0:02

Hello, and welcome to Noon Conference, hosted by

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Modality. Noon Conference connects the global radiology

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community through free, live educational webinars that are accessible for

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all, and is an opportunity to learn alongside top radiologists from around the

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world. Today, we're honored to welcome Dr.

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Erin Gomez for a lecture entitled, "MR Evaluation of the

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Female Perineum." Dr. Gomez is an assistant professor of

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radiology and the director of diagnostic radiology

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program at Johns Hopkins. Her academic

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interests include medical student and resident education,

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fundamentals and clinical applications of MRI physics, and

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cross-sectional imaging of the female pelvis, with a focus on high-risk

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OB imaging and MR evaluation of the placenta.

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At the end of the lecture, please join Dr.

0:51

Gomez in a Q&A session, where she will address questions you may have on

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today's topic. Please remember that-- to use the Q&A feature to submit

0:59

your questions, so we can get to as many as we can before our time is up.

1:02

With that, we're ready to begin today's lecture. Dr.

1:05

Gomez, please take it from here.

1:08

Thanks so much for the introduction, Ben.

1:10

I just want to confirm that you can see my screen and my pointer, and that you can

1:13

hear me okay?

1:15

Yep, we see and hear loud and clear.

1:18

Wonderful. Thanks so much for, um, coming to today's,

1:22

uh, Noon Conference. Today, we're gonna be talking about MR evaluation of

1:26

the clitoris and female perineum.

1:28

We're gonna walk through pearls and pitfalls in the imaging of this

1:31

very understudied region. And again, my name is Erin Gomez.

1:35

Um, I'm a radiologist at Johns Hopkins in Baltimore, and, uh,

1:39

female pelvis MR is really sort of a passion area for

1:42

me. I have no, uh, financial relationships to report,

1:46

and I won't be discussing any unlabeled or investiga-

1:49

investigational uses, um, of medical devices or pharmaceuticals

1:53

during this presentation. So let's walk through a little

1:57

bit of, uh, history here. When it comes to

2:01

imaging of the female perineum and vulva, there is

2:04

really, uh, a dearth of information and a relative

2:08

paucity of resources available to medical

2:12

imagers, and academicians in general, um, when it

2:16

comes to imaging of this region.

2:20

One of the great things about MRI for evaluation of the female

2:23

perineum is that it permits a high-resolution assessment of

2:27

vulvar pathology that we're not able to achieve with other

2:31

imaging modalities. And so by understanding the anatomy of

2:35

this region, abdominal radiologists can be much better

2:39

equipped to serve patients with injuries that may be related

2:42

to childbirth or perineal trauma, gynecologic

2:46

infection, and, of course, malignancy.

2:49

All of these conditions may require some sort of surgical

2:53

planning, and so understanding this anatomy also helps you craft a

2:56

report that can be helpful to not only the patient, but their

3:00

medical team, which may include a surgeon.

3:03

So the learning objectives for this talk are for me to

3:07

show you, and for you to understand, the normal imaging appearance of

3:11

the vulvar anatomy and perineum, which includes the

3:14

labia, the clitoris, um, including its components, the

3:18

crura, glands, and vestibular bulbs, as well as the female

3:21

urethra and the Bartholin glands.

3:24

And then, we're also going to review key imaging features of

3:28

various pathologies that affect the female external

3:30

genitalia. So I want to start with a

3:34

story of where this academic journey

3:37

began for me.

3:40

This is an MR exam that I was asked to read a couple

3:44

of years ago. It's for a twenty-three-year-old patient, um, with

3:47

dyspareunia, who was undergoing pelvic floor

3:51

physical therapy. And, um, so

3:55

dyspareunia is painful intercourse, and she had been going

3:59

to pelvic floor PT, uh, to try to address this, but,

4:03

um, it was not helping, and so her

4:06

provider, um, ordered this ultrasound.

4:09

Um, and on the color ultrasound images, we're

4:13

here at the level of the labia, and we can see,

4:17

um, this sort of bulky, hypoechoic tissue, um,

4:21

to either side of the midline, with some increased vascularity.

4:24

And this tissue looked much more prominent than we would expect to

4:28

see, um, in a normal labial ultrasound, and so

4:32

this patient was referred for MRI.

4:35

And so, um, here we have the MR images for this patient.

4:38

We have axial T2-weighted images here, and then

4:42

post-contrast, fat-saturated T1-weighted images of the

4:45

pelvis. And we can see, um, on either side

4:49

of the perineum, there's this area of kind of T2 heterogeneous

4:53

tissue, with these interspersed T2 hyperintense foci,

4:57

which look a lot like cystic change.

4:59

And then, this tissue enhances, um, somewhat

5:02

heterogeneously, uh, but consistently across

5:05

both sides. And so

5:08

when we were looking at this case in the reading room, it became very

5:12

clear that none of us were very familiar with the

5:16

anatomy, uh, that we were being asked to evaluate in this

5:19

region. And so we did what all

5:23

academic radiologists do best, and we went to the literature to

5:27

try to find some high-quality resources about

5:30

anatomy of the female perineum and external genitalia,

5:35

and unfortunately, there was almost nothing out there.

5:39

And so I went on a quest over to our medical

5:43

school and met with one of the anatomists, who works in

5:47

the cadaver lab and helps run the anatomy course for School of

5:50

Medicine at Hopkins. And long story short, the two of us did, uh,

5:54

several dissections together and are doing some imaging-related research

5:58

projects now to help clarify this anatomy, because what

6:02

you should know is that even in-...

6:05

the anatomic atlases and some of the resources that are out there,

6:09

the female anatomy is depicted with inaccurate

6:12

proportions and sometimes with anatomy that is just

6:15

presumed that it's a direct homologue of the male anatomy, which

6:19

is incorrect. And so, um, I've really sort of been on a

6:23

mission to clarify for as many radiologists as I

6:27

can make contact with,

6:29

to clarify this anatomy and to talk about what can go wrong in this

6:33

region. So back to this case. Um, so we eventually,

6:37

after lots and lots of digging, um, found that these are

6:41

the vestibular bulbs, and the cystic changes within them are, are

6:44

not what we would typically expect on medical imaging.

6:47

And so for us, um, we put forth a differential.

6:51

We said these could be complex Bartholin cysts,

6:54

or in the setting of this patient going to pelvic floor therapy, um, it

6:58

could be related to injections or manipulation of this

7:01

tissue. Um, but they did not biopsy this because the patient's symptoms got

7:05

better. But this is where it all began.

