0:01

And then we've got the third pattern,

0:02

which is the deep or solid infiltrating type.

0:05

And again, remember that in this subset,

0:08

we've got endometrial deposits,

0:10

which are more than five millimeters below

0:12

the peritoneal surface, so typically

0:15

not seen at the time of laparoscopy.

0:17

So we talked a little bit about frozen cul-de-sac

0:19

earlier, so now we can define what that is.

0:23

So frozen cul-de-sac happens when there's

0:26

lack of mobility of the uterus,

0:28

which normally slides around it against

0:31

adjacent structures.

0:32

But because of adhesions along the posterior

0:36

cul-de-sac, that mobility may no longer be visible.

0:39

And this is again a dynamic finding,

0:42

which typically is seen on transvaginal scanning.

0:44

So if you've got experts in ventriculographic

0:47

imaging at your institution, they're well

0:50

aware of the different positions and the

0:51

different compression that's required to

0:54

assess for the presence of frozen cul-de-sac.

0:57

So this is typically an ultrasound

0:58

finding and not an MRI finding.

1:00

Torus uterinus involvement is definitely

1:04

something that we can see on MRI,

1:06

and I'll talk about that in more detail,

1:07

what that is and what we look for.

1:10

And then we can have organ and posterior

1:12

compartment involvement as well.

1:14

So we might have bladder involvement,

1:17

typically the posterior wall, and in

1:19

severe cases, patients might present

1:21

with dysuria or even hematuria,

1:23

depending on the depth of involvement.

1:25

Okay.

1:25

Thanks.

1:26

There may be involvement of the rectosigmoid

1:27

colon or the posterior cul-de-sac, and

1:30

then we might have involvement of the

1:31

round ligament or surgical scars as well.

1:34

So those are all manifestations

1:36

of the deep infiltrating type.

1:39

So what do you look for on MRI when

1:41

you're evaluating pattern three?

1:43

Well, one of the manifestations is the

1:46

presence of a solid or a fibrotic mass.

1:49

So these actually are quite common,

1:51

but unless we're looking for

1:53

them, we can easily overlook them.

1:55

So if you didn't know to look behind the

1:57

uterus, when evaluating a patient with

2:00

endometriosis, you might miss this area of

2:03

scarring or soft tissue thickening right in

2:06

the midline along the posterior cul-de-sac.

2:09

And it's quite challenging because you're

2:10

looking for a structure with low T2 signal,

2:14

which is the scarring that's adjacent to other

2:17

structures with intermediate or low T2 signal.

2:20

So very challenging to

2:23

identify, certainly not easy.

2:25

You really have to look for.

2:27

A difference in shape or a little

2:28

bit of distortion or indrawing of

2:31

the structures towards the midline to

2:34

find that particularly in this case.

2:36

And again, just a reminder that with

2:38

this deep endometriosis, we've got

2:41

the deposits that are embedded within

2:43

dense fibrous tissue and sometimes

2:45

even smooth muscle, depending

2:46

on which organs are involved.

2:48

So remember to start your search with the

2:50

ovaries and then sort of look superficially and

2:53

then look deep posterior in all the organs.

2:55

And then you're, you're doing

2:57

due diligence to the case.

2:59

So earlier I mentioned frozen cul-de-sac.

3:02

So here's some images from AJR, just

3:05

showing a 27-year-old woman who had

3:07

posterior cul-de-sac endometriosis.

3:10

And this was a dynamic examination that

3:13

was done with transvaginal sonography.

3:16

So here we can see some nice gut signature.

3:18

So this is the rectum here with the variable

3:21

layers in transverse and in longitudinal, and

3:24

then we've got this structure that's annotated

3:26

by the asterisk, it's got some flow around it.

3:30

And that's preventing mobility

3:32

of the uterus, which is anterior.

3:34

So this is positioned between the anterior

3:36

rectal wall and the posterior uterine

3:38

wall, and then we're not seeing sliding

3:40

of the uterus anterior to the rectum.

3:43

So that's what the frozen cul-de-sac

3:44

looks like on sonography.

3:47

But again, it has to be done dynamically.