0:02

All right.

0:02

Thanks for joining us today.

0:04

Just wanted to say hello and welcome to the ninth of

0:06

many livestream noon conferences hosted by MRI Online.

0:10

In response to the changes happening around the

0:11

world right now and the shutting down of in-person

0:13

events, we have decided to provide free daily

0:16

noon conferences to all radiologists worldwide.

0:19

Today we are joined by Dr. Mahan Mathur.

0:21

He's an associate professor of radiology

0:23

and biomedical imaging at Yale School of

0:25

Medicine, Associate Program Director of

0:27

Diagnostic Radiology Residency, and Director

0:30

of Medical Student Education in Radiology.

0:33

He has been awarded four times the

0:34

Yale Radiology Teacher of the Year.

0:36

A reminder that we'll be using the Q and A feature

0:39

again today for a Q and A session at the end, with

0:41

whatever time we have remaining. Please use this

0:44

Q and A feature to ask all questions, and we'll

0:46

get to as many as we can before our time is up.

0:48

That being said, thank you so

0:50

much for joining us today. Dr. Mathur,

0:51

25 00:00:51,750 --> 00:00:53,310 I will let you take it from here.

0:53

All right, thank you very much.

0:56

I'm, uh, I'll just assume that

0:57

everyone can hear me nicely.

0:59

Um, and we have now 401 participants,

1:03

402, so we are up and going.

1:05

Um, as, uh, as was mentioned, I'm, uh, Mahan Mathur.

1:08

I'm a radiologist at Yale, and today,

1:11

so yeah, we're gonna be talking about

1:12

imaging of the gallbladder and bile ducts.

1:14

I'm gonna start off with some unknown

1:15

cases, uh, to whet your appetite for,

1:18

uh, the content that is to follow.

1:21

So this is the first case, MRI images.

1:25

Coronal T2, another coronal T2,

1:30

an axial T2 fat sat over here.

1:33

You guys wanna write down your

1:35

answers in the chat feature,

1:37

feel free to do so, see what you think.

1:41

I'll let you know if you're right or wrong.

1:44

All right,

1:45

so let me move on to the next case now, and then

1:48

we can see what the answers were to the first one

1:54

over here.

1:54

So we got a bunch of people for the first one,

1:56

uh, giving answers that, uh, would be correct.

1:58

This is case number two.

1:59

What do you guys think

2:00

over here?

2:02

Got a T2-weighted image.

2:04

Now we've got an axial T1.

2:06

This is out-of-phase, and this is the in-phase image.

2:10

All right, so a few answers are coming up over there.

2:14

I'll give you, uh, wait till we got at least about

2:15

10, and then we'll move on to our next case.

2:19

8, 9, 10. All right, let's move on to the next case.

2:23

Let's see what people thought

2:24

of the other case over there.

2:27

All right,

2:28

so a few people were struggling with that one.

2:31

A few people got it right over there.

2:32

So we'll talk a little bit about it afterwards.

2:34

Uh, how about case number three?

2:36

What do you guys think?

2:37

Feel free to type in your answers.

2:38

We have a coronal T2 image,

2:41

and I'm giving you an MRCP as well.

2:46

So I'll show you, I think I have about six unknown

2:47

cases at the beginning, and we'll go through

2:49

all of them through the course of the talk.

2:50

So a lot of the answers are coming out a

2:51

little bit faster over here, 13, 14, 15.

2:55

A few people using the Q and A feature as well.

2:58

All right, so we got some good

2:59

answers over here. A lot of answers.

3:01

Let's move on to our next case.

3:03

A lot of people,

3:07

yeah, some people got that

3:08

answer for case three correctly.

3:09

Very good.

3:10

Case number four, what do you think?

3:11

I'm showing you a CT scan now.

3:12

Axial CT and then fluoroscopic image, upper GI exam.

3:20

I really like this case.

3:21

It's one of my favorite cases, and we'll go

3:23

through it at some point during the talk.

3:25

We

3:26

don't see it that often, so I thought I would

3:29

share it with you, uh, today during this talk.

3:36

All right.

3:36

Let's see.

3:38

A few people have, uh, come up with some answers.

3:40

I'll move on to our next case.

3:44

Let's see what we had over here.

3:46

Yeah, some people had the right answer for that one.

3:48

Case number five, or I think it may be

3:50

one of our last unknown cases, or second

3:52

to last. I'm just showing you one image.

3:54

It's a, um, axial T2-weighted image.

3:57

Uh, couple of interesting findings over here.

4:02

Are you able to come up with a specific

4:03

diagnosis?

4:07

All right.

4:07

I'll wait for

4:08

maybe another 10 on the thing.

4:10

Let's see what people come up with over there.

4:15

All right.

4:16

A lot of people came up.

4:17

I see some good answers over there.

4:19

Case number six, I think this might be the last one.

4:22

CT scan looks like it may be a younger

4:24

patient, if that helps anybody.

4:28

Classic signs shown over here.

4:29

We don't see it that often.

4:31

If you've seen it, you know what it is.

4:33

It looks like a lot of people

4:34

may know what this one is.

4:39

So let's see what we have for our last one.

4:41

Yeah, a lot of people like that.

4:42

One.

4:42

Good, good job.

4:43

I think a lot of people got those answers, uh,

4:45

correct in some, um, of those interesting cases there.

4:48

So listen, we have a lot to cover this, uh, this talk.

4:52

Uh, we've talked about gallbladder, talked about bile

4:53

ducts, talked about a lot of different conditions.

4:56

But you know, in, in the midst of all that, I also

4:59

want you to sort of get out some discrete objectives

5:01

that when you finish this listening to this, you

5:03

can say, this is what I learned from this talk, you

5:05

know, despite all the things that I've shown you.

5:07

And so the objectives are threefold.

5:09

Firstly, to recognize the multimodality

5:11

imaging appearance of acute

5:12

cholecystitis and its complications.

5:15

Uh, we may be used to looking at this on ultrasound.

5:17

Um.

5:18

Maybe we'll look at it on MR. Maybe we'll look

5:20

at it on CT, because we increasingly use these

5:22

modalities and, uh, to identify, uh, problems

5:25

with the gallbladder and the biliary tree, obviously.

5:27

And so, uh, we wanna make sure we

5:29

know what cholecystitis looks like.

5:31

Second objective is, uh, regarding the bile ducts.

5:33

And I want you to be able to compare and

5:34

contrast the imaging features of different

5:36

diseases which result in cholangitis.

5:39

Oftentimes it's difficult to make that specific

5:41

diagnosis, but there are some diseases that manifest

5:44

in certain ways that allow us to make that diagnosis.

5:47

And so we'll talk a little bit about those clues.

5:49

And finally we'll talk about cholangiocarcinoma.

5:52

So by the end of this talk, I'm hoping that you can

5:54

describe the imaging appearance of cholangiocarcinoma

5:57

very confidently to referring providers.

5:59

Um, if, uh, if that is the question

6:01

in, in their, uh, clinical indication.

6:04

And so how are we gonna go about doing this?

6:06

Well, we'll split the talk into two halves.

6:08

The first half is gonna be gallbladder,

6:10

the second half is gonna be the bile ducts.