7:08

So let's take a deeper dive into the anatomy and

7:11

embryology, um, of the female perineum and

7:15

external genitalia. So the vascular supply to this region

7:19

comes from the internal pudendal artery, along with some branches of

7:23

the external pudendal. The innervation of this

7:27

region, particularly anterior vulva, is innervated by the

7:30

ilioinguinal nerve and the genitofemoral nerve, and then the posterior vulva

7:34

is innervated by perineal branches of the posterior cutaneous and pudendal

7:38

nerves. The lymphatic drainage of the vulva and

7:42

perineum is via the superficial inguinal nodal chain,

7:46

and then the clitoris and anterior labia minora may drain to the deep

7:50

inguinal lymph nodes or the external

7:52

iliacs. In terms of

7:55

embryology, um, I want to briefly highlight

7:58

common embry- uh, embryologic structures that are seen

8:02

during development, and then what they go on to develop into

8:07

in patients who are phenotypically female or male.

8:11

So the genital tubercle, tubercle, uh, begins out

8:15

embryologically, uh, undifferentiated, and in females, develops

8:19

into the clitoris, and in males, develops into the penis.

8:22

The urogenital folds become the labia minora in females

8:26

and the urethra in males. So we're already seeing sort of some

8:30

differentiation here anatomically.

8:32

And then the labial scrotal folds become the labia majora in females and the

8:36

scrotum in males. The urogenital sinus

8:39

becomes the Skene's and Bartholin glands in female patients and

8:43

becomes the prostate and bulbourethral glands in males.

8:48

So I'd like to now put on the screen for you our

8:52

suggested MRI protocol for evaluation of the vulva and

8:56

perineum in female patients. Um, one thing that we noticed

9:00

when we were reviewing papers or exams coming from the

9:03

outside

9:05

is that a lot of these, uh, patients, unfortunately, just

9:09

get lumped into a general female pro- pel- pelvis protocol

9:13

MRI, uh, which is really not gonna provide you with a small

9:16

field of view, high-resolution images of the external genitalia

9:20

that you need to perform if you are, um, interested in

9:24

evaluating some of these anatomic structures.

9:27

The other thing that I want to note is in some female pelvis MRI

9:31

protocols, the field of view actually excludes the perineum and

9:34

external genitalia because, uh, this exam is predominantly

9:38

focused on imaging the uterus and ovaries.

9:42

So field of view is critical. It has to be centered at the level of

9:46

the perineum. You want to start with sagittal, large field of view, T2 fat

9:50

sat, uh, images, similar to a female pelvis MR, and

9:54

then, um, also similarly to a standard female pelvis protocol MR, you want

9:58

to get large field of view, coronal, T2, non-fat sat

10:01

images, and an axial large field of view, T1 non-fat sat.

10:06

When we move into the small field of view images, again, this is focused at the

10:10

anatomic region of concern. You want to get axial and coronal

10:14

small field of view, fat saturated, T2 weighted

10:18

images. And these, um, fat saturated, T2

10:21

weighted, small field of view images are the ones that will give you

10:25

the highest resolution and best evaluation of the

10:29

clitoris and perineum. So this, if you remember

10:32

anything, this is the sequence that you absolutely need to be

10:36

performing for these patients.

10:38

Additionally, especially in patients who you think may have infection or

10:42

malignant involvement of this region, you want to do axial small field of view,

10:45

diffusion-weighted imaging with corresponding ADC maps, and then pre- and

10:49

post-contrast T1-weighted images in both the axial and sagittal

10:53

planes. Um, so let's do a bit of

10:57

an overview of the anatomy here, um, of some of the structures that we

11:01

are going to talk about in greater detail.

11:03

And I have a couple of medical illustrations that I want to walk

11:07

through, in addition to, um,

11:11

some MR images, uh, that will hopefully be instructive as

11:14

well. So we'll start at the midline.

11:17

The clitoris is made up of two crura, which are composed of erectile

11:21

tissue. They're called the corpora cavernosa, homologous to the male

11:24

anatomy, and these unite to form the body and glands of the

11:27

clitoris. Um, and so we can see the glands is here, this is the

11:31

body, and then these are the crura.

11:32

So these come together to form the body and glands.

11:35

The glands is homologous to the glands of the penis, and it's the only component of

11:39

the clitoris which is external. So the c- um, the crura of the clitoris

11:43

are deep to the ischiocavernosus muscle, and you will not see them

11:46

externally. The vestibular bulbs of the

11:50

clitoris are composed of, um, glandular tissue.

11:54

I'm sorry, this, uh, should say glandular, um, called

11:58

corpus spongiosum tissue, and they are deep to the

12:01

bulbospongiosus muscles and the labia

12:03

majora.... The Skene's glands, they are periurethral in

12:07

location, and they aid in urethral lubrication, and they are homologous to the

12:11

prostate gland, as we mentioned. And then the Bartholin glands aid in vaginal

12:15

lubrication. They are here. You see them down here just next to the vestibular

12:19

bulbs, and they're also deep to the bulbospongiosus muscles

12:23

and the labia majora. So this is a nice cartoon representation

12:27

of what this anatomy looks like. This is what it really looks like when you

12:31

put this in the hands of a capable, uh, medical

12:35

illustrator. Uh, this is something that we made as a team, and so very

12:38

cartoonish, um, but we had a medical illustrator come into the anatomy

12:42

lab with us, and I'd like to acknowledge the amazing work of Elise Butler,

12:46

um, who helped create this illustration for us.

12:49

But this is what this anatomy is going to look like, uh, in vivo

12:53

with a more accurate depiction. And so again, here are those

12:56

crura of the clitoris here. This is that erectile tissue, and

13:00

you can see when we cut that in cross-section, um, that kind of

13:04

spongy nature, and you can imagine with increased blood flow, this tissue is going

13:08

to engorge. This is the body and then the glands of the

13:11

clitoris, and I like this illustration because it also highlights

13:15

some of the neurovascular anatomy in this region.

13:18

Um, so we can see those pudendal nerve branches, which come in to

13:22

form, um, paired dorsal nerves of the clitoris,

13:26

and then, um, with much smaller branches, which supply the glands, uh,

13:30

of the clitoris. We can also see the

13:33

relationship, um, of the clitoris and, uh, both

13:37

glandular and erectile tissue to the symphysis pubis on this

13:41

cross-section. So the pubic symphysis is here.

13:44

One structure that I want to point out is the suspensory ligament

13:48

of the clitoris. You can see tissue both here as well as coming from above.

13:51

The suspensory ligament is analogous to, uh, a structure that is

13:55

also present, uh, in patients with a penis, and it

13:59

attaches the clitoris to the pubic

14:01

symphysis. One thing that I will note here

14:05

is that the neurovascular anatomy of this region is actually

14:10

incompletely mapped or is unknown.

14:14

So most anatomic atlases that exist today are

14:18

based on the dissection of one to two cadavers.

