3D Ultrasound of the Female Pelvis and Early Pregnancy: Tips and Tricks - HD

Introduction

Hi, I'm Sht Rogers.
I'm a radiologist at Einstein Medical Center in Philadelphia, and I'll be talking to you today about 3D ultrasound of the female pelvis and early pregnancy.
I'll be discussing a few tips, tricks, and I'll be showing some exquisite images that we can obtain.
Thank you. I have no disclosures.

Overview of 3D Ultrasound

A quick overview about 3D ultrasound.
Basically we are acquiring a volume of 2D ultrasound images of an area of interest.
It can be any part of the body, but today I'll be focusing on acquiring images of the uterus as well as the nexa.
The acquisition can be a free hand or an automatic acquisition.
The volume data is manipulated at the time of acquisition or it can be manipulated offline after the patient leaves.
Sometimes we do both.
In my practice, typically we send the coronal 2D and 3D images to PAX as well as the coronal 2D syne loop.
At the time of acquisition, it's very important to label things properly so that lesions can be localized accurately, particularly if you have a retroflex or retroverted uterus.
And the amount of time that it takes to do the 3D ultrasound is in the range of 30 seconds to two minutes.
After you do a sagittal sweep of the area of interest, the images will come up in a multiplanar display.
At our institution we use Philips IU 22 and epic systems.
And then we also have a Philips ISP portal.

The Z Technique

So the Z technique is a technique described by Dr. Abu Hamad in which there is a step-by-step process in which to obtain the mid coronal plane of the uterus.
So after the acquisition you'll see a box that is a multier multiplanar display of A 3D volume.
And here we have three orthogonal planes.
The sagittal view is the acquisition series.
Then we have a transverse and a coronal plane over here.
So what you do is the reference point is placed in the mid EMS on the sagittal plane.
Then you use a zero rotation to align the long axis of the EMS with the horizontal.
Then you move your cursor over into the next box into the axial plane and you have the reference point put on the EMS and you rotate it again to make sure that the EMS is horizontal.
At that point, the uterus in plain box C here will be visible in the coronal plane.
And then you apply the Z rotation on panel C to display the uterus in that manner.
And then you can make this image big and also do volume rendered imaging in addition to producing a coronal cene loop of the uterus.
So this technique was presented to a set of radiologists and they learned the technique and improved their time in which to obtain the 3D view of the uterus.

Importance of Orientation Labeling

I mentioned earlier the importance of orientation label.
So here we have an example of a retroverted uterus and there's a left-sided gestational sac.
A 3D coronal image of the uterus shows that the sac is actually appearing on the right side of the screen.
And what happens is when you reconstruct a retroverted uterus, the right and the left can appear opposite if you don't do a rotation in the horizontal plane.
But if you look, we have at least an orientation label here that shows you that the left side of the patient is on the left side of the screen.

Technique Considerations

I wanna make a few points about 3D ultrasound technique.
The quality of the 3D image completely depends on the quality of the 2D acquisition.
If you have poor 2D images, you are going to have even poorer 3D images.
At our institution, we include the fundal contour of the uterus as well as one centimeter beyond the uterine CI on either side.
The coronal reconstruction should ideally include the interstitial portions of the fallopian tubes.
So here is a case where the technologist produced these images and I looked at the reformat and I thought, Hmm, is this endometrial cavity small?
But I had the volume data and I made my own reconstruction.
And on my repeat you can see that the uterine cavities is normal and I'm including the interstitial portions of the fallopian tubes.
I also created a 3D volume rendered image and you can clearly see the normal shape and anatomy of the endometrium.
Can see the normal fundal contour as well as a normal junctional zone has a thin hypoechoic line around the endometrium.

Practice Protocol

So in our practice, which patients undergo 3D ultrasound, well it's our standard protocol that all female pelvis and first trimester pregnancy ultrasounds will undergo 3D ultrasound.
Regardless of indication, the technologist constructs and sends the 2D and 3D coronal views of the uterus and a coronal 2D 2D cine loop to pax.
And the 3D volume data is also sent to the portal for offline processing after a patient leaves.
I find that to be extremely helpful in cases where the technologist may have had trouble obtaining the mid coronal plane or if there are other problems in which I need to go back and figure things out.
And here you can see what's running is a normal coronal 2D cine loop of the uterus.