6:12

And in each of them, we're gonna follow

6:14

a very, very simplistic sort of course.

6:17

We're gonna talk about the anatomy, we're

6:19

gonna talk about non-neoplastic conditions, uh,

6:21

such as inflammatory conditions for both.

6:23

And then we'll talk about masses.

6:25

The masses could be benign,

6:26

the masses could be malignant.

6:28

So we'll do that with the gallbladder and

6:29

we'll follow that up with the bile ducts.

6:34

Let's talk about gallbladder anatomy.

6:36

All right?

6:36

So I wanna make sure we're all on the same page before

6:38

we move on to some of those interesting cases, right?

6:41

It lives in the right upper quadrant,

6:42

it's oval-shaped, sometimes pear-shaped.

6:44

It's fluid-filled.

6:45

So in general it'll be anechoic on ultrasound. You can

6:48

see an ultrasound image over here on grayscale

6:50

imaging, anechoic gallbladder, and it has different

6:53

regions — the fundus of the gallbladder, the body of

6:55

the gallbladder, the neck of the gallbladder, um,

6:58

and you wanna make sure that anytime you sort of

6:59

look at the gallbladder, particularly on ultrasound,

7:02

that you do actually try to see the neck, right?

7:04

Because oftentimes you can have a stone

7:05

that's stuck right in the neck, and that,

7:07

you don't evaluate that

7:08

properly, uh, you would miss it.

7:11

Um, size-wise, you know, I don't really

7:12

like to remember numbers, uh, too much, but

7:15

I think, you know, four by ten, five by ten.

7:18

But transverse sagittal dimension — if you have a ballpark

7:20

number of what the, how big the gallbladder's supposed

7:22

to be, it can allow you to, uh, make the diagnosis

7:25

of, say, gallbladder distension more confidently.

7:27

Right?

7:28

A lot of us do it subjectively, but

7:30

sometimes you want to be very confident

7:31

and have an objective measurement.

7:33

And between the two, I would say, you know, the

7:34

four centimeters transverse dimension is oftentimes,

7:37

uh, more specific for gallbladder dis—, uh, for

7:39

distension, in that you can have gallbladders that

7:42

are generally long, but they shouldn't be wide.

7:44

Um, and so that's what I sort of look for

7:47

when I look at the gallbladder, and the

7:48

wall thickness — up to three millimeters.

7:50

Three millimeters or less is where we like it to be.

7:55

On MR, we can oftentimes see the

7:57

gallbladder, uh, as nicely as this, right?

8:00

You can see the fundus there, the

8:01

body, you can see the cystic duct,

8:03

the neck of the gallbladder over here.

8:05

And, uh, we could see it on the axial T2 and T1

8:07

weighted images. In general, because it contains fluid,

8:10

it'll be T2 hyperintense and T1 hyperintense.

8:14

But of course, there is variable signal within

8:16

it, depending on whether the patient is fasting

8:18

and the presence or absence of biliary sludge.

8:21

And when you have stuff like that, often

8:23

have more layering T2 hypointense signal.

8:26

And sometimes that can also be

8:27

T1 hyperintense, all right?

8:29

So it's not always gonna have that simple

8:30

appearance, but by and large, when you see

8:33

this sort of appearance, nothing really to

8:34

worry about in terms of the gallbladder.

8:38

Gallstones — what do they look like?

8:39

Well, gallstones on ultrasound will be echogenic.

8:42

They'll have clean shadowing.

8:44

All right.

8:44

And the shadowing is really dependent on

8:45

the size, and generally stones that are

8:47

greater than three millimeters will shadow.

8:48

It's not so much the composition.

8:50

Gallbladder stones itself can be

8:51

made up of cholesterol, pigment.

8:54

Uh, but most commonly it's a mixture of both.

8:56

And when you look at them in the

8:57

gallbladder, they'll be mobile.

8:58

You turn the patient around, they'll move all

8:59

over the place. And they are common, right?

9:01

So we're gonna see this in at

9:02

least 20% of our population.

9:04

Um, and so it's important to know what

9:05

that looks like, uh, on ultrasound.

9:09

On MR, pretty much all stones

9:11

will be T2 hypointense.

9:13

You can see them stuffed in the gallbladder over here.

9:16

Over here, you can also see a T2 hypo-

9:17

intense stone within the, uh, common bile duct.

9:20

And to some degree you may see some,

9:22

uh, T1 hyperintensity within stones,

9:26

especially if they contain pigment.

9:28

These pigmented stones may be sometimes T1

9:30

hyperintense, but whether or not it has pigment

9:33

or not, it'll always be T2 hypointense.

9:36

And so those are the sequences I'm gonna look

9:37

at when I'm looking for, uh, gallstones on MRI.

9:44

Now what about gallbladder sludge?

9:45

We talked a little bit about that in MR imaging.

9:47

On ultrasound, low-level echoes will layer.

9:50

There'll be no shadowing for the most part.

9:52

If you move the patient around,

9:53

gallbladder sludge should move along with it.

9:55

And then occasionally you run into tumefactive

9:57

sludge, or tumor-like sludge.

10:00

It looks more mass-like, tends to not really move.

10:03

And, uh, it can become problematic because

10:05

how do you differentiate that from a tumor?

10:07

Well, it should have no flow, uh, unlike

10:10

tumors or even polyps, which do have some degree

10:12

of flow. But sometimes, you know, on ultrasound,

10:14

it's very difficult to detect subtle areas of flow.

10:17

So if you think something looks like

10:18

tumefactive sludge, you could do one

10:20

of two things — get a follow-up ultrasound

10:21

in a few weeks to see if it changes,

10:23

in which case it probably is

10:24

just sludge and not a tumor,

10:25

or I would even sometimes suggest

10:27

getting an MRI, where MRI is very good

10:29

to look for subtle areas of enhancement.

10:34

That's it for anatomy, right?

10:36

We talked about the size. We talked

10:37

about what gallstones look like.

10:38

We talked about what sludge looks like, and

10:40

that's all within the realm of normal anatomy.

10:42

So let's go through some interesting, uh, non-

10:44

neoplastic conditions of the gallbladder now.

10:47

And this is case number one.

10:48

I think a lot of you, uh, got

10:49

case number one correctly.

10:51

Uh, this is a coronal T2-weighted image.

10:54

This is a different slice in the same patient.

10:55

I'm showing you now an axial T2 fat sat image.

10:59

And what do we see?

10:59

We see a gallbladder that looks distended, right?

11:01

You can measure in its long axis.

11:03

You can measure it in its short axis.

11:05

Um, certainly looks very distended.

11:07

Probably contains some sludge over here, but also

11:09

contains a stone — T2 hypointense stone — that's

11:12

impacted in the, uh, gallbladder neck.

11:14

This stone results in this gallbladder

11:16

distension. Look at the gallbladder wall.

11:18

It's very, very thick, particularly on the T2

11:20

fat-saturated images — way more than three millimeters.

11:23

There's all this inflammatory change around

11:25

it on the T2 fat-saturated images.

11:27

This is classic for acute cholecystitis.

11:32

Right.