14:21

And so this is a good guess that we have from based on what we saw

14:24

in our cadaveric dissections, but there is almost certainly

14:28

variation in the neurovascular supply to this region, um, which

14:32

requires further exploration with more detailed studies like MR

14:35

neurography. This is what this region

14:39

looks like on, um, T2-weighted MR images of the

14:43

pelvis. And so we have an axial and a sagittal T2-weighted image of

14:47

the pelvis. These are larger field of view images, uh, but they still

14:51

get the job done. We can see the crura of the

14:55

clitoris out here on the side. We can also see the body and the

14:59

glands of the cl- the clitoris. This is the urethra.

15:02

We can see it coming down from the bladder neck.

15:04

This is the level of the vaginal introitus, and then here are the vestibular

15:08

bulbs. These are gonna look hyperintense or intermediate on T2-weighted

15:12

imaging.

15:14

So now let's move into some cases. This is a sixty-eight-year-old woman

15:18

who presented with clitoral enlargement, and so MRI was

15:22

performed. Um, we can see axial and

15:26

sagittal T2-weighted images here, which demonstrate this

15:30

really well-circumscribed, ovoid, T2

15:33

hyperintense cystic lesion, which we see at the red arrow here.

15:37

It's located inferior and slightly anterior

15:41

to the glands of the clitoris, which we can see at this purple

15:45

arrow. We also did post-contrast T1-weighted

15:49

images, um, and you can see that this structure demonstrates

15:53

significant rim enhancement and then diffuse

15:56

diffusion restriction. And so this ended up being a clitoral

16:00

hood abscess. Um, this patient underwent drainage

16:04

and felt much better.

16:07

So this is a nice segue into talking about

16:10

clitoromegaly. Um, so clitoromegaly is enlargement

16:14

of the clitoris, which can be congenital or acquired, and if

16:18

congenital, the most common cause of this is congenital adrenal

16:21

hyperplasia, or CAH. Patients with

16:25

congenital adrenal hyperplasia, um, will not only have

16:29

clitoromegaly, but they'll also have other features, um, of

16:32

ambiguous genitalia and virilization.

16:35

And so, um, acquired causes of clitoromegaly

16:39

include medication side effects, such as those used for,

16:42

um, gender-affirming care in trans men, as well as patients

16:46

with PCOS. And then additional conditions which can

16:50

cause either real or apparent enlargement of the clitoris, um, include

16:54

clitoral abscesses, as we just showed, or

16:57

cysts. So this is a nice companion case.

17:00

Um, this is a patient with a history of vulvar cancer,

17:04

and she's undergoing follow-up imaging, um, to see if she

17:08

has any evidence of recurrent disease.

17:11

And so we have a coronal, um,

17:15

and axial here, T2-weighted image of the, the female pelvis at the

17:19

level of the perineum. On the coronal, we see the uterus in cross-section here on

17:23

top of the urinary bladder. And the

17:27

initial read for this was a hypointense midline

17:31

vulvar lesion, which we can outline here.

17:34

Um, it's also here on the axial T2-weighted image, and

17:38

then this demonstrated significant enhancement on sagittal

17:41

post-contrast imaging. So concern was raised

17:45

for potentially a midline recurrence of the patient's vulvar

17:49

cancer. Um, however, uh, when this patient underwent

17:53

physical examination, um, and was even initially evaluated

17:56

for biopsy, this was confirmed to represent the normal clitoris.

18:00

So this is a nice opportunity to show, um, the way that the distal

18:04

aspect of the crura may look on coronal imaging, coming together to form the

18:08

body and then the glands. So this is just a patient, uh, with a slightly

18:12

larger, uh, glands clitoris relative to, um,

18:16

other patients that this radiologist had seen previously.

18:19

And so the pearl for this case is to remember-...

18:22

that there can be significant variation in the normal appearance and

18:26

size of the clitoris, um, as we see, uh,

18:29

homologously in male patients. So now let's talk

18:33

more about congenital adrenal hyperplasia.

18:36

This is a group of congenital disorders characterized by

18:39

deficiencies of enzymes involved in adrenocortical steroid

18:43

production, and this commonly results in an excess of

18:46

androgens. So that excess androgen, uh,

18:50

manifests as virilization in ambiguous genitalia in

18:54

female patients. There are two major subtypes that exist.

18:58

This is the cla-- the classic form, which presents at birth,

19:02

and then the non-classic form, which presents later in

19:05

life. And so, um, we can use the

19:09

Prader scale, uh, to help us

19:12

classify patients with congenital adrenal hyperplasia.

19:16

So this was developed specifically for XX infants

19:20

affected by congenital adrenal hyperplasia.

19:22

And so the Prader scale, um, systematically uses features

19:26

like the clitoral phallic length and the degree of labial scrotal

19:30

fold fusion to describe the degree of

19:34

virilization present in this patient

19:36

population. So this is an example of a patient with

19:40

congenital adrenal hyperplasia.

19:42

This is a nine-month-old female with CAH, and so

19:47

we have axial and sagittal T2-weighted images of the

19:50

pelvis. This is also axial here, um, demonstrating

19:54

ambiguous genitalia. We can see externally, um, there

19:58

is soft tissue, which, uh, maybe looks like it could represent

20:01

labia, um, as well as clitoromegaly and

20:05

a virilized appearance of the clitoris.

20:08

We can see that the crura of the clitoris, um, and

20:12

the, uh, body of the clitoris and glans have a much more

20:16

phallic appearance, and this patient demonstrated

20:20

Prader four anatomy with complete fusion of the labia

20:23

majora, and then, um, a common channel urogenital

20:27

sinus, which we can see here at the orange arrow.

20:30

So we don't see typical, um, uterine

20:34

anatomy for this patient.

20:37

Okay, uh, I showed you this case earlier, so we'll skip that.

20:41

Let's move on to talk about vulvar cancer.

20:44

Vulvar cancer is very rare, but it represents the fourth

20:48

most common gynecologic cancer, and the vast majority of patients

20:52

who have a vulvar cancer are going to have a squamous cell

20:55

carcinoma. Second to this is melanoma.

20:59

So vulvar cancers usually spread by direct extension to

21:02

adjacent structures. They can spread to the vagina, the urethra, and

21:06

anus, as well as through the lymphatics.

21:09

And as we talked about earlier, vulvar cancers are going to

21:12

go most commonly to those superficial inguinal nodal

21:16

chain nodes, um, as well as sometimes

21:20

the deep inguinal and external iliac lymph nodes.

