2D/3D Transperineal Sonography of Pelvic Floors Disorders: An Overview - SD

Introduction

I am Art Fleischer, chief of ultrasound at Vanderbilt University Medical Center in Nashville, Tennessee.

This presentation will provide an overview of the application of transperineal ultrasound in evaluating pelvic floor disorders.

This presentation will discuss and illustrate the role of 2D and 3D trans peroneal sonography in evaluating women with pelvic floor disorders.

I want to thank my clinical colleague, Dr. Carl Zimmerman at Vanderbilt, and also acknowledge the input from Dr. Dietz, who is an expert in this area at the University of Sydney.

I have no disclosures to make except I'm a big Braves fan, and this is a picture of people playing golf.

Difference Between Imager and Clinician

There's a big difference between the imager and the clinician in evaluating pelvic floor disorders.

The clinician, of course, has a good idea of the clinical problem and the surgical approach to those problems.

The imager is just beginning to understand what anatomic factors are important.

Major Application of Ultrasound

This is a major application for ultrasound and I'm showing a picture here of the astronauts on the shuttle using ultrasound, understanding that they could do deep vein thrombosis evaluation on the shuttle.

And also parenthetically write a paper on the role of ultrasound in using ultrasound to determine rotator cuff in injuries.

And interestingly enough, that paper had a reprint request that was not on the earth for the first time.

The reprint request was the International Space Station.

Presentation Overview

Basically I'd like to talk about improving the understanding of these disorders with 2D and 3D ultrasound present the clinical context, the role of imaging discuss the role of trans peroneal ultrasound relative to M-R-I.

M-R-I is an excellent means for detecting pelvic floor disorders and showing them in a dynamic sense, but we feel that trans peroneal approaches are excellent as well.

I use many references and these are just an example of the references that I'm using.

I want to point out that there are cases that have been lent to me by Dr. Dietz that are at a website.

And these are important to appreciate because they show the dynamic aspect of the disorders.

Types of Pelvic Floor Disorders

In pelvic floor disorders, they basically break down into three main abnormalities, stress urinary incontinence, pelvic organ prolapse, and fecal incontinence.

For stress urinary incontinence what we would see on ultrasound is funneling of the internal urethral ATU on Val Salva, or at rest.

We will see abnormalities in the retro vesicle angle, which I will show you.

And the bladder neck descent for pelvic organ prolapse movement of pelvic organs such as the uterus, the vagina, the rectum being below a particular reference line.

I might add that MR has a very nice way of showing this objectively and globally.

And so trans perineal ultrasound is admittedly more subjective, but has the ability to look at this in a dynamic fashion.

I will not address fecal incontinence, but with ultrasound we can show thinning and disruption of the internal and external a**l sphincters.

Assessment of Prolapse Problems

Another very important application of transperineal ultrasound is assessment of prolapse problems, particularly after they've been surgically treated with a variety of tapes meshes and other agents.

The tapes are the tension free tape, TVT, the trans Obterator tape, which is now called Monarch, and the Perge and the Apogee, which are meshes.

And I won't be discussing the role of ultrasound for seeing the urethra post the injection of bulking agents, but this is another application.

Overview of Pelvic Floor Disorders

As an overview, pelvic floor disorders affect up to 50% of post-menopausal women, and of these 10 to 20% will be symptomatic of the affected women.

One in 10 will be projected to have some type of surgical procedure over the next 30 years.

It's a projected major increase in the demand for imaging and clinical management of women with pelvic floor disease.

Pelvic floor disorders are traceable to birth and surgical trauma in that these disorders result in weak, torn, or thin pelvic muscles, ligaments and fascia leading to loss of pelvic organ support, which contributes to abnormal pelvic organ mobility and prolapse leading to the symptoms of pain, pressure, incontinence, retention, fecal incontinence, retention, constipation.

And it's a multifactorial group of disorders and it affects different compartments.

Compartments are considered anterior, middle, and posterior, and I will refer to this in a little bit.

Associated Factors

Other factors associated with pelvic floor disorders are typically parity and patients that are post hysterectomy and other pelvic surgeries.

And there is a genetic risk factor for Hispanics, people of Marfan syndrome, but there seems to be a decreased risk for African Americans.

Modalities for Evaluation

The modalities that can be used for pelvic floor disorder evaluation include trans perineal scanning, which is when the ultrasound is put on the perineum.