11:32

So acute cholecystitis essentially occurs

11:34

because there's an outlet obstruction, and

11:36

by and large, it's almost always going to

11:39

be due to the presence of a stone, right?

11:41

Calculous cholecystitis, which it was in this case.

11:43

And in a small subset of patients,

11:45

you may get acalculous cholecystitis.

11:48

These are patients who are gonna be hospitalized

11:49

for a long period of time, uh, very sick.

11:52

We often see patients who have

11:53

trauma or extensive burns.

11:56

Um, they can get, um, sludge that's very tenacious and

11:58

sort of just sticks in there in the gallbladder neck,

12:01

causing gallbladder distension and cholecystitis.

12:05

On ultrasound, you're gonna look for stones,

12:06

'cause stones are by far the most

12:08

common cause of cholecystitis.

12:10

You can look for the distension that it causes.

12:11

You can look for the gallbladder wall thickening.

12:13

You're gonna look for the fluid, but obviously you

12:15

can look for that positive sonographic Murphy sign.

12:17

So for that, you're gonna place the probe

12:19

right over the gallbladder, push down in

12:21

a — that's the area of maximal tenderness.

12:24

You can call that a positive sonographic Murphy sign

12:26

if the patient is hurting all over their body, um,

12:30

equally — and even equally over the gallbladder.

12:32

It's hard to call that a positive sonographic

12:34

Murphy sign. The Murphy sign has to be more tender

12:37

right over the gallbladder when you press on it.

12:42

Here's another case showing a CT scan over here.

12:47

In this one, the gallbladder

12:48

doesn't look happy, right?

12:49

Probably not as distended as it was in the prior exam.

12:52

But as you look at it, lots of inflammatory

12:54

change surrounding this gallbladder.

12:56

You see a fleck of what's probably

12:58

a calcified gallstone over here.

13:00

But if you look at the wall over here,

13:01

particularly the mucosa — quite hyperemic, quite

13:03

hyperemic, quite hyperemic. What happens here?

13:06

You lose it, and you see hyperemic again.

13:09

So this is concerning for

13:13

gangrenous cholecystitis.

13:16

Now, the incidence, uh, has

13:17

been reported to be up to 38%.

13:19

That feels a little bit high to me.

13:20

We don't see it that often, but

13:22

unfortunately the mortality is quite high.

13:24

So patients have gangrenous cholecystitis, and

13:27

mortality rates of up to 20% have been reported.

13:30

And the pathophysiology here is that you have

13:32

cholecystitis, but that pressure, um, compresses the

13:36

wall and leads to ischemia and potentially necrosis.

13:39

Now, one of the key, uh, clinical findings,

13:42

uh, that's important to know is that the

13:43

sonographic Murphy sign may be negative.

13:45

It's been reported to be negative in up to two

13:47

thirds of patients with gangrenous cholecystitis.

13:49

So you have to have, um, good, uh, imaging,

13:54

and, uh, you know, really look for that wall.

13:56

Um.

13:57

Missing layers of that wall, uh, to be able

14:00

to call it gangrenous cholecystitis, 'cause

14:01

it could be difficult to call clinically. Uh,

14:04

on imaging, you're looking for those mucosal

14:06

ulcerations or discontinuity — the classic

14:09

ultrasound findings of sloughed mucosal membranes.

14:11

This is one exam.

14:12

We can see some sloughed mucosal membranes,

14:14

but to be honest, don't see it that often.

14:16

Uh, more oftentimes I'll see it on CT

14:18

scan, where a portion of the gallbladder

14:20

mucosa is just not enhancing — it's missing.

14:23

Um, and that is, uh, highly concerning

14:25

for gangrenous cholecystitis.

14:31

Here we have another case.

14:32

I'm showing an axial T2

14:34

weighted image of the abdomen.

14:37

Again, the gallbladder doesn't look too happy.

14:38

Here, we can see some layering sludge.

14:41

We follow the gallbladder wall here — it's missing.

14:43

But unlike the other case, there is not only

14:46

do we have discontinuity, but a portion of

14:48

the gallbladder is now extruded out through

14:49

this area of discontinuity and is abutting

14:52

the liver and maybe invading the liver itself.

14:54

Some mild inflammatory changes associated with this.

14:57

This finding is concerning

14:59

for perforated cholecystitis.

15:01

So as you can imagine, these

15:03

things are all on a continuum.

15:04

You have cholecystitis, you can get ischemia causing

15:07

gangrenous cholecystitis. To that area of ischemia,

15:09

you can get perforation.

15:11

Uh, mortality rates here are

15:12

also quite high — up to 16%.

15:14

This tends to happen in older patients.

15:17

Most commonly it perforates right at the fundus,

15:19

not in this case, but most commonly at the fundus.

15:21

And that's thought because the, uh,

15:23

blood supply there is most distal.

15:25

So that's the area that

15:27

is compromised first.

15:28

Um, and it's classified by acute, subacute,

15:32

or chronic perforated cholecystitis.

15:34

And by and large, we end up seeing

15:36

subacute cholecystitis most common, where

15:37

you see a pericholecystic abscess.

15:39

As you can see in this case. In cases of

15:41

chronic cholecystitis, you can have fistulas

15:44

to the CBD or the duodenum that result, you

15:46

know, from chronic ongoing inflammation.

15:49

And so the imaging features that you're

15:50

looking for here is that discontinuity that

15:52

you get with gangrenous cholecystitis, but

15:53

now it's associated with a fluid collection.

15:56

One sign that's been described in ultrasound

15:58

quite aptly is called a hole sign, where you

16:01

literally have a defect in the gallbladder.

16:02

So this I think is another case where

16:04

you have lots of gallstones here with

16:06

shadowing, focal defect in the gallbladder,

16:09

and content that's extruding outwards,

16:11

resulting in the focal abscess there.

16:18

How about this case over here?

16:20

I always like looking at the scout images

16:22

of CT scans, 'cause, uh, sort of helps me

16:25

uh, with my plain film skills in some sense.

16:28

This is a scout from a CT scan.

16:29

It's sort of honed in over, uh, the abnormality.

16:32

I sometimes show my trainees this and they

16:34

call it, um, uh, uh, pneumatosis, which

16:38

wouldn't be a bad, uh, you know, differential,

16:41

except this talk is on the gallbladder.

16:43

And so we have a few people here

16:45

chiming in, so I'm happy to see it.

16:47

Yeah.

16:47

And we got some emphysematous cholecystitis.

16:50

I like that for, uh, this case.

16:53

And so this is emphysematous cholecystitis, right?

16:56

This is something that, um, is

16:57

seen often in diabetic patients.

16:59

Again, a high mortality rate.

17:01

So acute cholecystitis by itself is

17:03

okay, but once you start to get those

17:05

complications, the mortality rates start to go

17:08

increasingly higher — up to about 20% with this.

17:11

And in this case, you have an

17:12

infection with gas-forming bacteria.

17:15

And on ultrasound, you see non-dependent

17:18

hyperechoic areas with dirty shadowing.

17:21

You can see over here — hyperechoic area on the wall.

17:24

The shadowing is not very clean and dark like you'd

17:26

see with a gallstone, but rather, uh, sort of, uh,

17:29

low levels of gray that's sort of going downwards.