Limitations of 3D Ultrasound

The limitations of 3D ultrasound include the fact that the technologist is the one who selects and reconstructs images.
When single images are sent to pacs, there's loss of spatial resolution in the coronal plane and actually in any plane that is a reformat.
There's an inability to measure structures when there's a freehand acquisition.
And then there are a variety of artifacts that are accentuated with 3D ultrasound.
In addition, certain uterine are not conducive to 3D reconstruction, especially the markedly enlarged mitus uterine.
Also, you have no control of the phase of a menstrual cycle in which a patient will come to undergo imaging.
The A thin endometrium has shown to decrease the diagnostic ability of the coronal 3D image, particularly when you're trying to figure out the effect of a submucosal fibroid on the endometrium.
It's also hard to get a nice view of the junctional zone when the endometrium is quite thin.

Gynecologic Indications

Some of the gynecologic indications include the Malian duct anomalies, which is very important in patients who have infertility abnormalities of the endometrium and the endometrial cavity.
Adenomyosis fibroid mapping IUD assessment of adnexal lesions and I've also found it helpful in deep pelvic implants.
In endometriosis two studies showed that the coronal view of the uterus added value in 24 to 30% of patients, but it is less likely to be helpful if the 2D imaging is completely normal.
And the most common areas in which the 3D imaging helped was in localization of polyps, fibroids, and uterine anomalies.
In these two studies, my view is that coronal and sagittal reformats of this abdomen and pelvis are routinely performed on all CT scans.
And how often are they helpful if the CT scan is completely normal?
Well I think that maybe the coronal view of the uterus is not always helpful, but I think you're not always sure in which cases it will be beneficial and it's important to be able to have that extra information if you need it.

Mullerian Duct Anomalies

This is a diagram from the fertility and sterility or organization and it shows the various malian duct anomalies.
Malian duct anomalies are common in women who have infertility issues and particularly repeated spontaneous miscarriages.
And 3D ultrasound has a very high degree of concordance with MRI in diagnosis of uterine anomalies.
And the most common anomalies that we will see on ultrasound are the septate uterus and its forms and the arcuate uterus 3D ultrasound is very important in delineating the cause of two endometrial cavities on 2D imaging.
So here in this first example we have two uterine cavities and two cerv.
And the 3D ultrasound beautifully demonstrates a delphis uterus.
In this second example, we have two uterine cavities.
Because it is a sub septate uterus,

Endometrial Polyps

It is helpful in showing the extent and location of endometrial polyps.
This is a patient who had a very thickened endometrium containing numerous echogenic endometrial nodules.
A sono histogram shows a carpet of these endometrial polyps throughout the uterus.
And the 3D sono histogram best depicts the extent of these innumerable polyps.
This is a different patient who had one echogenic nodule towards the uterine fundus.
The 3D ultrasound clearly confirms the fundal location just to the right of midline.
A sonohysterogram is not necessary and I believe that these images are really helpful to the gynecologists in localizing focal lesions.

Endometrial Ablation

Endometrial ablation is when the endometrium is ablated to the salus level and it results in a scarred thin ill-defined endometrium in this patient.
Here we have a sagittal view of the uterus showing a ill-defined endometrium.
We don't see the endometrium myometrial junction quite well.
The coronal 2D reformat of the uterus in this patient really shows nicely the degree of endometrial distortion and scarring.
We can appreciate this y shaped uterus.
And I just wanna contrast that here with this normal appearing endometrium.
This is a different patient who underwent an endometrial ablation and presented with pelvic pain and complications are related to bleeding from residual endometrium that's obstructed by the endometrial adhesions in scar tissue.
So this is a sagittal view of the uterus and it shows a thin calcified, a thin endometrium with the calcification and a very ill defined endometrium myometrial junction.
There's a small amount of fluid here in the lower rine segment.
A transverse view showed two focal flute collections in the fundus area of the uterus, but it's the coronal 2D reformat that shows you the location of these flute collections very nicely.
And the patient had bilateral corneal hydrocele pinches as the cause for pain.
Also note we can see the residual endometrium in the midline and contrast that to the normal endometrium.