We can do this in 2D 3D and now in four D, which is with a matrix array probes.

We can also use transvaginal probes, endo a**l probes as well.

Obviously magnetic resonance imaging MRI is excellent and can be a backup to ultrasound voiding cysto ethnography.

There radiographic technique for looking at the bladder and the urethra.

Fluoroscopic defecography can be used for looking at fecal incontinence and colonic transit studies.

Pelvic Diaphragm Anatomy

This is a diagram of the pelvic diaphragm.

The diaphragm basically is at the base of the bladder, the vagina and the rectum as shown in this modified diagram as shown in the sagittal plane with a patient in the upright position as imaged from below.

I show the levator anai muscles the pubovisceral complex, which is basically made up of puborectalis and the pubococcygeus muscles.

And also shown here are endopelvic fascia and the ligaments.

And this makes up the pelvic diaphragm.

Now I want to show you some pictures trying to show this in 3D so you get in your mind what the important structures are.

As you can see, there's the urethra, the vagina, and the rectum, and the surrounding musculature, which is basically levator ani muscles.

The puborectalis pubococcygeus.

As you can see in this image, as if you're looking down into the pelvis, this is the pelvic diaphragm from above.

Terms and Structures

The terms that are going to be used include the technique, whether we're using 2D or convex linear transvaginal probe, or the 3D hybrid probe, which is basically a mechanical sector.

I'll talk about structures in their sagittal axial and coronal planes.

And the pelvic structures that I'll be referring to are the urethra the vagina, the uterus, the rectum anus, and the levator ani muscles.

Evolution of Ultrasound Technology

Now in ultrasound we've evolved from the original real time, which is a mechanical sector rotating group of transducers to linear arrays, to curvilinear to mechanical curves with a mechanical movement of that transducer array.

Now to 2D electronic matrix array.

I think the best way of starting and evaluating the pelvic floor is using this type of curved linear array and use it in the 2D mode.

Now we can also use, depending on the surface that we're imaging, the transvaginal probes, and this is a picture from the Phillips company of their new 3D nine three transducer, which allows us to image in 3D.

And this on the other hand is the larger trans perineal probe used in obstetrics.

And this diagram shows very nicely the sweep that is obtained in the plane of the transducer.

And then we can reconstruct, once we get this information, we can reconstruct in the axial or the coronal plane.

The newer matrix array probe design is shown in this animation where there are send receive elements and the 3D volume can be interrogated in real time in any particular plane.

These are very exciting potential applications in this area.

So basically what I'm trying to say is that you select the transducer probe according to the area of interest in small confined places, you would use a tightly curved convex probe, a transvaginal probe.

If you're going to look for large areas of interest with large sectors, you can do the 2D curvilinear array.

And it's very analogous to doing surgery with different instruments.

Different instruments allow you to get to different areas and have different functions.

The same thing is true with ultrasound probes.

Now I refer back to this group of diagrams showing the pelvic floor, the pelvic diaphragm as imaged from below as imaged from above.

And the three main structures that we're interested in in the axial plane.

So in the axial plane, we see the urethra at the top of the image, the vagina in the middle, and the rectum at the bottom of the image with the levator ani muscles surrounding that.

Again, this is from above as if we're looking down into the pelvic brim from above.

Again, one has to be very familiar with these structures in order to make accurate diagnosis.

And this is from a little bit further back, and this helps us really understand what we're going to be required to see in the 2D plane.

Normal Anatomy Imaging

In normal anatomy, we see the urethra the bladder, the cervix, the uterus, the rectum, the anus, and the pelvic floor.

So in this labeled image, and I have a diagram next to it, we can see very nicely the symphysis pubis, the urethra, which is hypoechoic, the bladder, the vagina, and the rectum and anus.

Now the urethra is hypoechoic because the muscle bundles run in that plane.

It's not because there's fluid in the urethra.

You'll note that in this diagram, taken from the book ultrasound anatomy, the scan plane is shown as well.

Okay, if we turn that probe 90 degrees and we image on the perineum, we'll see this anatomy, we'll see the urethra in long axis, the bladder and the vaginal wall.

So if we use a smaller transducer, namely the transvaginal probe, this is the anatomy we'll see.

You remember, we're tipping the image up in 90 degrees.