17:32

And you can see this on a CAT scan as well.

17:34

Some non-dependent areas of, uh, of gas

17:37

accumulation within the wall over here.

17:40

And, you know, sometimes, uh, you know, you, you see

17:42

not uncommonly intraluminal gas in the gallbladder.

17:45

Like over here — this looks like there's an air

17:48

fluid level, and that itself is not so concerning.

17:50

You can see that post-ERCP potentially, you can

17:53

see that if a stent has been placed in the biliary

17:56

tree, potentially there's a fistula to the bowel.

17:58

But when I really get concerned for emphysematous

18:00

cholecystitis is when it's hugging the wall,

18:02

and particularly when you see it along the

18:04

non-dependent portion, such as, uh, in this

18:07

case over here. As I said, high mortality rates.

18:13

And this was case number two.

18:14

A few, uh, of, uh, the folks out

18:16

there got this one correctly.

18:18

If you, uh, want a second shot at

18:21

it, feel free to type in your answers.

18:23

Um, axial T2-weighted image.

18:25

Actually, this is, uh, more of an oblique

18:27

image to be honest with you, and you can see

18:28

that there's gallbladder sludge over here.

18:31

But what I wanted to show over here are

18:32

the collection of dark signal that's

18:35

along the surface of the gallbladder.

18:37

Over here.

18:37

If you look very carefully, you can see the

18:39

wall here and it's very, very hard to follow.

18:42

And in that area, there's that gap.

18:44

It looks like there's these, uh, dark T2 signal.

18:47

If you look at T1 in and out of

18:48

phase, what happens to that dark signal?

18:50

It's certainly dark on both, but from the out of

18:53

phase to the in-phase, there is blooming artifact.

18:55

It gets much darker.

18:57

What other thing is doing that, uh, similarly

18:59

on this image? Look at the bowel. Transverse

19:01

colon gets much darker on the in-phase image.

19:04

That's gas within the gallbladder wall.

19:07

And this indeed is a case of emphysematous cholecystitis.

19:11

We're gonna talk about what pneumatosis

19:13

looks like in a little bit, but this

19:14

is a case of emphysematous cholecystitis on MRI.

19:18

Um, you know, I show this case because, uh, you know,

19:20

hopefully if you were able to sort of follow the

19:23

imaging algorithm correctly, you should never get to

19:25

the point where you're doing an MRI to diagnose this.

19:27

This is something that, um, you really should

19:31

be diagnosing on ultrasound. But in this case,

19:34

uh, we had the suspicion of it on ultrasound.

19:37

They wanted to get an MRI. I said, sure.

19:39

Let's, let's get it. Let's get it quickly.

19:40

And I wanted to add an in and out phase to show

19:42

that blooming, just to show you what that would

19:44

look like if you encountered it on MR imaging.

19:49

How about this case?

19:50

Move on to something slightly different.

19:53

Classic sign in ultrasound imaging.

19:55

Feel free to type in your answers if you

19:57

want a shot at, uh, some glory over here.

20:00

All right.

20:00

We got a lot of answers here.

20:02

Let's have a — yeah.

20:03

West, West, West.

20:05

Very, very good.

20:05

Everyone's chiming in here.

20:07

All are correct.

20:08

Wall-echo-shadow complex.

20:10

All right, so the reason I wanted to show this is,

20:13

um, at least when I was a trainee, and, and,

20:16

and I'll admit even now, sometimes, you know, uh, I

20:18

get confused between different things that can cause

20:22

uh, that — that are included, I would say, in the

20:24

potential differential for the wall-echo-shadow complex.

20:27

So kinda laying them side by side, I think

20:29

helps me a lot to sort of understand what

20:31

each of them look like, and understand that

20:33

they actually do look quite different, right?

20:35

So the wall-echo-shadow complex is you literally see

20:38

the wall, which is echogenic, um, the echo, which is

20:41

the gallstone, and a shadow behind it. And that tells

20:43

you it's a gallbladder that's filled with stones.

20:46

Okay.

20:47

Porcelain gallbladder, on the other hand, is — we

20:49

have calcifications of the gallbladder wall.

20:52

All right, so there's no wall,

20:54

there's no echo, there's no shadow.

20:55

You literally have bright echogenic

20:57

content that's shadowing — that is along

21:00

the surface of the gallbladder wall.

21:02

We'll talk a little bit about porcelain gallbladder wall

21:04

later, but the important thing to know here is that

21:06

there is some association with cholangiocarcinoma.

21:10

Finally, something that we've touched

21:11

upon already is emphysematous cholecystitis.

21:13

Which can also give you echogenic

21:15

foci on the gallbladder wall.

21:17

Uh, and that's — that's indicative of air in the

21:19

gallbladder wall, except the shadowing is not

21:21

nice and clean. Over here,

21:23

it's quite dirty shadowing.

21:24

And you'll also see that in this

21:26

instance on the non-dependent wall.

21:28

And so that's what emphysematous cholecystitis looks like.

21:30

And of course it's important to differentiate

21:32

these, 'cause this is an emergency,

21:34

while these two are not as emergent.

21:36

And what I would say is that you should

21:38

always try your best to differentiate them,

21:39

and for the most part you'll be able to.

21:42

But if you're ever in doubt, you know it's

21:44

okay to get cross-sectional imaging if

21:46

you need to in order to differentiate it.

21:47

And the reason I say that is because you

21:49

don't wanna be missing an emphysematous cholecystitis.

21:52

Um, and it's okay to sort of get it if you're

21:54

in doubt after you've gone through sort of an

21:56

algorithmic approach to evaluating them.

22:00

Good.

22:00

So that's wall-echo-shadow complex.

22:02

This is case number three.

22:04

Move on to something slightly different if

22:06

anyone wants to chime in, uh, who wasn't

22:07

able to chime in before for their answers.

22:08

A lot of people got this one right.

22:10

Uh, this is one of, uh, again,

22:12

a, a favorite case of mine.

22:14

And so we have a few people over here.

22:16

Lemme see.

22:18

What we think. Yeah, a lot of

22:19

people calling it Mirizzi’s syndrome.

22:22

Mirizzi.

22:22

Mirizzi.

22:23

Okay, so I like it for Mirizzi syndrome.

22:25

So what are we seeing over here?

22:27

We have a T2 weighted image

22:28

and a coronal 3D, uh, MRCP image.

22:30

We're seeing a gallbladder that's distended,

22:32

the cystic duct that's also quite distended.

22:34

But look what we see at the interface of

22:35

the cystic duct and the common hepatic duct.

22:38

We see a T2 hypointense gallstone.

22:41

Now the common hepatic duct that is

22:44

cephalad to this is dilated over here, and

22:48

distal over here looks like it's normal.

22:50

And this is sort of what I was trying to show

22:51

on the, uh, MRCP image — that above this

22:54

filling defect, all the ducts are dilated, and

22:56

below it, it's within normal limits, right?

22:59

So this is a case of Mirizzi syndrome, where you have

23:02

common hepatic and intrahepatic ductal dilatation,

23:05

not due to a stone in the, you know, biliary tree

23:08

per se, but rather to a stone in the gallbladder neck

23:11

or cystic duct that's causing extrinsic compression.

