or if it had possibly been misdiagnosed as an abdominal pregnancy.

Here we see a transverse image on MRI.

Here's the Lamin area.

In the relatively horizontal appearing uterus, this is a fully catheter in the urinary bladder.

On serial longitudinal images, we see that there is a dilated lower uterus.

Here's the fetus confined in the upper uterus, there is myometrium around here and there is a cervical canal.

We see a portion of the Lamin area on transverse imaging.

We see the placenta anterior, we see the fetus pushing against this constricting region and we see the membrane of the meningocele.

So what is, what would you think of if you see a fetus with this type of configuration of the uterus?

With induction of labor, we went back retrospectively and looked and we had actually imaged this patient in the second trimester.

Here we see a cervix. Here we see the lower uterus.

There's no constriction here either on the longitudinal or the transverse.

Here's the right and nal region, the left and nal region in the lower uterus.

And there's no such constriction deformity.

So what are we thinking? This can't be a signia.

It wasn't present prior to labor induction.

What is something that can present like this that can happen with labor induction?

This is a band's ring.

This is a pathologic retraction ring at Barnes boundary line.

It's a constriction at the junction of the thin lower uterus with the thick retracted upper uterine segment.

It results in obstructed labor.

It's one precursor to circulation and ruptured uterus.

This patient was then delivered by C-section hysterectomy.

So here we see the contraction, the constriction deformity at the Barnes boundary line and it forces the lower uterus into the pelvis and there is inadequate pressure on the cervix to open.

So there's just a fluid filled sack above the cervix and the fetus can't get to the internal loss to push the cervix open.

And we also see the dilated ventricles of the Chiari Chiari malformation.

Differentiating from Uterine Incarceration

So uncommon entities in challenges of imaging, the uterus are rupture and bands ring.

Now I ask you, why is this not a uterine incarceration?

What is different about uterine incarceration than this image here and uterine incarceration?

Portions of the uterus can be confined in the deep felt pelvis.

But what is different about this picture here is the bladder with a Foley.

This is was a little bit of free fluid around this uterus.

This is the same my meningocele patient. This is the cervix.

So what is different about the position of the uterus or the cervix in a patient with band's ring versus uterine incarceration?

Here's the cervix.

Here's a normally oriented cervix.

So the cervix is within the pelvis and is plexed.

It can be mildly plexed as we see here, or more plexed as we saw in this prior case of the band's ring.

Case Example

What about this case? This is a case borrowed from Dr. Hertz Herzberg's group. Here is the lower uterine segment.

Here is the fetal head. This is the cervix.

This cervix is displaced superiorly and anteriorly to the fetal head.

So we're thinking, could this be rupture?

Could this be a duplicated uterus with another uterus next to it?

MRI can be very helpful if the, if you have no prior ultrasound and no prior documentation of what the fetus and the uterus looked like previously on MRI, we see this is the efface uterus anterior to the rest of the efface cervix anterior to the rest of the uterus.

And on transverse imaging we see the cervix anterior to the uterus.

Uterine Incarceration

So this is a patient who presented in the second trimester with persistent pelvic pain.

This is a classic picture of uterine incarceration.

It's entrapment of a portion of the uterus and displacement of the cervix such that the fetus can never get out early in the first trimester.

This is a non gravid uterus, but patients who have retro positioned uterus are prone to uterine incarceration.

And you can imagine that as the a gestational sac would en enlarge this fundal uterus, it comes more superiorly and can get stuck at the sacral promontory.

If it doesn't pop out, it may spontaneously correct and pop out.

If it doesn't pop out, you can result in long-term uterine incarceration.

If it occurs in the first trimester, it's usually associated with transient urinary retention because the cervix is then pushed anteriorly and it's hard for the detrusor muscles to work because there is mass effect on the urinary bladder.

Rarely a portion of the uterus can be entrapped in the uterus between the sacral promontory and the pubic synthesis.

Long term, the symptoms can be vague, diffuse pain, urinary retention, or even incontinence.

Here we see another, a beautiful diagram also by Herzberg Herzberg's group to clearly delineate what is going on here.

Here's a portion of the uterus that is stuck between the sacral promontory and the synthesis.

It never popped out and corrected.

The cervix is pulled up anteriorly in a face and here is the vagina.

So you can see why this would result in pain.

And also there's pressure as the fetus grows and the uterus enlarges upon the urinary bladder and so the patient can have urinary symptoms.

Predisposing Factors

Predisposing factors are not only a retro positioned uterus prior to pregnancy, but pelvic masses, posterior or fungal fibroids can trap portions of the uterus.

Endometriosis can create adhesions that can prevent the uterus from moving normally.

And uterine structural abnormalities are also associated with uterine.

Diagnostic Features

What do we look for? One is difficulty finding the cervix because it's anterior and superiorly displaced relative to the trapped grave, uterus or uterine segment.

There may be coexisting mullar and duct anomalies which may predispose or simulate incarceration, and it may result in sation, which is functional malformation of the grave uterus where there's a transitory pouch or sac in the posterior pelvis caused by the inverted uterine polarity.

Here the uterine wall can become thinned in its prone to rupture.

Pitfalls and Practical Challenges in Sonographic Imaging

So in pitfalls and practical challenges and sonographic imaging of the uterus, I encourage you to try to recall the characteristic sonographic features of both the common and uncommon entities and don't be afraid to utilize three-dimensional ultrasound and MRI to help you come to a more complete diagnosis to spare the patient any catastrophic outcomes.

Thank you for your attention.