We see the symphysis pubis, we see the urethra, we see the vagina, we see the rectum and anus.

And if we turn 90 degrees, we'll see this anatomy symphysis pubis, urethra, bladder, vagina and rectum.

So we need to be very familiar with this anatomy.

We can use a high resolution, which basically decreases our penetration, but we can see different structures of the urethra.

As shown here in this linear array placed on the perineum, we see the urethra, we see the orifice, and we see the really detailed structures of vagina.

If we turn it 90 degrees, this is what we see.

The urethra is hypoechoic in the center, the vesicovaginal fascia, and the vagina in the back.

And this is just another image obtained a little bit further up showing the urethral orifice and some of the anatomy.

Now here's an image where we are in the axial plane and we see the urethra, vagina and anus, and we can depict the levator ani muscles as well.

This is another picture, as you can see further toward the sacrum, where we depict the urethra the vagina, which is a hyperechoic structure.

And the levator ani muscles and the anus, we can see on this image the external and internal sphincters.

Dynamic Imaging

Okay, enough about static imaging.

What can we see when the patient is asked to strain or Valsalva?

We can see in normal patients, the descent of the bladder neck should be less than 30 millimeters.

We can see that the retrovesical angle should be between 90 and 120 degrees.

And we'll see this on dynamic images later in this presentation.

So this is what I'm measuring.

The retrovesical angle as shown here, and the bladder neck descent is also shown on this diagram.

And this is more of the same with the high resolution image.

And this is the retrovesical angle at rest.

And now when the patient is asked to strain down, the difference between the two, this is at rest, this is at Valsalva.

So the retrovesical angle can be calculated.

And in this case, of course, it's less than 120 degrees and the bladder descent is less than 30 millimeters.

So this would be normal.

So Dr. Dietz has published in several journals the finding of how to quantify the bladder neck descent.

And I've shown you very briefly how to quantitate this.

And you can refer to his articles that are excellent on this topic.

This is another image of quantifying the descent of the bladder in the first attempted Valsalva.

And that really straining down.

And I found that you really have to stress to the patient that they need to bear down and not worry about losing their urine on the table.

But to see the dynamics of abnormal pelvic floor, you have to emphasize to the patient to try to reproduce their symptoms by asking them to really bear down.

Color Doppler Applications

Okay, on color doppler, this is potential applications.

This nice diagram shows all the urethral arteries, and perhaps in the future, some of these could be doppler interrogated.

And this is some of the vascular anatomy associated with these structures.

And this is a spectrum from the vaginal artery looking at the typical waveform and the intramuscular artery of the urethra and the periurethral artery.

Anus Imaging

Okay, how about images of the anus?

And again, I'm not going to discuss fecal incontinence, but this is the anatomy.

If we use a small transducer such as the transvaginal probe angle down, we get an image such as this showing the internal and external sphincters.

And we can quantitate this very nicely.

We can look for tears that are very important to determine.

And again, this is the anatomy that one would see using this.

3D Imaging

Okay, now, if we use the 3D capability of the transducer, we can image vagina, urethra, rectum, anus, and pelvic floor muscles.

So here's a reconstructed image that has been processed, and we can see beautifully the vagina producing the W or the H.

On this image we see the a**l canal, and this is in the lower portion of vagina.

We can see the puborectalis muscle.

Here is about midway.

We can see in this normal patient that the vagina has kind of a H or W configuration, the urethra and the a**l canal.

And this is further back, we can see that urethra, vaginal wall and rectum in a normal and a little bit angled.

We can see the, again, normal structures, the urethra, vagina, and rectum.

Okay, now a little bit more of these muscles.

I think it's important to realize what we're looking at.

If we want to look at the external sphincters, we can do this, shown beautifully here.

And in these images that are basically axial images and post-process, and these again are the major structures that one wants to see, the vagina, the urethra, the rectum, and of course some of the muscles that we see.

Now this is a picture from Dr. Dietz's excellent book, a video showing the images in 3D.

And what we see here in the top left is the sagittal image and the top right, we see 90 degrees to that or orthogonal.

As this patient is bearing down this normal, we see the coronal image, then we see the actual image as it's obtained and rotated 90 degrees in the bottom right image.

And so basically the most important images are the sagittal image and the reformatted axial image, as we see here in this C loop.

And this, again, would be a very nice example of normal in resting and straining down.