23:14

And so you'll see this, uh, from time to time.

23:17

It's not that uncommon, but it's important to

23:19

be able to confidently diagnose it when you see it.

23:21

So the key is the stone right over there,

23:23

upstream from it dilated, downstream looks okay.

23:29

And this case — this is one of my favorite

23:31

cases the last two years that we've had. I

23:33

haven't — I've only seen one case of this.

23:36

Uh, feel free to chime in with the answer

23:38

uh, if you hadn't had a chance

23:39

uh, in the first, uh, go-around.

23:44

So here I'm showing you a CAT scan, and

23:46

why would I be showing you a GI study?

23:48

That's sort of not something we would do typically

23:51

for gallbladder and, uh, and, uh, biliary conditions.

23:54

So let's give, uh —

23:57

A lot of people calling it what I think

23:59

it is — Bouveret syndrome, stone to duodenum.

24:01

Very good.

24:01

Yeah, exactly it.

24:02

So this is a patient who, um, I think had come

24:05

in with abdominal pain, abdominal distension.

24:07

On the CAT scan you can see that there's essentially

24:09

a gastric outlet obstruction, and I don't know

24:11

if this was picked up initially on the CAT scan.

24:13

In retrospect, it's always much easier, but

24:15

there looks like there's actually a, a pretty

24:17

hypodense filling defect right in that first

24:19

portion — maybe second portion — of the duodenum.

24:22

Um, and they got an MRI, which I'll show you

24:24

subsequently, but they also wanted to get an

24:26

upper GI series, which was definitely overkill.

24:29

But, uh, we can see that beautiful

24:31

filling defect over here, um, and really

24:33

just looks like a very large gallstone.

24:36

And this turned out to be a case of Bouveret syndrome.

24:39

All right.

24:39

And I'm probably — I'm butchering

24:41

that pronunciation, so to anybody who

24:43

pronounces that better, I apologize.

24:45

Um, and so that is sort of, uh, along — not

24:48

really the lines of Mirizzi, but you know,

24:49

um, where you have sort of a chronic

24:53

uh, perforated cholecystitis in some sense.

24:56

But what ends up happening is that the stone gets out

24:59

of the gallbladder and now lives in either the stomach

25:02

or the duodenum, and that causes an obstruction.

25:05

And so it's essentially a biliary enteric fistula.

25:08

It's usually due to a case of chronic cholecystitis,

25:10

though other causes that can also potentially do

25:12

that have been described in the literature.

25:14

Uh, but you can see on the MR how dark this looks.

25:17

This looks exactly like a, a

25:19

gallstone, albeit a larger gallstone.

25:21

And in fact, this is a patient who'd been, um, having

25:24

these fistulas for a while. Um, on an earlier scan had

25:28

come in, um, had a gastric outlet obstruction, uh, at

25:30

that point as well, but also had a gallstone ileus.

25:33

You can see a stone that's

25:35

lodged here in the small bowel.

25:37

And so this is a person who had been throwing

25:38

stones for a while, um, resulting in, uh, small

25:42

bowel obstructions and gastric outlet obstructions.

25:46

So, good on, uh, everyone who

25:47

got that, uh, question correct.

25:50

All right, I'll show you another unknown case over here.

25:52

This is one of my favorite diagnoses, and we see it,

25:55

uh, not on — well, this we don't see commonly, but,

25:58

uh, you'll see what I'm getting at in a little bit.

26:00

So this is a CAT scan, intravenous contrast, and, uh —

26:05

I'm showing you something over here and I'll ask

26:08

the community to go out and, and give their answers

26:10

and try to be as specific as possible for what

26:13

you think is going on and what's causing this.

26:14

I think based on these images, we can have

26:17

a specific answer, and I'll show you a few

26:19

more images after to help you out.

26:22

So we have a few people, uh,

26:27

going out there and trying

26:28

to come up with an answer.

26:29

Let me see if, uh, we're on the right track over here.

26:32

So, you know, hydatid cyst is not a bad thought.

26:35

Uh, amebic cyst.

26:36

Uh, so we're going on the infection

26:38

route, which is correct. Bowel.

26:41

So all things that are sort of along the right lines.

26:43

But let me show you something over here.

26:45

Actually, we had one more thing.

26:46

Let me see if somebody nailed it.

26:48

Slipped stone.

26:48

Okay.

26:49

I think that's a, uh, a typo, but

26:51

I like where that person's heading.

26:52

I like what they're thinking about.

26:54

And so let me show you a CAT scan of

26:56

the same patient from, uh, well, I think

26:58

this was about three or four years ago.

27:00

All right.

27:01

A non-contrast CT.

27:02

We don't see that big collection

27:04

there, but what do we see over there?

27:06

Cluster of hyperdense foci,

27:09

dropped stones, and I think people are getting

27:11

a hold of what they think this is now.

27:13

So this is dropped gallstones with an abscess.

27:15

All right, so we can see cholecystectomy clips here.

27:18

And everyone, uh, you know, sort of correctly

27:21

interpreted this as an infectious collection.

27:23

The key here is what's inside of this.

27:25

On the dependent surface, you see a

27:27

little tiny linear hyperdense foci, and

27:31

if you see gallbladder that’s out,

27:32

hyperdense foci in Morrison’s

27:34

pouch with a large abscess,

27:36

gotta think about, uh, abscess

27:38

related to dropped gallstones.

27:39

You can see lots of gallstones

27:40

here, uh, in this patient,

27:42

uh, post cholecystectomy.

27:45

This is what it would look like on an MRI.

27:47

We have a bunch of images here, T1

27:49

weighted and, uh, T2 weighted.

27:51

You can see the gallstones are

27:52

hypointense in this instance.

27:54

Um, you see this is a collection

27:56

that's surrounding it.

27:57

This collection has a thick rim of

27:58

enhancement, and you can see that on, um,

28:02

the DWI and ADC images, that there's an

28:05

abscess over here with restricted diffusion.

28:09

And so the incidence of dropped

28:10

gallstone is actually quite high.

28:11

We see it, uh, you know, quite often

28:13

once you're sort of attuned to knowing

28:15

what they look like — up to about 30%.

28:17

But it's important to remember that only about 0.3%

28:20

of the patients are actually symptomatic from this.

28:22

People can have this and live with

28:24

this, and it's perfectly okay.

28:26

Why does this happen?

28:26

Well, for some reason, the gallbladder perforates,

28:29

or stones sort of slip out during the actual surgery.

28:32

And one of the biggest risk factors is that it

28:34

often happens with laparoscopic cholecystectomy.

28:38

Um, you know, it's difficult to sort

28:40

of remove the gallbladder through small port sites.

28:42

In that instance, there may be some spillage

28:44

of stones. And of course, you know, the more

28:46

stones you have, the sicker the gallbladder is.

28:49

Um, the surgeon’s experience —

28:50

all these play into it, but it's commonly seen in

28:53

Morrison’s pouch, also known as the hepatorenal recess.

28:55

If you see a cluster of hyperdense foci there, the

28:58

gallbladder that’s missing, you gotta think about

29:00

dropped gallstones. And in a certain percentage of

29:03

patients, they'll become symptomatic with an abscess.

