Ultrasound of Premenopausal Ovaries - HD

Introduction to Premenopausal Ovaries

When Beverly told me the topic, I said,
I could have changed the title of this talk to,
what else can I tell you about premenopausal
ovaries you don't already know?
And I thought, it's always fun to review
what you know, and hopefully it can all come to a consensus
that you agree on the same things.

To begin
the ovary, what a wonderful organ.
I didn't realize that it is the most active organ in the
body or one of the most active organs in the body.
And those of us who image the ovary appreciate the fact
that it has progressed so many changes over the years.
And if things go well, you see the diagram on your right,
exactly the way the follicles behave when they're predicted
to rupture at 14 days.
Most of them hopefully do,
and some of them may take a few days, plus or minus,
but life goes on every month.
This whole cycle is repeated.
The ovary is a complex embryology and histology.
And to look at the number of cells that make up the ovary,
you can understand how the potential of each of those cells
to form a tumor makes the ovary a big organ
to monitor for possible tumors, malignancies,
or benign tumors.

Anatomy and Relationships of the Ovary

Now, it also is a favorite site
for metastasis from other organs, especially the breast,
colon, and stomach, and about five to 30% of cases.
And those of us who have looked at this diagram about
the great synchronicity between the pituitary, the,
the ovaries, the endometrium, and the hormones that go up
and down are scheduled, realize
that things don't always go exactly
the way you want them to go.
And we are there to look
for the reasons why these things do not happen.
And this is part of the excitement of imaging the ovary.

Now ultrasound, of course, is recognized as the modality
to monitor all the changes in the ovary,
especially transvaginal sonography.
It has allowed us to not only directly
evaluate the many ovarian functions,
more than any other modern technique.
It also allows us
to morphologically evaluate the ovary as an organ.
It has allowed us to offer more
assisted conception therapy services,
and for the first time,
we can better understand the physiology
and pathophysiology of ovarian blood flow
because of transvaginal color doppler.

So I hope in the next 20 minutes
or so I could go over this outline of presentation
that I thought would be a good review for,
for all of us in this room.
And I will skip through the ovarian masses pretty quickly
because I know you've seen all of them already.

So when I lecture to my residents,
I always show them this beautiful diagram from Dr.
Netter Siba GGI collection.
But I always preface it with, do not expect
to find the ovaries in exactly the location it is drawing
tells you, 'cause that's not reality.
Sure, you can find the left ovary maybe a little more
in a higher position than the right,
but always remember to look
for the right ovary in the cul-de-sac
because they have the propensity
to hide in there when you could not find them in the adnexal
area that you've been scanning.
But I thought this diagram, subtle shoe on
what the relationship
of the organs ideally should be in the pelvis if things
are ideal as this.

But you sometimes forget that the ovaries,
the ovaries are usually posterior
to an anti verted fl uterus.
And the ovarian ligament attaches the ovary to the uterus.
The fallopian tubes are supposed to be right next door.
You don't see the fallopian tubes
and until it fills up with some fluid or blood.
But look at the relationship of the ovary to the ureter
and the vessels that go along with it.
This is a good diagram to remind us
that pelvic pain is not always the problem
of the ovary or the uterus.
There are other things in the pelvis adjacent to the ovary,
the uterus that can produce that symptom.

Blood Supply to the Ovary

Now, nature made sure
that the ovary will always be supplied,
so it gave it two blood supplies.
One is from the ovarian arteries
that directly come off the aorta,
crosses the pelvic brim at the level
of the common iliac artery,
and then enters the dispensary ligament
to get into the ovary.
The second one is the ovarian branch of the uterine artery.
That anastomosis with the ovarian artery from the aorta
to provide the artery, the ovary with the blood supply needs
to carry on its function.

Ovarian Volumes and Measurements

Now, I'm not gonna go through these ovarian volumes,
but as you can see in a premenopausal woman,
the ovary can go up
to about 22 ccs maximum and still be normal.
But on the average, I think it's about 11
to 12 ccs using the formula of the ellipse
to compute ovarian volumes.

Now, technically, the ovary is really part of the adnexa,
but we don't just lump it with the adnexa.
We always say the ovary and the adnexa
because we want to underline
how important its function is compared
to all the other things that belong to the adnexa.