Adenomyosis

I now wanna talk a little bit about adenomyosis, which is a very, very common gynecological disease and in my practice I describe adenomyosis in a large portion of my pelvic patients.
In this disease the there's migration of the endometrial glands from the basal layer of the endometrium into the myometrium and it is associated with smooth muscle hyperplasia and a variety of ultrasound findings.
The sagittal midline body and fundus of the uterus is most susceptible to adenomyosis due to peristalsis in the corneal fundal raffi which occur in this region.
It occurs here because during menses this is how the uterus helps to clear the blood and also this is how the uterus brings the egg from the fallopian tube into the endometrial cavity.
The corneal fundal area is best appreciated on the coronal 2D and 3D view.
So in this example you can take a look at the thin hypoechoic junctional zone, which outlines the endometrial myometrial junction.
You can see it on both patients here, but we have a disrupted junctional zone in the left fundus, you see how it's very ill-defined.
In addition, we have the endometrial tissue extending upward into the junctional zone resulting in these echogenic striations as well as the myometrial thickening.
And you can see this is occurring in the area of the corneal fundal Raffi.
There are a whole list of different ultrasound findings on 2D imaging that correlate with adenomyosis.
The most specific sign is a myometrial cyst.
The most common sign is myometrial heterogeneity.
This case is showing a small deep sub endometrial cyst as well as ill-defined end endometrial myometrial junction.
This patient also underwent 3D ultrasound imaging and on 3D ultrasound the findings of adenomyosis are disruption and infiltration of the hypoechoic junctional zone by hypoechoic endometrial tissue and also asymmetric thickening of the junctional zone.
A study of 72 patients prior to hysterectomy compared the sensitivity and specificity of 2D and 3D ultrasound in diagnosing adenomyosis.
And what I'd like to point out is that the sensitivity of adenomyosis was higher on 3D ultrasound compared to 2D ultrasound with no change in specificity and in this patient you can appreciate the complete loss of the normal junctional zone and the infiltration of the echogenic endometrial tissue into the junctional zone.
And I like to contrast that with a normal patient.
Adenomyosis can also present as a focal echogenic nodule within the junctional zone.
So in this patient you can see a small echogenic nodule in the left fundus and this patient had two echogenic nodules along the right uterine body and you can see nicely how they're infiltrated into the junctional zone.
And in addition, there is thickening of the junctional zone in the uterine fundus.
3D ultrasound is helpful in clarifying adenomyosis versus fibroids.
So in this patient we have a sagittal view showing echogenic striations and an ill-defined endometrial myometrial junction.
This is a coronal 2D view showing you that there's infiltration into the junctional zone, particularly along the right side of the uterine body and right fundus.
And a little bit in the left there is also a hypoechoic fibroid in the left body that is abutting the endometrium, but it is very well defined and it's different.
It appears different from the adenomyosis.
And the coronal 3D view really shows nicely the changes of adenomyosis and the adjacent fibroid.
And here's the coronal two days, 2D cine loop Showing the same finding.
This is a different patient who has adenomyosis of the right uterine fundus.
We have infiltration of the right junctional zone and myometrial thickening.
And you can see here there's a little bit of mass effect on the endometrium.
And in the left fundus we have a focal fibroid.
We can get the refractory shadowing from the edges and you can see clearly the 3D ultrasound really nicely shows the difference between the two areas.

Fibroids and IUD Placement

This is a patient who had a submucosal fibroid in the right fundus.
You can see the effect on the endometrial cavity.
The patient came to ultrasound however, because while they were putting in an Essure device, they were able to put it on without a problem on the left.
However, they could not put it on the right.
And the reason is the submucosal fibroid was blocking the interstitial portion of the fallopian tube.
And the coronal view of the uterus really shows this nicely.
This is a pediatric patient who came in with pelvic pain.
Her 2D images showed a degenerated fibroid in the right side of the uterus.
You could see that there is a normal endometrial cavity in the midline, but it was very hard to see the relationship of this fibroid to the endometrium on the transverse and sagittal images.
So a coronal 2D view really shows nicely that this submucosal fibroid has a little bit of mass effect from the uterus, but it is not intracavitary and also it is not any form of a uterine anomaly either.
The differential diagnosis would include a hemato mitro in a pediatric patient, but we can exclude that confidently with the ultrasound.
Here is a coronal 2D cine loop.
It clearly shows the relationship of this degenerated fibroid to the endometrium.
And incidentally, she also had an arcuate uterus.
3D imaging is exquisite in delineating the location of intrauterine devices.
On 2D ultrasound, the position may be unclear.
So in this first patient we have a intrauterine device that is completely located within the endometrial canal.
But on the 3D ultrasound we actually see that it is rotated clockwise within the endometrium.
And this is the shadow of the end of the IUD.
In this patient we have an echogenic line on the left side that represents the left arm of the IUD.
The 3D ultrasound shows that the left arm is actually embedded in the myometrium and is not located within the endometrial canal.
These patients will often have increased symptoms compared to patients who have normally positioned IUDs.
This is the third patient who has an IUP and a portion of an IUD is visible within the cervix.
But the coronal 3D image really shows you nicely in one picture, a mal positioned IUD in the cervix as well as a left sided IUPI