29:07

The other thing I'll point out is that while

29:09

the Morrison’s pouch is a very common location,

29:11

it can occur in many different locations.

29:14

And so this is a patient who had a cholecystectomy

29:17

and certainly has dropped gallstones in the

29:19

gallbladder post-cholecystectomy bed itself,

29:22

but also has one in what would be probably the

29:24

left subdiaphragmatic space right over here with a

29:26

uh, you know, a rim of soft tissue surrounding it.

29:28

So this is probably an infection brewing over here.

29:32

And this was a very interesting case of a

29:33

person who actually had a porcelain gallbladder,

29:35

in addition to having a large gallstone,

29:37

had a laparoscopic cholecystectomy,

29:39

there was spillage of stones.

29:40

You can see that large gallstone

29:42

now resides in the pelvis.

29:43

You can see smaller gallstones are also outlining

29:46

the peritoneal spaces of the pelvis over here.

29:48

And some other smaller gallstones are sort of studded

29:51

inside what is probably one of the laparoscopic

29:53

port sites within the anterior abdominal wall.

29:55

So I might see calcifications in the abdomen.

29:59

Um, and the patient is post cholecystectomy.

30:01

I just think to myself, hey,

30:02

could this be a dropped gallstone?

30:04

And, uh, and sometimes

30:06

you can make that dx, sometimes you're just not sure

30:13

about.

30:14

We move on

30:15

to our next topic, and this is when

30:16

it gets difficult, is that as you know,

30:18

not all gallstones are calcified.

30:20

It becomes easier, but a percentage tend to be non.

30:23

So you have a case over here, somebody

30:25

with LFTs and some right pain.

30:28

This is a non-contrast CT.

30:30

This is an actual, uh, tissue mass. That's the liver

30:35

capsule over here in a patient who is post cholecystectomy.

30:38

Um, not a lot of— maybe a tiny fleck

30:42

of calcium here if you look subtly,

30:43

but really looks like soft tissue.

30:45

If you look at the, uh, MRIs done subsequently,

30:47

you can see that there's a little inflammatory

30:52

rim around the liver and multiple small stones

30:54

that are non-calcified, uh, in this patient

30:57

who had dropped gallstones post cholecystectomy.

31:02

All right, so those were a lot of different topics

31:04

that we covered for our non-neoplastic conditions.

31:06

Cholecystitis and all its variants.

31:08

Uh, talked about the wall echo shadow complex.

31:10

Contrasted that with some of the

31:11

things that could potentially mimic it.

31:13

Some of my favorite diagnoses of Mirizzi syndrome,

31:15

Bouveret syndrome, and dropped gallstones as well.

31:18

And so we'll move on to masses — gallbladder masses.

31:22

Another unknown case, uh, for the community out here.

31:25

This is an axial T2, coronal T2.

31:29

What do we think it is?

31:29

Feel free to chime in.

31:30

Type in your answers. Bunch.

31:32

Patient has gallstones.

31:33

We'll ignore that.

31:35

You can see, uh, over here.

31:36

What's this mass at the fundus?

31:42

Let's see if we're all on the right page.

31:43

Yep.

31:43

Adenomyomatosis.

31:44

Very good.

31:46

And so, uh, this is a case of adenomyomatosis, right?

31:49

This is very common.

31:51

We see it almost all the time, but it's

31:53

important to recognize this, um, confidently

31:55

when you can because it is a benign diagnosis.

31:58

And if you're not really attuned

31:59

to it, you may think it's a cancer.

32:01

So what is adenomyomatosis?

32:03

This is taken from Radiopaedia.

32:04

Uh, this is a nice little schematic of what

32:06

it looks like, um, uh, within the gallbladder.

32:10

Adenomyomatosis is a condition where, for

32:12

whatever reason, you have hyperplasia of

32:15

the epithelial wall of the gallbladder.

32:17

So the gallbladder epithelium gets thickened,

32:19

and as a result, you get these mucosal

32:21

invaginations into the smooth muscle of

32:24

the gallbladder, forming these diverticula.

32:27

Right? And

32:28

we call these diverticula or Rokitansky-Aschoff sinuses.

32:31

And so these diverticula then end up

32:34

being areas of relative biliary stasis.

32:37

And then you can have bile or cholesterol

32:39

crystals that deposit within these

32:41

spaces, resulting in adenomyomatosis.

32:44

It can be focal, it can be

32:46

segmental, it can be diffuse.

32:50

And so this is a case where it's more diffuse.

32:52

On ultrasound, you can see these echogenic

32:54

foci with a ring-down artifact that's

32:57

showing you sort of the cholesterol that's

32:58

accumulating within these diverticula.

33:00

That's typically associated with

33:01

areas of gallbladder wall thickening.

33:04

You can see on the CT scan, it can be quite,

33:07

um, uh, you know, worrisome when you look at it.

33:11

We see pronounced gallbladder wall thickening on

33:13

the MR. Um, you can see if there are focal cystic

33:15

spaces inside the gallbladder wall and they are

33:18

non-enhancing when you give post-contrast sequences.

33:21

Um.

33:22

And one of the more common manifestations is what

33:24

I've shown you in this case where you have the cystic

33:27

spaces, particularly at the gallbladder fundus,

33:30

and they call it the string of beads sign. The

33:32

ultrasound equivalent is here, where you see

33:35

focal area thickening with echogenic foci, and at

33:38

least one of them has ring-down artifact over here.

33:40

So when you see something like this,

33:42

um, you gotta think of adenomyomatosis.

33:45

And if a case like this, you know, you're not

33:47

entirely sure about the ring-down artifact,

33:49

or if this could be potentially a tumor or

33:50

something, or a big polyp, then I think getting

33:52

an MR is very, very reasonable in that instance.

33:58

How about this case over here?

34:00

So we have a T2 fat-sat image and

34:03

a T1 post-contrast image with subtraction.

34:06

We see a few little things in the gallbladder.

34:08

What do we think these are?

34:12

So we got people chiming in with some answers.

34:16

All right.

34:17

Let's see if everyone's sort

34:18

of on the right page over here.

34:20

Yeah.

34:20

Polyps, polyps, polyps.

34:21

So everyone seems to know what this is.

34:23

That's great, right?

34:24

This is what polyps look like.

34:26

All right.

34:26

This is what we can see on the ultrasound as well.

34:28

This may be, I think, a different patient,

34:29

multiple masses, one of which has a little

34:32

bit of flow in it, uh, on color Doppler imaging.

34:35

And so there are different types of polyps. By, uh,

34:37

far the most common is these cholesterol polyps.

34:39

You can also have inflammatory

34:40

polyps in about 10% of cases.

34:42

The ones of course we worry about are adenomatous polyps.

34:45

Luckily, they're the least common.

34:47

But we need to make sure that, um, we have some way

34:51

of sort of assessing whether this could be an adenomatous

34:53

polyp or not, because these are premalignant.

34:57

So when we talk about cholesterol polyps,

34:59

it's the most common type of, uh, polyp.

35:01

Um, they look polypoid in their appearance.

35:04

They're often described in ultrasound

35:05

as a ball-on-a-wall appearance.