When we look for the ovaries, especially in patients
who are a little challenging to image,
we always use the external iliac vein
or the internal iliac artery as our landmarks to say
that this is where the ovaries should be
because they form the borders
of the ovary when we try to find them.

So yeah, we are one of the few people who image
ovaries this way,
but we also read from many centers that do it the other way,
but at least I know my residents can look at publications
from the UK or other European nations
that display their images this way.

So premenopausal ovary, you go for the volume
of the ellipse formula to get the volume.
And so you always measure the longitudinal
and the AP diameter on a sagittal view
and only use the transverse view
or the coronal view for the transverse measurement.
And here's one of our iliac vessels for guidance.

Follicular Development and Phases

Now, I used to think when I was in medical school
that follicles don't begin until after menses occurred.
But we all now know that recruitment of follicles begin
before the start of menses.
We start seeing follicles about day five to seven,
and the dominant follicle begins to show itself
around day eight to 12.
And the non-dominant follicles usually stay no larger than
about 14 millimeters in size.

Now, sometimes you could have bleeding into the follicle it
ovulation column, the corpus hemorrhagic,
but the corpus luteum can grow up to two
to three centimeters over the next four to five days
after ovulation.

Now, my reproductive endocrinologist colleague told me
that we only see corpus luteum cysts when the corpus
luteum hemorrhages.
He says, otherwise, you can just see the corpus luteum
as a vacant spot in the ovary
without necessarily forming a cyst.

So here's an adolescent ovary, I promise not
to talk about the uterus or the postmenopausal ovaries.
And the only reason why we know they are ovaries is
because there are follicles that we see no matter
how tiny they are,
and that they're adjacent to the pelvic sidewall that is
denoted by the artifact that you see from the bone.

Now in the early follicular phase, you can see the follicles start showing up,
but they're pretty much uniform in size.
In the late follicular
or periovulatory phase as reflected
by the endometrium, you start seeing the dominant follicle.
And on the other side,
the follicles do not declare one dominant or the other.
But because the other side is already determined
to be the dominant ovary for the month,
and the reproductive endocrinologists monitor these follicles
very frequently
because they don't want to harvest eggs
beyond the follicle size of two centimeters.
They said ideally they'd like to be at 1.5
between 1.5 and two.
So those of you who may work with
reproductive endocrinologists noted they're your urine.
They're beck and call
whenever they need to find the ideal time
to harvest the follicle.

As you can see on the non-active ovary of the month,
there is no dominant follicle.

Now, as you proceed to the luteal
or secretory phase, you can see
follicles that did not make it into being dominant.
But on the other side,
even if you don't see a corpus luteum cyst, you know
that the ovulation has already occurred as declared
by this vacant spot in the midst
of the normal looking follicles.

Doppler Evaluation of the Ovaries

Now, we don't do routine doppler evaluation of the ovaries,
but I do have a couple of colleagues
who will call a patient back if the sonographer did not get
the picture of the color doppler of the ovaries,
they just feel more comfortable if there's a picture
that shows color within the ovaries
saying that there's flow.
But what it teaches us is not only can you tell
where which one is the ovary of the month,
because it always has a high velocity lower resistance flow
compared to the quiescent ovary
that has a high resistance flow.
And resistive indices of ovarian flow are the lowest
just before ovulation, hours before the ovulation.
And in corpus luteum is maintained, then you,
the RI remains low until the cycle starts all over again.
You can also tell by using power doppler, which
of the follicles are probably ones
that are gonna ovulate because they received the most flow.

Consensus Guidelines for Asymptomatic Ovarian Cysts

Now in 2009, we all know that that's when the landmark
consensus conference on the management of asymptomatic ovarian cysts happened.
This was the program of the day that the experts from different specialties came together.
I think it's over in the Tel Hotel now over there in the across the street.
And on the second day they came to a consensus
that was published a year later in radiology.
And we know that we keep this article
in our reading room areas for reference for newbies
or to show clinicians that this is where we come up
with the idea of no recommendation for follow up
or suggest further evaluation depending on the
criteria outlined in this article.
And this is a must read article for my residents.