Adnexal Evaluation

Use 3D imaging to evaluate the adnexa.
This is a patient who had a tubular cystic structure in the left, a nexa, and we acquired a volume of these area.
We did a 2D reformat and we show a waist sign.
And we also show that there's a continuous lumen of the cystic structure and we were able to confidently say that this is a hydro cell pinks.
We also were able to reformat the images and show nicely the beads on the string sign that correlate with residual endo cell pinal folds and AAL pinks.
The basic point is that you can do a volume sweep and reconstruct the data into any plane that best depicts the findings.
This is a patient who has a retroflex uterus and deep infiltrating end endometriosis on the uterine cirr rosa and the sigmoid cosa.
And this is the 3D image.
It clearly shows this hypoechoic implant very, very nicely.
This is a 3-year-old woman who had two pregnancies and came with pelvic pain and she was diagnosed with pelvic varice.
So these are transverse 2D images showing these serpiginous structures within the left a nexa that had flow on colored doppler.
This is a 2D coronal reformat showing you the extent of the pelvic varice.
And here's a cine loop and it's showing you very nicely how these varis are predominantly on the left side.
And there's a little connection to the right 3D.

Early Pregnancy Applications

Ultrasound of pregnancy implantation in our practice helps us in evaluating angular interstitial and ectopic pregnancies as well as a pregnancy in the setting of a malaria duct anomaly.
So this first patient has an IUP in the right uterine fundal area and we can show clearly on the 3D images that the IUP is completely within the endometrial cavity and it is an intrauterine pregnancy.
This is a different patient on the other side who has a pregnancy on the left side of the uterus and there is a little bulge.
The 3D ultrasound clearly shows that this pregnancy is located within the interstitial portion of the left fallopian tube.
This is an ectopic pregnancy and this is a laparoscopic image of that interstitial pregnancy.
The 3D ultrasound image is diagnostic and the sensitivity of 2D ultrasound is less than perfect.
This is a different patient who has a sack within the cervix and there's a yolk sac on this image.
Within the sac we have a chorionic rim.
In addition, there was a tiny crown rum length with a heartbeat.
The coronal 2D reformat clearly shows the gestational sac within the cervix.
And this was a proven cervical ectopic pregnancy.
This is a patient who had had a cesarean section and there is a sac like structure at the C-section scar.
And this is a coronal 3D reformat clearly showing you the location of this ectopic pregnancy at the cesarean scar.
This is a patient who has a uterine anomaly.
She has, this is a transabdominal image and it's showing a gestational sac in the left uterine horn.
And here we can clearly see on the 3D image.
This is a left IUP within a sub septate uterus.
This is a patient who has an arcuate uterus and then became pregnant and now has a normal IUP.
And this is a patient who has a C-section scar.
And on the coronal 2D you can actually see this is a cornua uterus.
I know that this is not a current pregnancy, however, you can see the scarring from the C-section and I couldn't resist putting in a case of a unicorn ate uterus.

Conclusion

So in conclusion, the ability to perform 2D and 3D reformats of the uterus and a nexa in the coronal, or actually any plane that you feel is important, is a valuable and important imaging tool.
It decreases the need for additional studies and additional diagnoses can be made.
And findings that are made on routine 2D imaging can be clarified and confirmed.
Consider performing 3D ultrasound on all female pelvis and early pregnancy ultrasound at your practice.
At my practice, this policy allows the text to maintain their skills.
There's no question about when do we do 3D ultrasound.
They just know to do it on everybody.
And the information is there if you need it.
It adds minimal time to the workflow and texts are properly trained and the volume data in the portals will allow offline reconstruction.
I'd like to acknowledge the sonographers at all my different centers because without their dedication and their support, we could not produce these images.
And I'd also like to thank the radiology IT team at my hospital.
Thank you very much.