21:22

So as long as you're looking in that kind of anterior and external

21:26

pelvic nodal chain when you're evaluating these patients, which is why we do

21:30

those larger field-of-view images, um, in the MR imaging

21:34

protocol, you're gonna be appropriately evaluating for nodal metastatic disease

21:38

in this patient population. So vulvar squamous cell

21:42

carcinoma, um, it will have intermediate T2 signal intensity on

21:46

MRI and a variable enhancement pattern on post-contrast

21:50

imaging. The number of lymph nodes present at the

21:53

time of diagnosis, excuse me, has a significant impact on

21:57

prognosis for these patients, as well as the risk of distant hemo-

22:01

hematogenous disease. And so it's

22:05

really important when we're characterizing MR imaging for

22:09

patients, um, with a vulvar cancer, to talk, um, in

22:13

as much detail as possible about the degree of local invasion,

22:17

as well as suspected nodal st- metastatic disease, because

22:21

this can, um, sometimes take surgical resection off the table

22:25

for the patient. Other less common

22:28

malignant entities that can involve the vulva include

22:32

sarcomas, uh, non-mammary Paget's disease, and then carcinomas of the

22:36

Bartholin glands, which are extremely rare.

22:39

So this is a patient with a vulvar squamous carcinoma.

22:43

This is a sixty-four-year-old woman, and she came into the

22:47

clinic with a visibly ulcerated and erosive vulvar lesion, and

22:51

so MRI was performed for further evaluation.

22:54

And, um, this is-- sorry, I lost my arrow here for some

22:58

reason. Um, but this is the midline vulvar

23:02

mass. We can see it here on the T2 weighted imaging, and it really has

23:05

that, uh, sort of evil gray appearance that we see with a

23:10

lot of tumors on T2 weighted imaging.

23:13

If you think about the way that like an HCC or

23:15

cholangiocarcinoma would look in the liver, it's that same sort of

23:19

ill-defined T2 intermediate, um, appearance to this

23:24

well-circumscribed midline vulvar lesion here.

23:27

And we can see a component of the lesion extends here, um, along the

23:31

right greater than left midline. On the

23:34

diffusion-weighted images, there's intense diffusion restriction

23:38

within this lesion. And then on the post-contrast images, it's

23:42

very heterogeneously enhancing, and we can see a component of

23:45

this lesion at the level of the perineum as well.

23:49

Um, and so this was a biopsy-confirmed diagnosis of

23:53

squamous cell carcinoma. Next, let's talk

23:57

about vulvar melanoma. So this specifically refers to a

24:00

subset of melanoma called mucosal melanomas.

24:04

Um, we think about sort of dermal melanomas, uh, that we see

24:08

typically in our patient populations.

24:10

Um, but when melanoma goes on to involve the

24:13

vulva, uh, this is a mucosal melanoma, and so these can affect the

24:17

labia minora, the clitoris, the inner labia majora, the

24:21

vaginal introitus, and then even the mucosa of the periurethral

24:25

tissues.... melanomas of the skin of

24:29

the mons pubis or the outer labia majora appear and present

24:33

just like cutaneous melanomas in other locations.

24:37

Um, and so vulvar melanomas will present with pigmented, or in some

24:41

cases, amelanotic or red lesions.

24:44

They can cause irritation, pruritus, um, these patients can also present with

24:48

pain and bleeding, so it's a very uncomfortable condition for patients to

24:52

have. MRI will de- um, demonstrate

24:55

an enhancing mass with associated diffusion restriction.

24:59

Um, and so everybody thinks of melanoma as being

25:02

intrinsically, um, T1 hyperintense.

25:06

Um, but for patients with a vulvar melanoma, like, sometimes

25:10

you will see that, uh, but the T1 and T2 appearance will vary depending

25:14

on how much melanin is present. So highly melanotic

25:17

lesions will demonstrate that t- intrinsic T1

25:21

hyperintensity, uh, because of those paramagnetic properties of

25:24

melanin. So this is a patient

25:28

with a vaginal melanoma, sixty-four-year-old woman.

25:31

Um, she had pelvic MRI for further evaluation, and so

25:35

we have axial T2 weighted images at the level of

25:39

the perineum. Um, we can see there's this mass centered

25:43

at the level of the vaginal introitus.

25:45

It has this very T2 intermediate heterogeneous

25:49

appearance to it, and we can also see that this lesion,

25:53

um, encircles the urethra, which is

25:56

here. This is a T1 pre and a

26:00

T1 post-contrast image at the same level, and we can

26:04

see for this lesion, this is a highly melanotic lesion because it

26:07

demonstrates multiple foci of intrinsic T1

26:11

hyperintensity. And then on this subtracted

26:14

post-contrast image, we can see there's a lot of enhancement within

26:18

this lesion, and so this is a path proven case of vulvar

26:21

melanoma.

26:24

Next case, this is a patient with perineal pain.

26:27

Uh, she has a history of Crohn's disease, and so, um,

26:32

they were, uh, suspecting some complication of Crohn's just because

26:36

the degree of perineal pain that the patient was presenting with.

26:40

Um, so this forty-eight-year-old woman, um, came in for follow-up for Crohn's

26:44

with MRI. We have coronal and then sagittal

26:47

T2 weighted images of the pelvis. And when we look at the

26:51

perineum here, we can see that these tissues, they just look

26:55

thick, right? There is a lot of what we call induration

26:59

or, um,

27:01

edema and suspected firmness of this tissue,

27:05

both here at the level of the perineum, um, on the coronal,

27:09

as well as the sagittal images. Um, things just look already

27:13

very abnormal in this region. It looks like a lot of inflammation

27:17

has been occurring here. We can see this just kind of like spiculated T2

27:21

hyperintense appearance. And so this patient, um, received

27:25

contrast. This is the post-contrast image at the level of the

27:29

external genitalia. We can see how thickened and abnormal

27:33

appearing the labia are. Um, and then there's

27:36

also, um, multiple small, um, well-circumscribed

27:40

regions of enhancement. And so, um,

27:44

these are exit sites of a peri-anal

27:48

fistula extending to the labia in this patient with

27:51

Crohn's disease. So a pearl for this case that I want

27:55

you to remember is that local, regional, infectious, and

27:59

inflammatory etiologies, such as stigmata of inflammatory bowel

28:03

disease, may also involve the labia.

28:05

So not all labial soft tissue induration and

28:09

enhancement is malignant, and you have to use the patient's clinical history

28:13

to guide your interpretation of the

28:15

imaging. Next case, this is a

28:19

patient, uh, an elderly woman who presented with a

28:23

bulbar mass. She was seventy-one years old.

28:25

I remember seeing, uh, this patient on the ultrasound service, and

28:29

she had a palpable labial mass, and, um, she told me that it

28:33

had been slowly enlarging over a period of months.

28:38

Um, it was not red, uh, or

28:41

particularly painful to the touch, but she noticed it

28:44

was there, and it was definitely something that she had not observed

28:48

previously.

28:51

So we went in, uh, to perform the ultrasound.