So to emphasize this anatomy, people have basically separated anterior, middle, and posterior compartments.

The anterior compartment the bladder, the urethra, the middle is the vagina and uterus, and the posterior is the rectum and anus.

Now this is a very simplistic approach I might add.

Most pelvic floor disorders are multi compartment, and they present to the clinician such as shown in this netter diagram.

Prolapse Types and Quantification

A large cystocele basically is a bulge as you look in, and you're not sure really if that's a cystocele or a rectocele based on just visual inspection because here is a rectocele.

They look to me very similar.

Now at the bottom we see a variation of rectocele, which is an enterocele, which is small bowel that's herniating down between the uterus and her rectum.

And these are netter diagrams of degrees of uterine prolapse.

You can see various degrees of uterine prolapse.

Now how do we quantitate this on transperineal imaging?

The diagram shows a very nice clear line between symphysis pubis and the perineal body, which is not shown here, and structures that herniate inferior past this line, cystocele or rectocele, are shown very nicely in this diagram.

Well, you can see on MR, this pubococcygeal line is a very easy line to draw and to conceptualize in the sagittal plane.

And they have gone further in defining H lines and M lines.

That is the MR group in looking at hiatal.

And M is mid and determining what is normal.

Now an MR this is a clear example of a cystocele taken from the excellent book by Dr. Laude Decker from wake Forest.

And you can see clearly that a Q-tip test where you put a Q-tip in the urethra would be clearly positive.

And clearly this is a cystocele.

This on the other hand is a rectocele, and the beauty of MR is that one can see lots of anatomy and get global depictions of that anatomy.

However, we know that there are limitations with MR.

Transperineal Technique

I'd like to maybe talk a little bit more about the trans perineal technique.

It can be performed in the supine or in fact in the erect position, which is more physiologic I might add.

It can be performed with 2D 3D.

And there's something called tomographic ultrasound imaging, which I can clarify further in another slide coming up.

So we put the glove over the transvaginal or the trans perineal approach probe.

You use four to five megahertz.

We want at least a five centimeter footprint for looking at the entire perineum.

Post-processing can be done with speckle reduction and color processing.

We image at rest and Valsalva, we cine loop and we can measure, as I mentioned, the following things, bladder neck descent, retrovesical angle, hiatal area.

Advantages of course, there's no ionizing radiation with trans perineal scanning.

It's dynamic, cheaper, easier on the patient and the examiner, and we can see things that MR can't see.

The tension-free tape, the slings and the meshes are seen on trans perineal.

The limitations, well, multi compartment disease are difficult to really conceptualize when you see all of the structures.

Operator dependence of ultrasound is clearly known, limited field of view.

There's not really standards yet for prolapse, but there probably will be.

And equipment variations, I would recommend that people start using a curvilinear in the sagittal plane because that really makes sense when you first start out.

And looking at the dynamic aspects.

Remember as shown in this diagram from Dr. Dietz that we can press on the perineal area.

It doesn't produce any discomfort in the patient or in fact in a plastic model like this.

Imaging Examples

Okay, so here's some pictures where imaging at rest in Valsalva.

We can see initially the urethra very nicely at Valsalva.

There clearly is a small cystocele.

The urethral angle exceeds that 120 degrees that we talk about.

And I recommend referring to his excellent works that are in multiple journals.

In fact, his excellent book that is I think a classic already for looking at urethral and pelvic floor disorders.

And these images are from his book with his kind permission.

This is a large cystocele.

As you can see here on the Valsalva.

There's a large cystic structure, which in fact is the bladder coming up right next to the transducer.

And here clinically, this patient was thought to have a rectocele.

And these are three different patients.

The one on the far left is a rectocele with gas in the rectum going inferior to the plane, shown as marked.

On the right is an enterocele case, which I'll show you in dynamic fashion.

And the middle is hypermobility of the pelvis.

Okay remember with 3D we can image and the sagittal plane reconstruct in the axial plane.

These are the images that we see.

Here we see a mid sagittal, a coronal, and an axial plane.

The axial plane is tilted 90 degrees to form the excellent image with as you can see here, and appropriately marked.

And this is again from Dr. Dietz's excellent work showing what all these images look like in a normal patient in real time.

And the top image is the sagittal image, the top left, I should say.

And the bottom right is the axial image that is the most important.

And you can see that the vagina maintains its H or W configuration.