It also is interesting to find out that the Royal College
of Obstetricians
and Gynecologists in cooperation with the British Society
of Gynecological Endoscopy came up
with their own guidelines about a year
after we came up with ours.
And according to the background and introduction
provided in that document, they claim that about up to 10%
of women will have some form of surgery
during their lifetime because of an ovarian mass.
The premenopausal woman almost has
ovarian masses in cyst that are predominantly benign.
But the chances of
a symptomatic ovarian cyst being malignant
in a premenopausal woman is pegged at one in 1000,
increasing to about three
to one in 1000 at the age of 50 years.
And it also agrees that differentiation between benign
and malignant ovarian masses could be problematic except
for some germ cell tumors that have markers like HCG and Alpha-Fetoprotein that will more
or less cue you on the nature of that ovarian mass.
But there are a lot of masses, about 10% of them
that end up being non ovarian in origin.
And you can see the list of masses that they put in the first table of this guideline.

So they also recommended
that ultrasound is the primary imaging
for assessing ovarian masses.
And at the present time, do not recommend CT or MRI
because they do not improve sensitivity
or specificity that we get by transvaginal sonography.
And to me, what is most interesting is a year
after we came out with our guidelines for the management
of asymptomatic ovarian cyst, the British organization
embraced our recommendations.
So the SRU has done a great thing,
and it's just not for us consumption.
It is now also held by our colleagues across the channel.

Benign Ovarian Cysts

Simple Cysts

So we all know what a simple cyst look like.
We know it's an ovarian cyst
because the follicles are squashed by this beautiful,
anechoic simple cyst.
And obviously trying
to image the same cyst in a transabdominal approach is not
gonna give you the resolution
and the beautiful definition of the wall.
So that simple cyst, and
whenever we see a benign looking simple cyst,
we always assume that they're either follicular corpus luteum.
It may be some paraovarian cyst,
but these should all be reported as benign.

Corpus Luteum Cysts

In reproductive age women, corpus luteum cysts are common,
especially when you see this rich blood supply that goes around it.
Sometimes they could even be more than this
and be called a ring of fire
because corpus cysts have been reported to have more
of this ring of fire phenomenon more than
an ectopic pregnancy.
So we use the same criteria that we use for any cyst, but
because it's associated with a pregnancy,
we always assume it's a corpus luteum cyst.
And if it's complicated, you may recommend a follow up
as needed, but most of the time,
if you think it's a corpus luteum, you do not have
to recommend a follow up.

Hemorrhagic Cysts

Now, the time of the oral boards for radiology,
I still remember whenever we would go to Louisville
to give oral boards, there is always a case
of hemorrhagic cyst in the pile every half day.
There's always a hemorrhagic cyst,
but they're all given in different stages of development.
And all we wanted to hear is the examinee mentioning
hemorrhagic ovarian cyst, at least in their differential,
being cognizant of the fact
that they could change depending on the timing
of the imaging versus the state
of the clot retraction.

So we are familiar
with the so-called fish netting appearance,
the retracting clot, no internal flow.
And because they are not simple, we could recommend
a remote follow up for a cyst
that is more than five centimeters
because of the remote chance of malignancy.
But when you have this very typical findings, especially
when you follow them up later, they either decrease in size
or convert from a low resistance doppler pattern
to a high resistance doppler pattern, then you rest assured
that you were dealing with the physiologic cyst
that just happened to be hemorrhagic.

Endometriomas

Other benign cyst that we have encountered endometriomas,
they always look like that.
No matter what you do, they always don't change.
They look like that every time.
Sometimes they might even show you this layered
appearance because old blood
and new blood can come together.
The chocolate cyst nomenclature refers to the fact
that you always find thick blood clots
and new blood combined when you open the cyst.
There could be layering debris.
They usually have thick walls
and again, no doppler flow in the walls.

Now, sometimes they may come to you in the middle
of the night, be requested
to do an ultrasound on a very tender abdominal lump
that turns out to be an endometrial implant.
And these are very tender.
And sometimes if you have not seen one
before, you might worry that this could be some kind
of sarcoma or something,
but it is known to appear as a lump that is very tender
in the superficial abdomen.

Dermoids

We know what dermoids look like,
but again, to underline the fact that transvaginal is the way
to go, this is the same cyst.
You just don't see any
of this detail in a transabdominal scan.
So even if you see the problem transabdominally
and you can measure it and you know where it is,
it's always best to do a transvaginal to see the typical
dermoid plug and the sebum
that you see there, the hair floating in the sebum,
the shadowing dense material like cartilage,
bone, whatever, teeth.
And to me, dermoid is always a good differential
for any mass that you see in the pelvis.
And that's what I tell my residents all the time
when I give a lecture on Dermoids.