28:54

We can see, um, these are our midline soft tissue, uh,

28:58

grayscale images of the labia. We can see that there are these

29:01

well-circumscribed, hypoechoic lesions to the right and

29:05

left of midline. When we take a look more

29:09

closely, um, at one of these masses, uh, we

29:13

can see that there's this very fine, sand-like,

29:17

heterogeneous, hypoechoic appearance of the internal aspect

29:21

of this lesion, with big feeder vessels coming into the

29:24

periphery. Similarly, when we look at the left

29:28

labia near the vaginal introitus,

29:31

we can see these really engorged, um, very

29:34

prominent vessels extending not only into the, uh, around the

29:38

periphery of this lesion, but some leading directly into it.

29:42

And when we, um, observed,

29:46

uh, dynamically these lesions, there was very

29:50

slow, subtle flow internally on cine imaging, uh, which

29:53

unfortunately I don't have for you today.

29:56

But these ended up being labial varices.

29:59

So labial varices are something that, um, we most often see in

30:03

the context of pregnancy. Labial varices typically

30:07

occur in patients who are in the second or third trimester of a

30:10

pregnancy, uh, secondary to venous stasis related to

30:14

compression of the pelvic venous vasculature by the gravid uterus.

30:18

And so most often, patients who present with labial varices are

30:22

younger, and the treatment for this is delivery, and these will resolve after the

30:26

patient is no longer pregnant....

30:27

but in an older patient, um, we were more concerned that these

30:31

varices could be the result of upstream

30:35

compression of the, uh, venous vasculature of her

30:38

pelvis, perhaps by some kind of mass or, um,

30:43

big, bulky adenopathy. Um, so the patient

30:47

underwent a CT of the abdomen and pelvis, which ended up being normal,

30:50

thank goodness. Um, and the patient, uh, underwent a

30:54

venous embolization with interre-- inter, um, interventional

30:58

radiology, with resolution of both the lesions and her

31:02

symptoms. So this was a case of benign labial varices in the setting

31:06

of, um, venous incompetence and venous stasis.

31:11

Next case, this is a patient with a painful left vulvar

31:14

mass. Um, MR imaging of the pelvis was performed, and we see

31:18

this very T2 hyperintense, ovoid

31:22

lesion at the level of the external genitalia.

31:25

It's hypointense on T1 weighted imaging, and when

31:29

we give contrast, this thing really, really enhances.

31:33

This T1 post-contrast image looks almost as bright as

31:37

the T2 weighted image.

31:39

We also have coronal and sagittal, um,

31:43

images of the pelvis, and we can see that this lesion

31:47

is very T2 hyperintense and then maintains that degree of enhancement on the

31:51

post-cons. Um, it was very challenging

31:55

to tell what this was prospectively, and I don't know that you

31:59

can call these lesions prospectively, just given the potential

32:02

for this to be a malignant entity. Um, but because,

32:06

uh, they, um,

32:09

they tried multiple times in the office to resect this lesion and were

32:13

unable to, the patient underwent a radical left

32:16

vulvectomy, and pathology confirmed a diagnosis of

32:20

sinusoidal variant vulvar hemangioma.

32:23

I suspect this is the only case of this I will ever see in my

32:26

lifetime.

32:29

Let's move on to Bartholin gland cysts.

32:31

Um, so the Bartholin glands, these are small glands

32:36

located in the posterolateral aspect of the vagina bilaterally.

32:39

And again, as we mentioned at the beginning of the talk, um, these are

32:43

responsible for lubricating the vagina, and so they are

32:47

lined by columnar epithelium. Um,

32:51

inflammation or infection of the Bartholin glands can

32:54

result in obstruction of the ducts that lead out of

32:58

them, and you can get Bartholin gland cysts.

33:01

So you won't see the Bartholin glands unless there is a problem

33:05

with them. These cysts often we discover

33:08

incidentally on medical imaging, um, but they can

33:12

become super infected, and very rarely, as I mentioned

33:16

earlier, uh, they can have neoplasms that arise within them, but this

33:19

is e-exceptionally rare. So classically, Bartholin gland

33:23

cysts are T2 hyperintense cystic lesions.

33:26

We can see, uh, bilateral Bartholin gland cysts on this

33:29

axial fat-saturated T2 weighted image of the pelvis.

33:33

Uh, here's a coronal view for the same patient.

33:36

And then on the post-contrast image, uh, we can see that there's no

33:39

enhancement within this lesion and that it is centered,

33:43

um, within the posterolateral aspect of the vagina.

33:47

So, um, again, these are gonna be unilocular.

33:50

They're often, um, on either side of the vagina,

33:54

posteriorly and laterally. They're gonna be medial to the labia

33:57

minora and at or below the level of the symphysis

34:01

pubis. So the symphysis pubis is here on this sagittal image of the

34:05

pelvis, post-- T1 post. Symphysis pubis is

34:09

here, and then the Bartholin's gland is below the level of

34:12

this. So, um, that's the pearl here.

34:15

It's a mnemonic that you can use to help yourself remember, is that Bartholins

34:19

are below the symphysis

34:20

pubis. Here's another patient who had a

34:24

vaginal cyst on physical exam. Um, so this was a

34:28

sixty-eight-year-old patient. She had a history of stage

34:31

IIIC, grade three endometrial cancer,

34:35

and when she came into, uh, her gynecologist's

34:39

office, um, she felt a palpable lesion, and

34:43

the gynecologist felt this as well.

34:45

They suspected a Bartholin gland cyst for this person,

34:49

um, but they ordered an MRI for further characterization, just given

34:53

her history of malignancy. So here are

34:57

the axial T2 weighted images. We also have a

35:00

post-contrast T1 weighted image, and then we have a

35:04

diffusion weighted imaging and a corresponding ADC

35:07

map. And so we can see that this is really not a cystic

35:11

lesion, um, in the way that the other Bartholin gland cysts that

35:15

we showed are. Uh, this is a much more complex-looking

35:19

lesion. It has a small cystic component centrally,

35:24

and on the post-contrast images, this has a very thick,

35:28

solid-appearing, uh, component to it with peripheral

35:31

enhancement. And then on the diffusion-weighted image and the corresponding

35:35

ADC map, this is really, really bright with corresponding ADC dark

35:39

tissue, so this is avidly restricting.

35:42

This is definitely not a Bartholin gland cyst, and, uh, this was

35:46

biopsied and was confirmed as recurrent endometrial

35:49

cancer. I see there are a couple of comments in the chat, so

35:53

I'm just gonna take a peek at those.

35:55

Uh, okay, I see there was a, a guess at the, the pathology.

35:59

Okay.

36:01

So next, let's talk about the female urethra.

36:04

The female urethra is short, much shorter than the male urethra.

36:08

It's about three centimeters in length, and it extends from the bladder to the

36:11

external urethral meatus, which is located in the vestibule.

36:15

The proximal one-third of the female urethra, and when I say

36:19

proximal, I mean closest to the urinary bladder, is lined by

36:23

urothelium. And then the distal two-thirds of the female urethra,

36:27

meaning on the way to the external urethral meatus, is

36:31

squamous epithelium.... And so the urethra will have

36:35

a trilaminar appearance on MRI.