Okay, a few examples of abnormal in 3D is diverticulum, as you can see here in this excellent example, a little cystic structure related to the proximal urethra on the sagittal.

And this is the possible rectocele that I mentioned.

And the drawing of the line, which I also have referred to.

This is an example from Dietz of a rectocele.

You can see the asterisk refers shows a echogenic structure that goes beyond the line that we drew, and that's an example of rectocele.

Well, meshes are used a lot in around the world for prolapse surgery.

They seem to have problems in contraction or retraction or dislodgement.

And this can be shown with transperineal imaging.

Here's a nice example of normal so-called tapes, or this is at the top is the tension free tape right below the urethra and the monarch tape.

And this is shown in the sagittal, but the axial plane shows beautifully the tension free tape at the top and the transobturator tape at the bottom.

This is a patient that had problems and the tape had to be broken.

And you can see the broken interface of the surgical treatment of this tape.

This patient has both meshes and an eg and an apogee implantation that actually is in good position.

And it's appropriately marked here.

Okay, herniation or evulsion of the levator ani muscle is shown in this nice picture from Dietz's work where the short arrow is the puborectalis that is retracted.

And so this is the clinical image that he shows where there's a break in the vaginal wall with herniation, and you can see it beautifully on ultrasound.

And the corresponding image on MR is, I think, of lesser quality, in fact.

Tomographic Ultrasound Imaging

Okay, tomographic ultrasound imaging is shown here, and we can take images at certain millimeter cuts, and this is the same patient showing where the asterisk is, the avulsion of that levator muscle.

We can measure the hiatus.

And these are images showing normal versus ballooning after avulsion injury of the levator muscle.

And here's some static imaging of cystoceles and rectoceles after Pergee which is a mesh.

This is a rectocele and a cystocele again after mesh placement.

Now the best way to show this, I think, is in cine format, and I would recommend that you refer to Dr. Dietz's work.

I am fortunate in having this on the website for my big book.

And you can go to www.sonobooksevene.com and see these images.

So this first patient in the sagittal plane, you can see beautifully that the cystocele forms, it's in fact superior to this mesh here.

And this would be again a cystocele after a mesh is put in.

And this would be a patient that would need to actually go in and have this revised 'cause the bladder is herniating superior to the mesh.

This is a normal patient.

And we can see this echogenic structure right here, which is actually the tension free tape, the TVT, which amazingly enough moves that much and causes the urethra not to bulge or funnel.

And this would be normal, this is a patient that has an enterocele.

And you can see here in the back that on straining there's bowel that is herniating between vagina and rectum.

And these are beautiful dynamic images with Dr. Dietz's permission that I'm showing as very straightforward examples of pelvic floor disorders using simple 2D technology.

Okay, now I'm going to show this in the 3D format.

So this is sagittal, coronal, axial and axial.

And in this patient we can see that the rectum is herniating into the anus.

And so this is a cystocele as well as a rectal intussusception.

And we can appreciate this on the dynamic aspects of 3D.

Again, here's the rectum coming to the anus.

There's herniation, there's intussusception here.

The and the bladder is passing beyond our line that we draw mentally.

And so this is a combination of a cystocele and rectal intussusception.

Again, I highly recommend to go to Dr. Dietz's book and see some of these images.

The final image is a patient that has a cystocele and rectocele.

And the levator ani muscles have been avulsed.

So there's marked ballooning here of these structures in the hiatus region.

And again, I think that it's important for you to go and see this in a dynamic fashion.

So to get kind of an idea of what you should be seeing in normal and abnormal cases.

Summary

So in summary, transperineal imaging pelvic floor is a common problem and it's a somewhat complex problem.

But with ultrasound, we can see the tapes, the slings, the meshes in both 3D and 4D format.

It enables better understanding of the dynamics and potential treatment for patients with pelvic floor disorders.

And I think the role of matrix array in the near future will be significant in allowing us to see this in real time.

I want to thank these people listed here, Wesley for helping me with the cine loops and getting them Dr. Freeman, who is a very excellent gynecologist in Augusta, Georgia.

And I have appreciated his clinical opinions over many years.

Dr. John Bobbit, who's helped with the videos here, the two medical students, my very capable administrative assistant.

And last but clearly not least, the sonographers, both at Vanderbilt and at our centers for Women's Imaging.

Thank you very much.