Oh, we show this. This is my first dermoid.
I was so proud of having made this pickup early in my career.
And just because we saw an incidental series
of molars in the left side of the pelvis
and we decided to suggest an ultrasound
and found this dermoid that has the typical strands
of hair floating in it.
But this is definitely dated,
because this was one of our very first ultrasound machines.

Solid Ovarian Tumors and Malignancies

Solid Ovarian Tumors

What about solid ovarian tumors?
It is said that predominantly solid ovarian neoplasms are a
minority in the premenopausal woman
and they are predominantly benign.
And you can see the list of what they are.
28% are epithelial in origin.
22% are germ cell tumor in origin.
This is where the germin and the teratoma come in.
And you have 21% sex cord stromal tumor origin
and metastatic tumors.
The Krukenberg tumors account for about 20%
of all the predominantly solid ovarian tumors.

Ovarian Malignancies

Now we know what cancer looks like
and it is interesting that it is the most common cause
of cancer death from gynecologic tumors in the
United States, but it's barely mentioned in the incidence
table that I'll show you in a minute.
They include primary lesions arising from
normal structures in the ovary.
And again, epithelial ovarian cancer is the majority
of ovarian malignancies.
And the germ cell
and sex cord and the metastatic tumors are in the minority.

Now if you look at the American Cancer Society graph,
you can see that the ovary is not even on this list as far
as estimated new cases go.
But look at where it is in the estimated deaths.
It's second to breast among the gynecologic cancers
as the estimated cause of death.
So that is why we still have a problem
in putting out a reliable ovarian cancer screening program.
And I know that we're still working in the era of genomics,
so hopefully one of these days we will have a more efficient
way of monitoring ovaries rather than answering phone calls
asking for screening ultrasounds
because somebody had a grandmother
that died of ovarian cancer.

We know what the malignant cystic ovarian tumors look like.
Not only are they full of debris,
they have very irregular thick nodules,
confirmed on CT.
They could have flow. And this is probably one of the best
evidence that you have that you're dealing with a
aggressively growing tumor.
When you see blood flow in this thick septa,
sometimes when you have other diseases
that invade the ovary, you could have a hypoechoic mass
with very irregular borders mixed in
with the follicles in the normal ovarian tissue.
This one happens to be lymphoma affecting the ovary
and the high velocity low resistance blood flow that we see
both in malignant tumors
and in rip roaring acute PID is always indicative
of a rapidly metabolizing mass.

Polycystic Ovarian Syndrome (PCOS)

So what about polycystic ovarian disease?
My residents always ask me whether this is a diagnosis we
should make, knowing that there's a series of laboratory
and clinical scenarios that
would make the diagnosis rather than us suggesting it.
But we see this configuration all the time to
where if there is no clinical indication for PCOS
and the medical record doesn't say anything about PCOS,
we always say something like the appearance
of the ovaries are consistent with
PCOS given the right clinical setting.
So hopefully it calls the attention of the clinicians
to look into that possibility even if there are no classic
symptoms that go with it.

One thing that I read lately,
which I thought was eye-opening,
because I always thought
that polycystic ovarian syndrome was an ovarian issue,
nowadays it is thought to be a result
of endocrine disorders characterized by a series
of hormone imbalances.
So it's not really the ovaries fault,
it's just called polycystic ovarian disease
because of that manifestation.

So hyperandrogenism
and insulin resistance combine to produce the results of
what we see in PCOS clinically, the hyperandrogenism,
it's from the excess testosterone
that's produced in this disease, they can prevent ovulation.
Thus, the amenorrhea
and insulin resistance component causes excessive insulin
and glucose in the blood
and in turn continue to pump out excess estrogen
destabilizing the whole hormonal system.
On top of that, the excess insulin causes the ovaries
to produce excess testosterone in just confounding the whole
problem, and it increases the conversion of testosterone
to estrogen, which affects weight gain
and the formation of ovarian cyst.

So from a systemic point of view, PCOS is likely due
to a continuing hormonal imbalance rather than the
fault of the ovary.

So they always look like this.
And when you see a big thick stroma
with more than 10 follicles that are uniform in size,
that rim the whole ovary,
and you start suggesting that it may be PCOS
because it always looks like that
many different patients always show you this beautiful
pattern of a thick ovarian stroma
and a lot of tiny follicles rimming the rim.