36:40

Urethral diverticula are the most common pathology that you will

36:44

see, um, involving the female urethra.

36:46

These are projections of the urethra into the surrounding

36:50

fascia. Um, they are true diverticula with an

36:53

epithelial lining that is identical to the urethral mucosa.

36:57

And the symptoms of urethral diverticula are very

37:00

nonspecific, um, but the classic teaching

37:04

describes a triad of dysuria, so painful urination,

37:08

dyspareunia, painful intercourse, and then post-void

37:11

dribbling. And on T2-weighted imaging of the

37:15

pelvis, these diverticula will look hyperintense because they're

37:19

filled with urine, uh, but they can vary in signal if they get

37:23

proteinaceous debris or hemorrhagic contents within

37:26

them. And there are lots of different configurations

37:30

of urethral diverticula. I'll show you a couple classic

37:33

configurations. Um, as you can imagine, these can

37:37

certainly get infected because you have urinary stasis within

37:40

these. Um, they can develop calculi if there's

37:44

precipitation within them, and of course, they can also develop

37:48

neoplasms, the most common of which is a clear cell

37:51

adenocarcinoma. So this is a patient

37:55

with a urethral diverticulum, it's a seventy-one-year-old.

37:59

She was undergoing an abdominopelvic CT for

38:02

suspected diverticulitis. And so we have axial

38:06

CT images, coronal, and then sagittal CT images of the

38:10

pelvis. We see this bilobed cystic structure

38:14

here. Here it is on the coronal. Here it is on the sagittal.

38:18

We can see it sort of, um, just below the level of the bladder neck, and the

38:22

proximal urethra is here.

38:24

It's arising from the female urethra, um, and we can see

38:29

a small out-pouching, um, along the anterior

38:32

urethra communicating with this lesion.

38:35

We can also see it here, this little nubbin coming out, uh,

38:39

communicating with the lesion. So this

38:42

configuration of urethral diverticulum that like

38:45

drapes over the urethra like this, it's referred to as a

38:49

saddlebag urethral diverticulum.

38:52

I don't know if you guys know what saddlebags are, but they're basically like bags

38:55

that you drape over, like, a horse or, like, a, a pack

38:59

mule, um, to carry along. And so the fact that the

39:03

diverticulum straddles the urethra like this, they call it a saddlebag

39:06

diverticulum. Um, there are also, like I said, lots

39:10

of different configurations of these.

39:11

You can see them look like a unilocular out-pouching.

39:15

Some of them will look like a four-leaf or three-leaf clover.

39:19

Um, so if you see something that looks like a fluid-filled projection coming off of

39:22

the urethra, you should definitely suggest this.

39:26

Urethral cancer is a really rare entity.

39:30

Um, risk factors for urethral malignancy include

39:34

chronic inflammation, like chronic urinary tract

39:37

infections, HPV, leukoplakia, and of course, urethral

39:41

diverticula. So the most common malignancy to involve the

39:44

urethra is urothelial carcinoma proximally, right, and

39:48

then squamous cell carcinoma distally.

39:51

The urethra, of course, can also be sort of a second

39:54

victim and be involved or invaded by vaginal or

39:58

perineal tumors. So here's a case of that.

40:02

Um, this is a person with cervical cancer, a

40:06

fifty-two-year-old. Uh, so history of cervical cancer.

40:08

She had had chemoradiation. She presented with

40:12

vaginal pain and bleeding. And so here is our

40:16

sagittal and axial T2-weighted images of the pelvis, and

40:20

we can see-- so, uh, we have, um, looks like either a remnant uterus or

40:23

cervix up here. There's a big, uh,

40:27

irregular T2 hypointense mass, right?

40:30

We can see that the cervix is really thickened and

40:34

hypoenhancing, uh, sort of hypo-- uh, sorry, hypointense on these

40:37

T2-weighted images. Um,

40:41

and when we come down to the level of the

40:44

urethra, we can see all of this tumor extends along the neck of

40:48

the bladder. There's a very irregular appearance of the bladder neck and

40:52

then the proximal urethra here. And so, um, we

40:56

can see this soft tissue, this T2 hypointense

41:00

soft tissue, extending circumferentially around the

41:04

urethra. Um, we can see this here as well on the

41:07

post-contrast images. And so this patient underwent biopsy of this,

41:11

and this was recurrent, poorly differentiated, invasive squamous

41:15

cell carcinoma of the cervix, but involving the urethra as

41:19

well. Next, we'll move on and talk

41:23

about, since we're sort of in the urethral and periurethral

41:26

region, we'll talk about Skene's gland cysts.

41:29

So the Skene's glands or periurethral glands, these are a group of small

41:33

glands that lubricate the urethra near the external urethral

41:37

meatus, and the Skene's duct cysts are

41:41

retention cysts caused by inflammatory obstruction of the

41:45

periurethral ducts, very similar to the Bartholin gland cysts, right?

41:48

And sort of

41:50

cysts involving the, uh, uro-- genitourinary

41:53

tract in general, we can think of as, like, related to obstruction or inflammation.

41:57

Both the insert, uh, cysts in the cervix are mucus retention

42:01

cysts, and then Skene's and Gardner and Bartholin gland

42:05

cysts, um, are all sort of related to, um,

42:09

retention caused by inflammatory obstruction.

42:12

So on imaging, Skene's gland cysts are gonna look like rounded

42:16

or oval-shaped T2 hyperintense lesions.

42:19

They're gonna be lateral to the urethral meatus and

42:22

inferior to the symphysis pubis. And so they

42:26

can be really difficult to distinguish from Bartholin gland cysts.

42:30

Sometimes it can-- depending on how intimately

42:34

associated these are with the urethra, they can also be challenging

42:38

to distinguish from urethral diverticula, but the small

42:42

size, lateral location, and unilocular appearance can allow you

42:46

to suggest a Skene's gland cyst rather than a urethral

42:49

diverticulum.... Okay, I

42:53

think that's what I just said. Yeah.

42:55

Um, and then urethral cysts are maybe bo- more

42:58

posterior in location, uh, but the Skene's gland cysts will be

43:02

lateralized.

43:04

So to summarize, um,

43:07

vulvar anatomy and pathology, particularly that of the

43:11

clitoris and external genitalia, is a really understudied area in

43:14

medicine, especially compared to the wealth of literature and

43:18

research that's dedicated to male body anatomy and pathology.

43:23

MRI provides us with an amazing opportunity to obtain

43:26

high-resolution assessments of the vulva and associated pathology, and

43:30

this allows radiologists to address a significant need

43:34

within the population of patients that has this anatomy.