35:07

Unlike stones, they are non-mobile. They also

35:10

don't shadow. And you may see flow, but

35:13

these things tend to be quite small, so

35:14

detecting flow in them can be challenging.

35:17

And cholesterol polyps are often very small.

35:20

They’ll be multiple,

35:21

less than five millimeters in size.

35:23

And that number of five millimeters

35:25

is an important one to remember.

35:27

And, um, you know, there's a lot of sort of debate

35:30

how one follows these polyps, but I think these

35:32

sort of guidelines are simple and practical.

35:35

And that if you see lesions like this in the gallbladder

35:38

that are less than five millimeters, you can ignore it.

35:40

Particularly if they're multiple. If it's greater

35:43

than 10 millimeters, at the very least, you should

35:45

refer them to somebody who resects gallbladders.

35:48

Because at this rate, there's a higher

35:50

chance of it being an adenomatous

35:52

polyp with potential for malignancy.

35:55

So they may decide to still follow it,

35:56

but they may decide if the patient

35:58

is a surgical candidate, they take it out.

36:00

And five to 10 millimeters

36:02

generally requires some follow-up.

36:04

Everyone sort of does this a little

36:05

bit differently, but in general, the first

36:07

follow-up can be in about six months,

36:08

then another six months, then a year.

36:11

You can sort of do that for a couple of years and at

36:13

some point, you know, there are no good guidelines

36:15

to sort of suggest when you absolutely stop.

36:17

But generally, if things have not grown for about

36:20

four or five years, you can be reassured that

36:22

it's almost certainly going to be something benign.

36:29

Another case over here, right?

36:30

So we have an axial T2-weighted image, and I'm giving

36:34

you a T1 post-contrast image over here and I'll

36:39

tell you that, uh, you know, this is the finding

36:42

over here, and what do people think this is gonna be?

36:48

So we do see some stuff here that's

36:50

layering sludge—I'll ask to ignore—

36:52

but what do we think this is gonna be?

36:53

So I see a bunch of people

36:54

coming up with some answers here.

36:57

Carcinoma, sludge ball.

36:58

Yeah, I like the sort of

37:00

answers that are coming out here.

37:02

So this was a tough one.

37:03

I remember I read this. A few

37:05

people got the correct answer.

37:06

I read this a couple of years ago. I was just

37:09

starting out and on call, and, um, it was an ultrasound, and

37:12

they saw this thing and they thought, you know,

37:14

could this be a tumor or tumor-affected sludge?

37:16

They weren't sure.

37:17

And I think that's sort of the top two

37:18

answers that are coming out from the group.

37:20

And, uh, they got an MR, which I think is completely

37:22

appropriate, and I looked at it, and certainly as T2,

37:26

um,

37:27

uh, sort of intermediate signal, but

37:28

sludge can certainly look like this.

37:30

Looks a little bit mass-like, but that's

37:32

what tumor-effective sludge can look like.

37:34

The key is the post-contrast sequence, and

37:37

the reality is that sludge should not enhance.

37:40

So this has enhancement.

37:42

It's low-level enhancement, but it's

37:43

definitely enhancing. As a comparison,

37:45

look at the bile over here.

37:46

That's not enhancing. That's quite dark.

37:48

This has low-level enhancement.

37:50

So once you sort of, uh, are appreciative

37:52

of that level of enhancement,

37:53

you gotta be worried about a tumor over here.

37:56

And this turned out to be a gallbladder

37:57

neoplasm. An unusual gallbladder neoplasm

37:59

is actually a squamous cell cancer of the

38:01

gallbladder, which is very, very uncommon.

38:03

By far, the most common is an adenocarcinoma.

38:06

But this was a primary gallbladder neoplasm

38:08

nonetheless. Uh, happens in the older population.

38:12

I say risk factor in quotations here because,

38:15

uh, I don't believe gallstones are a real risk

38:17

factor. But because you end up resecting a

38:20

lot of these and a lot of patients end up having

38:21

gallstones, uh, people talk about, you know,

38:24

gallstones maybe having something to do with this.

38:27

But, you know, I think it's more just

38:28

an incidental finding because it's

38:30

such a common thing to have gallstones.

38:32

So, primary neoplasm.

38:33

That said, adenocarcinoma is by far the most

38:35

common. Squamous is the other variety,

38:37

and mets to the gallbladder are really uncommon.

38:39

Melanoma being one thing that can do it.

38:42

And on imaging, uh, you're basically gonna

38:44

see an enhancing mass in the gallbladder.

38:46

On ultrasound, uh, you know, a trapped-stone appearance

38:49

has been described, where in this case you see a small

38:51

stone over here and over here, and surrounding it,

38:54

you see this soft tissue content

38:57

with flow that sort of traps it in place.

39:00

Um, can also be a polypoid appearance, typically

39:02

greater than a centimeter, or it can also

39:04

just manifest as an area of irregular wall

39:06

thickening and not so much like a mass.

39:10

So you see this case over here on CT scan.

39:12

Not sure if this was called, but you can see a

39:14

very, very subtle, um, hyperdense lesion over here.

39:18

Very nicely seen on ultrasound as a more polypoid

39:20

mass with a little bit of internal vascularity.

39:23

Uh, and again, very nicely seen on the

39:24

MR as a soft tissue lesion with T2

39:27

intermediate signal and enhancement.

39:28

So this turned out to be an

39:30

adenocarcinoma of the gallbladder.

39:34

And oftentimes we'll see it like an

39:36

infiltrative mass that's sort of arising from

39:37

the gallbladder, but then invades the liver.

39:40

With these, I also look for adjacent

39:41

adenopathy, and also look for invasion of

39:44

the gastrohepatic or hepatoduodenal ligament.

39:46

Um, and then gallbladder neoplasms are one that

39:48

can also potentially give you carcinomatosis.

39:51

So I look closely

39:52

around the omentum at other sites

39:54

where you can see tumor implants.

40:00

How about over here?

40:00

What does the crowd think of what this could be?

40:03

This is a patient with weight

40:06

loss, post-contrast CT scan.

40:13

We have some answers come through over here.

40:16

Let's see.

40:17

This is gallbladder malignancy.

40:19

Love it.

40:20

Yep.

40:20

Porcelain gallbladder.

40:21

Yep.

40:21

I like it.

40:22

Very good.

40:22

So everyone's on the right page over here.

40:24

So, sort of interesting case. Uh, you know, people talk

40:26

about the association of adenocarcinoma or

40:29

gallbladder neoplasm and porcelain gallbladder.

40:31

To be honest, I haven't really seen it

40:33

too often sort of playing out live.

40:36

This was a case of a porcelain gallbladder

40:38

with a cancer that sort of broke through

40:40

the gallbladder and invaded the liver.

40:42

Um.

40:42

So porcelain gallbladder in itself is typically asymptomatic.

40:46

We don't really know why it happens, but the

40:48

key complication to understand is that there

40:50

is an increased risk of malignancy.

40:52

But to that, I'll only point out that

40:54

if you look at the more recent literature,

40:56

the association with malignancy is a lot less

41:00

common than what had been reported previously.

41:03

And so that association still stands, but it's not,

41:06

uh, as high as 25% that has been previously reported.