Ovarian Torsion

What about torsion?
There's a lot of literature
and torsion that educates us about when we should call it.
So torsion usually does not give you a normal
looking ovary picture.
That's why to me, if the ovary looks perfectly normal,
chances are you're not dealing
with an acute torsion at the time
that the ER sends you the patient.
But it constitutes 35%
of GYN emergencies happens more in premenopausal women.
And if there is a mass that serves as the focal point,
that's where the torsion tend to happen.
That's why they say torsion of a normal adnexa is rare.

We are familiar with the signs of patients that present
with ovarian torsion.
And from these article you can see this beautiful enlarged ovary
with free fluid.
Usually these ovaries are so big
and they're located in an unusual location for an ovary
and you should be looking for coiled or twisted vessels.

Now, personally I've never seen this,
but this article in 2004 claimed that all 21 patients
showed the whirlpool sign.
And if you happen to cut them on a sagittal view,
you can see the twisted pedicle here
and the vessels that go around the whirlpool sign.
And this is correlated by a laparoscopic appearance
of the torsed ovary in comparison
to the normal ovary on the other side.

Doppler in Ovarian Torsion

Now, doppler and torsion, I'm sure you must have called been called several times by sonographers
and residents to say, well, there's flow in the ovaries
so there couldn't be torsion.
We are told that the presence
of the central venous flow is predictive
of ovarian viability.
But just
because you see arterial flow does not mean
that torsion is absent.
You got a bad looking ovary
and all you see is arterial flow.
You have to keep looking for the central venous flow
that would help you say that the ovary is probably viable.
However, in partial torsion or repeated torsion
and torsion, this criteria could be a problematic thing.

So this is my official ovarian torsion slide
because there was a simple cyst right next
to the torsed ovary.
We did see some venous flow in the periphery,
but this is the one place that we found it,
it was never found within the big ovary.
It was an occasional arterial flow,
but most of the torsed ovary looked more like no flow at all.
And it was proven to be torsion at surgery.

So torsion assess ovarian location, if there's a cyst
or mass be suspicious, look for the pedicle sign,
and if the ovary looks perfectly normal,
it's probably not torsed.

Ovarian Hyperstimulation Syndrome (OHSS)

How about ovarian hyperstimulation syndrome?
I have seen a few of this and to me they're fascinating
because if they come in with a history of yeah,
I've had some fertility procedures done,
then you can say, yeah, that's OHSS.
And the ovary undergoes extensive luteinization
releasing large amounts of estrogen progesterone,
and that's what produces the shift
of the intravascular compartment to the pleural
and abdominal cavities.

But sometimes you see these in normal pregnancies,
I've seen several of these
and these are not palpable clinically even at the
size that they are.
So what do you do? You wait,
because even if they're 17, 20 centimeters bilaterally,
patient is asymptomatic,
of course your advise just in case it becomes torsed
or hemorrhagic and you have to come to the ER for that.
But if you just wait, they will
regress two months postpartum.
They could look almost normal.

And so this goes to the category of touch me not cysts.

Ovarian Ectopic Pregnancy

And finally, as rare
as an ovarian ectopic is, they do occur.
I've never seen one.
So I had to borrow one from the internet.
We thought at first this was sort ovarian ectopic.
But you can see that the ovary is clearly not part
of this whole gestational sac.
To have an ovarian ectopic, you should have one
that is surrounded by ovarian tissue.
And so from the internet to get these pictures
that have follicles that tell you that, yeah, that's,
that's definitely within the ovary, that's the only way
that you could make the diagnosis of an ovarian ectopic.
But most of the time these are probably corpus luteum
cysts or hemorrhagic cysts in the ovary.

Summary

So in summary, to get good
and adequate evaluation of the premenopausal ovary,
we all have to be conscious of
how dynamic this change is in the ovary,
and always know more
or less where we are in that cycle related
to the patient's last menstrual period,
which should be the number one question you should ask your
patient that comes in for a pelvic ultrasound.

And to me, having the SRU consensus guidelines in your
reading room pasted on the wall as referenced
before you follow up ovarian cyst benign
or recommend further evaluation is has been very helpful.
So if you don't have that in your reading room yet,
just print the article, stick it on a transparent cover
and hang it with Velcro strips on the wall
of your reading area because you're gonna need it.

So with that, I end this lecture and thank you very much.