43:37

And so becoming familiar with these structures is gonna

43:41

help you identify what's normal, so that you're not calling something

43:45

normal abnormal, but also allows you to detect and describe

43:49

pathology, including staging of malignancy for these patients, which

43:53

is super important. So with that, I would like to thank

43:57

you for your time and attention. Here is my contact

44:00

information, um, if you'd like to reach out to me after the lecture.

44:04

I have both my institutional email, as well as my, uh,

44:08

Twitter, and then here are my references for this talk.

44:12

Um, so with that, I will open the floor for questions.

44:16

Um, I'd be happy to take any that you have.

44:18

Looks like we have one in the chat here.

44:21

Uh, okay, this is, uh, just, uh, coming from the modality team.

44:25

Let's see, I think I see another one here in the Q&A off to the

44:28

side.

44:32

Okay.

44:37

Okay, so, um, let's see. So the first one says: "Can you please

44:41

explain the anatomic difference of the female external anal

44:44

sphincter with that of the male?" Um, so

44:49

I-- to my knowledge, there's not a difference in

44:53

the anal anatomy between male and female patients.

44:57

Um, if somebody, uh, in the chat has other information, please correct me

45:01

if I'm wrong, but it's my understanding that the GI tract anatomy,

45:04

um, as long as there is no,

45:08

uh, sort of variant, um,

45:12

developmental anomaly there, that, um, everything should be the

45:16

same. Uh, okay, let's see. Somebody in the

45:20

chat also said: "Can you please enumerate the MR protocol sequences for

45:24

an MRI, um, female, uh,

45:27

perineum examination?" So let's go back to that slide.

45:30

I'd be happy to review that with you again.

45:36

I'm sorry, you guys, I have a, a little bit of a cold today, so I

45:39

apologize for my voice being a little, uh, squeakier than

45:42

usual. So this is our suggested MRI protocol.

45:45

This is our institutional protocol at Johns Hopkins.

45:49

Um, so these large field of view images are gonna be your

45:53

standard female pelvis MRI protocol.

45:56

So sagittal fat-saturated T2-weighted images.

45:59

You're gonna do a coronal non-fat sat, large field of view

46:03

T2. And by large field of view, I mean, um, encompassing the

46:07

entire female pelvis, right? So pelvic brim to the level of the

46:10

perineum. Next, you're gonna do an axial large field of

46:14

view T1 non-fat saturated image. And then,

46:18

when we're looking specifically at the vulva and

46:21

perineum, you wanna get small field of view, axial

46:25

and coronal T2 fat-saturated images.

46:29

These are the images that are going to allow you, um, to

46:32

visualize, uh, the anatomy of the clitoris and vestibular

46:36

bulbs. This fat-saturated, small field of view,

46:39

T2-weighted imaging is also going to allow you

46:43

to see that T2 intermediate signal in

46:46

cancers, um, of the vulva and

46:49

perineum. In order to characterize malignancy or

46:53

infected structures in this region, you also wanna do those axial small field of

46:57

view, diffusion-weighted images with a corresponding ADC map.

47:00

And then, to characterize degree of enhancement and vascularity, you wanna

47:04

do axial and sagittal pre- and post-contrast T1-weighted

47:08

images. I hope that helps answer your question.

47:12

Okay, let's go to more Q&A.

47:16

Uh, let's see.

47:19

Um, somebody said: "Can you, uh, revise the anatomy

47:23

of the vulva on MRI images?" Do you mean review?

47:26

Do you want me to go back and go over that again?

47:29

Um, if you could just clarify, let me know, and then I'd be happy to go back and

47:33

show that again.

47:36

Um, the next, uh, person said: "For basic protocols,

47:40

would you recommend standard coronal T2 or coronal oblique

47:44

adjusted to the vaginal canal to better interpret anal sphincter

47:47

involvement in vulvar or vaginal cancers?" That's a good

47:51

question. You know, it's interesting, um,

47:53

some of this protocol that we use for evaluation of the vulva was

47:57

adapted from our perianal fistula protocol that

48:01

we already use for patients with, um,

48:05

inflammatory bowel disease. And so, um, I don't know

48:10

that an oblique, um, image is

48:13

necessarily required. Um, as long as you are

48:17

able to see the internal and external

48:20

sphincters, um, with a degree of confidence, uh, then you

48:24

can-- um, you should be able to, to

48:27

follow, uh, any tumor to see involvement of the anal

48:31

sphincter. Um, okay, I think the person was asking for a review of the

48:35

vulvar anatomy slide. So let's go back to

48:38

those.

48:40

Okay, um, so let's review on imaging

48:44

here. So we have axial and sagittal, and, and as I said, um, you know,

48:49

we were really, like, searching our imaging

48:52

archives for-... um, vulvar

48:56

exams that had been protocoled correctly.

48:59

So unfortunately, I don't have a small field of view, um,

49:03

like historical image from when I was making this talk, uh, of the vulva.

49:06

But let's just go through everything, um, in a little more detail

49:10

here. So these are the pubic rami here, right?

49:14

And then medial to that, you're gonna see the crura of the

49:18

clitoris. You'll also see the vestibular bulbs.

49:21

The crura of the clitoris will come together, and we don't see the glans on

49:25

this axial image, but we can see the glans here, and then this

49:29

is the body of the clitoris. You can see how intimately

49:33

associated these structures are with the urethra, as

49:37

well as the level of the vaginal introitus.

49:41

I hope that answers your question.

49:44

Let's see. Looks like there's more.

49:48

Um, okay, this one says: What tips do you have in

49:51

localizing lower cervical and/or upper

49:54

vaginal masses when there is extension? This is a great question.

49:58

I love this question. So, um, one thing that can be

50:02

helpful in determining whether you're dealing with a true

50:06

primary vaginal cancer versus extension of a cervical cancer,

50:10

is the application of vaginal gel.

50:13

Um, we insert, um,

50:16

between thirty and fifty cc's of gel into the vagina

50:20

in

50:21

cases where we need to delineate whether it's a primary vaginal

50:25

lesion or, uh, extension of a cervical lesion.

50:29

And so, of course, if you're able to distend the fornices of the

50:33

vagina in particular, and, uh, decrease the apposition of the

50:37

vaginal walls by descending the lumen with gel, it may allow you

50:41

to discriminate between, um, sort of more localized

50:44

vaginal lesions, which are just abutting the cervix when everything is

50:48

collapsed, um, versus a true cervical lesion, which you'll see

50:52

in contiguity with, uh, either the anterior or posterior lip of the

50:56

cervix, and then extending along the fornix of the vagina.

50:59

I hope that answers your question.

51:02

I see a couple other, uh, just in the chat.

51:05

Um, so I see one that says: What imaging features help

51:09

differentiate a vulvar hemangioma from an AVM?

