0:01

Okay, so now we'll talk about endometriosis.

0:04

Again, this is a very common

0:06

disease that we may see.

0:09

when we're imaging our pelvic patients.

0:11

So I'm going to spend quite a bit of

0:13

time just talking about the disease

0:15

process and the imaging appearances.

0:17

So firstly, what is endometriosis?

0:20

Well, endometriosis is when there is endometrial

0:25

tissue that's located outside the uterus.

0:28

So it's abnormal placement

0:30

of endometrial tissue.

0:31

And this is quite a common disease.

0:33

It can affect up to 10 percent

0:36

of reproductive-aged women.

0:37

And the typical locations

0:40

of endometriosis are here.

0:42

Some of them are on the slide,

0:43

but usually the ovaries tend to be

0:46

involved, but there can be deposits of

0:48

endometriosis all throughout the pelvis.

0:50

So the uterine ligaments, the cul-de-sac,

0:52

the peritoneum, fallopian tubes, retrosigmoid

0:55

colon, and this makes it quite challenging.

0:59

sometimes to diagnose because the deposits can

1:02

be quite small and plaque-like in appearance.

1:05

So as radiologists, it's important to be aware

1:08

of these locations that are kind of atypical,

1:11

but also very important for us to be aware of.

1:14

So, I like to think about the rule

1:16

of tens with endometriosis as well.

1:19

So we know that up to 10 percent of

1:21

women can be affected, but routine pelvic

1:24

ultrasound accurately diagnoses endometriosis

1:28

in only about 10 percent of cases.

1:31

So if you think about that,

1:32

that's actually quite significant.

1:34

So, if a patient comes to your clinic or

1:36

your hospital with possible endometriosis

1:39

and you do a pelvic ultrasound, in 90 percent

1:42

of cases, we're missing the endometriosis.

1:45

So that's where MRI can really play

1:47

a significant role, even higher than

1:50

laparoscopy, as we'll learn shortly.

1:53

Endometriosis, as we now know, is often

1:56

under-recognized and under-treated, and

1:59

some patients have a very protracted

2:02

course and delayed diagnosis.

2:04

The average time to diagnosis is seven years.

2:07

So you can imagine if you're suffering with

2:09

those symptoms for seven years, that's a long

2:11

time to be going through without a diagnosis.

2:14

We still don't really know what the

2:16

pathogenesis of endometriosis is.

2:18

There are several theories out there

2:21

from retrograde menstruation to peritoneal

2:25

metaplasia to transformation of stem cells.

2:28

And we haven't really landed on the

2:30

exact cause, but unfortunately these poor

2:33

patients often undergo repeated imaging

2:35

studies, sometimes with no solid diagnosis.

2:39

And laparoscopy is often used for

2:43

diagnosis and for treatment as well.

2:45

And it's considered the gold

2:46

standard, but it also, unfortunately,

2:49

frequently underestimates the disease.

2:52

And there is a high false negative

2:53

rate for laparoscopy as well.

2:55

And that's partially due to the fact that

2:58

the laparoscopist can be blinded by the presence

3:02

of adhesions and scarring, which prevents

3:05

them from looking behind the uterus and into

3:07

the posterior compartment of the pelvis.

3:10

So deep deposits can be invisible to

3:12

the laparoscopist, and that's kind of

3:14

referred to as the iceberg phenomenon.

3:17

So you might see one tiny little

3:19

deposit, but you're not able to see

3:21

deep to that in the OR, but luckily MRI

3:24

does have a role to play there because

3:26

we can visualize those structures.

3:29

So what should we be

3:30

looking for as radiologists?

3:32

Well, we know that the ultrasound

3:34

diagnosis of an endometrioma alone is

3:37

really not enough because many patients

3:39

may not have any ovarian involvement.

3:42

So we can maximize our yield on

3:44

ultrasound by up to 80 percent by

3:47

looking for other manifestations.

3:48

So that includes deep infiltrating disease

3:51

of the bowel, deposits that might be present

3:54

in the retro-cervical space, adjacent to

3:57

the vagina, the bladder, and the ureter.

4:00

And another feature that we can look

4:01

for is frozen cul-de-sac, which is

4:03

important for surgical planning.

4:05

And I'll talk about that in just a moment.

4:07

There's lots of peritoneal

4:08

signs that we can also look for.

4:10

And if we're not aware of these,

4:12

obviously, we're going to miss them.

4:14

So you don't know what you don't know, right?

4:16

So.

4:17

As long as we're aware of these

4:18

peritoneal signs, we can start to look

4:21

for them both on ultrasound and MRI.

4:23

And some of those include filmy

4:25

adhesions and kissing ovaries.

4:28

So this is from abdominal imaging and just

4:30

looks at the different types of endometriotic

4:32

lesions on routine transvaginal ultrasound

4:36

and expert-guided transvaginal ultrasound.

4:38

So what is expert-guided ultrasound?

4:40

Well, it's an ultrasound that's

4:42

done in a dynamic way by an

4:44

expert in gynecologic imaging.

4:46

So many of us might be reporting pelvic

4:49

ultrasounds once they've already been completed

4:51

and the patient is no longer available.

4:54

But these expert-guided ultrasounds actually

4:57

are done by the radiologist on site in the

5:00

room using some of the dynamic maneuvers like

5:03

compression and different positions, et cetera.

5:05

So you can see how the detection of

5:09

abnormalities really increases when

5:11

the expert-guided approach is used.

5:14

So all radiologists really should be

5:15

aware of these manifestations, even if

5:17

you're not able to offer the service

5:19

of an expert doing the ultrasound.