51:13

Um, this is a great question. So a vulvar hemangioma-- and, and some

51:17

of this has to do, um, with just an acknowledgment of the fact

51:21

that a lot of arteriovenous malformations that we

51:24

see, um, are c-- are congenital,

51:27

right? Vulvar hemangioma, um, is

51:30

something that I think is really hard to call

51:33

prospectively, but if we go back to the case

51:37

of the patient who had that vulvar hemangioma, um, it

51:41

does have classic features of,

51:45

um, of a hemangioma elsewhere,

51:49

right? It's a very T2 hyperintense lesion

51:53

with really rich, um, vascularity to it,

51:57

and, um, these are features that we see in hemangiomas elsewhere in the

52:01

body. I will say for an arteriovenous malformation, one

52:05

thing that could be helpful is doing a true MR

52:08

angiogram. Um, you may expect to see on the

52:12

standard T2-weighted images, um, more flow voids within a

52:16

lesion. That's an AVM. And if you do twist

52:19

sequences, which allow for arterial and venous phase

52:23

dynamic imaging, you may see

52:26

early filling of an arteriovenous malformation and then a draining

52:30

vein leading away. So if you really felt like you wanted to give it

52:34

a college try for differentiating between a hemangioma and a vulvar

52:37

AVM prospectively, I would recommend MR angiography

52:41

sequences to try to see if you can catch an early draining

52:45

vessel. I think that's the only tip that I would have for

52:48

that. These are great. Thank you so much for your amazing

52:51

questions.

52:54

Is there anything else?

52:58

Um, let's see. Somebody asked, um: Can you please show the anatomy

53:02

of the urethra and g- vagina? Sometimes it's hard to differentiate.

53:05

Let me see if I can go through any of these slides and see if we

53:09

have a good image where, uh, we show the

53:13

urethra relative to everything

53:17

else. Let me find one for you here.

53:22

And that's a good tip for me when I update this talk,

53:26

to show the relationship between

53:29

the external genitalia and the urethra in a little

53:33

bit more

53:34

detail.

53:37

We don't have the urethra in the field of view

53:39

here.

53:45

Maybe I'll come down to the

53:49

urethral... Uh, okay, so here's one that we can

53:53

see actually really nicely. So we are at the level of

53:57

the symphysis pubis in this patient who had that vaginal cyst, right?

54:01

So this is the urethra. It's gonna have that trilaminar

54:05

appearance, where the external portion of it is going to look very

54:09

dark. You're gonna have, um, a more T2

54:12

hyperintense or isointense rim centrally, and then you'll see the

54:16

lumen of the urethra, which is often collapsed.

54:19

And then back here, this is the vaginal introitus, and so

54:23

you'll see it posterior to the urethra.

54:25

The urethra kind of interposed between the urethra and then

54:29

the rest of the perineum, and sometimes, um, the anal sphincter will

54:33

also be in view here. So I apologize for not having,

54:37

like... And next time, maybe I should just put

54:40

a clip in here where we can kinda scroll up and down through that

54:44

anatomy and, and show everything in one

54:46

go.

54:49

Okay, I see another question. It says, um: Can you explain a

54:54

Skene's gland cyst again? Yeah. So the Skene's glands, they're paraurethral

54:57

glands. They are lateral to, um,

55:01

the, uh, urethra. And let's go back to that

55:05

first-...

55:08

slide. So the Skene's glands are here, right?

55:11

They're paired, teeny, tiny glands on either side of the urethra.

55:15

And so when you have a Skene's gland cyst, um, basically, so, so

55:19

these are glands that contribute to urethral lubrication, right?

55:23

And you often won't see them unless there's a problem.

55:26

But if there's obstruction of one or both of the Skene's

55:30

glands, you can see little cysts form within them, and the only way

55:34

you can tell the difference between a urethral cyst or a urethral diverticulum and

55:38

sort of hazard a guess at a Skene's gland cyst, is the fact that it's going to

55:42

be located lateral to the urethral

55:45

orifice. Um, those other structures will either have those classic

55:49

saddlebag or four-leaf clover configurations that urethral diverticula

55:52

have, or, um, a, a true urethral

55:56

cyst you may see more posterior in location.

56:00

Okay, um, let's see. There's another one that says, "Between the T2

56:03

hyperintense crura and vestibular bulbs on the MR

56:07

side, there is a T2 hyperinte- hypointense structure.

56:10

What is that?" Let's get there. These are great questions.

56:14

Thank you so much for all of the interactivity and

56:17

engagement with the talk.

56:20

Okay, uh, so are we here?

56:24

Is this what you're referring to? So

56:27

between... Or do you mean here?

56:31

Okay, this thing here, more

56:32

centrally?

56:38

Is this what you mean, this central structure? Yeah, so this is the...

56:41

Okay, yeah, so centrally, this is the vaginal introitus, okay?

56:45

So the vestibular bulbs, right, this is glandular tissue, so they are

56:48

going to, um, secrete and contribute

56:52

to vaginal lubrication. So this is the introitus here centrally.

56:56

And then out here laterally, remember that the vestibular

57:00

bulbs, as well as the crura of the clitoris, are covered by

57:03

musculature, right? We don't see them when we look at the external genitalia.

57:07

So this is some of that muscular tissue, the bulbo spongiosus

57:10

muscle, um, which is here along the, um, more

57:14

lateral aspect of the perineum. Does that make sense?

57:22

Okay, awesome. Let's see if there's anything else that came up in the

57:26

Q&A. Okay, uh, let's see. Um, one

57:30

person said, "What was the diagnosis on the first slide?" So, uh, the patient where

57:34

it all began. So we actually don't know.

57:38

Um, these were either u- complex, um,

57:42

Bartholin gland cysts, or what we figured out is

57:46

that as part of this patient's pelvic floor physical

57:48

therapy, she was getting Botox

57:51

injections, and so we wonder if this may be related

57:55

to the injection of Botox for her pelvic floor physical

57:59

therapy. Um, but they didn't end up biopsying this, so, um,

58:03

we never found out. But, um, I think it raised the

58:07

really, um, important point that nobody

58:10

knew at first what we were looking at here, and it sort of

58:14

triggered this deeper dive into, um, the dearth of

58:17

information about this anatomic region.

58:21

Um, well, I'll bring up the slide that has my email on it one more time,

58:25

and I would be happy to take other questions, um, by

58:29

email if you think of anything else after this CM or after this, uh,

58:33

presentation that you think, um, would be useful

58:37

for you. Sorry, I keep messing up my screen share.

58:39

Give me one second.

58:41

Awesome job, Dr. Gomez. Thank you so much for

58:45

your lecture today, and thanks to everyone who participated in this

58:49

noon conference and asked so many great questions.

58:53

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58:57

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59:00

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59:03

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59:07

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59:11

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59:15

on Chest CTA: Ancillary Physiologic

59:19

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