41:10

And so how do you treat these?

41:11

Well, no one really knows.

41:12

Do you sort of take it out, uh, prophylactically, or

41:15

do you treat it once, or do you screen these patients?

41:17

But I think at the very least, um, you know,

41:19

they should be evaluated from time to time,

41:21

uh, with imaging or, you know, by a surgeon.

41:24

And, uh, if they have any symptoms, they should

41:26

definitely be imaged to see if this has developed.

41:28

You can see it on the plain film as

41:29

a rim-enhancing gallbladder, a rim,

41:31

uh, calcification of the gallbladder.

41:33

And again, we've seen, I think, this

41:34

image before with calcification on the

41:36

gallbladder wall with very clean shadowing.

41:39

Good.

41:39

So that's a porcelain gallbladder with cancer.

41:42

How about this image over here?

41:45

Are we able to

41:46

come up with a very specific diagnosis for

41:48

what's causing these gallbladder lesions?

41:55

All right.

41:55

We have some answers maybe coming in over here.

41:57

Everything you need to know is on the image.

42:03

Neuroendocrine mets.

42:04

Melanoma.

42:05

I—

42:05

Like mets.

42:06

I like mets.

42:08

What's missing on these images

42:10

that's causing renal mets?

42:11

All right, so we have our answer.

42:13

Very good.

42:13

So we see that the kidney over here is missing.

42:15

We see two masses inside the gallbladder, and so

42:18

this turned out to be, uh, renal cell carcinoma

42:21

causing metastatic disease to the gallbladder.

42:22

I think the folks that said, uh, melanoma

42:25

mets would be very reasonable because

42:27

obviously it's something that commonly

42:28

metastasizes to the gallbladder.

42:31

It's one of the more common ones.

42:32

I think neuroendocrine is not a bad thought as well,

42:34

because these are clearly hypervascular tumors. So

42:36

you're on the right track, but the kidney's missing

42:38

here, and so that's the key to the diagnosis.

42:41

Very good.

42:43

So that covers the gallbladder.

42:44

And so we will now go through the second

42:47

portion of the talk, and we have about 15 minutes

42:50

left and we should be able to get through the

42:52

bile ducts, which won't have as many items in it.

42:55

And so again: anatomy, non-neoplastic, and masses.

43:01

All right, so start off with anatomy.

43:03

And this is, um, a post-contrast image,

43:06

coronal plane using Eovist at about 20 minutes.

43:09

And I'm not gonna test the crowd on the anatomy.

43:11

I just want to sort of put this out there.

43:13

If you wanna look at the recordings

43:14

after it, sort of test yourself.

43:15

This is what normal gallbladder anatomy, uh—

43:17

sorry—biliary duct anatomy looks like.

43:19

All right.

43:20

So I sort of think about the bile duct as

43:22

coming sort of from the liver to the duodenum.

43:25

So you have the, um, anterior

43:27

branch of the right hepatic duct,

43:29

the posterior branch of the right hepatic duct.

43:30

This is anterior. This is posterior.

43:33

They join to form the right hepatic duct.

43:34

Over here you have the left

43:36

hepatic duct coming over here.

43:37

This has smaller branches that are coming from

43:40

segments IV, II, and III that

43:43

are sometimes difficult to sort of delineate

43:45

because of their small size. So the right and left

43:47

come together to form the common hepatic duct.

43:49

You have the cystic duct coming over here.

43:51

This joins about here, and then

43:53

the common bile duct going down.

43:55

All right, so that's normal anatomy.

43:58

And the only reason you need to know normal

43:59

is so that you know what variants look like.

44:02

I'm not gonna go through all the variants, but if the crowd

44:04

wants to chime in on what they think this variant is,

44:07

feel free to do so.

44:11

There's only two or three variants I'll talk

44:13

about, and they end up being important

44:15

when it comes to, um, certain surgeries.

44:20

Let's see if people have come

44:21

up with an answer here.

44:25

Some people coming up with it.

44:26

So let's see.

44:27

Right.

44:28

Posterior drains to intrahepatic duct.

44:31

Good.

44:31

So certainly a problem with the right one.

44:33

And, um, this turns out to be one of

44:36

the more common variants where the right

44:37

posterior hepatic duct drains into the left

44:39

hepatic duct, and that's normal again.

44:41

So what we're talking about here is this one

44:44

draining all the way into the left hepatic duct.

44:46

And this becomes particularly important in transplant

44:49

patients where the transplant surgeons need to

44:51

know this anatomy, this variant, before they go in.

44:53

And this is a relatively common variant.

44:57

This one over here is another

44:58

variant, uh, a little bit less common.

45:00

This is on a 3D MRCP image

45:02

over here, and this one's tough.

45:04

Uh, you can see that this is the posterior duct

45:06

coming down, and whether you wanna call this a

45:08

trifurcation as I did, or whether you wanna call

45:11

it also draining to the left hepatic duct, or

45:13

right before the right anterior hepatic duct joins

45:15

in, I think I would do that, but I think about at

45:18

least one person, uh, calls it a trifurcation.

45:21

So he's in agreement with me.

45:23

I like that trifurcation pattern.

45:24

Again, that's a normal pattern.

45:27

So normally the intrahepatic ducts are less

45:29

than two millimeters in size. Common bile duct

45:32

generally six or less is good.

45:34

Um, enlarges with age.

45:35

So every decade above 60 you can add one

45:38

millimeter to the common bile duct size.

45:40

And, uh, although, you know, I've heard this has

45:42

been contested, uh, lately in that they don't—

45:45

shouldn't really enlarge post-cholecystectomy when

45:47

we see it so often that when the gallbladder's

45:49

out, the bile duct tends to enlarge.

45:50

And so we tend to, um, be a little bit more

45:53

lenient about the size of the, you know,

45:56

enlarging common bile duct, uh, particularly

45:58

if the patient is post-cholecystectomy.

46:02

Let's go through the non-neoplastic

46:03

conditions. First one over here—

46:08

If you're, uh—

46:10

you know, do any sort of abdominal MR imaging

46:13

at your institution, you're in the ER,

46:15

this is bread and butter.

46:16

Have to know what this looks like.

46:17

Coronal T2-weighted image.

46:20

Yep.

46:20

Choledocholithiasis. Perfect.

46:22

So I wanna make sure that everyone

46:23

sees what this looks like.

46:24

Um—

46:25

And a bunch of stones in the gallbladder.

46:27

We all know what that looks like. But now

46:28

we see one of these stones inside the common

46:31

bile duct over here causing ductal dilatation.

46:33

And it's important to know that MR is very

46:35

good at this, but it's not perfect, right?

46:37

So, uh, you know, you'll miss stones if they're

46:40

less than three millimeters in size, but

46:42

generally for less than three millimeters,

46:44

there’s a good chance they're gonna pass.

46:45

And so I don't, uh, lose sleep over

46:47

it if I'm missing tiny, tiny stones.

46:49

But generally, with good imaging sequences, you know,

46:52

good T2-weighted sequences and MRCP sequences,

46:54

you can catch most stones that are at least that size.

46:58

How about this?

46:59

This is a coronal 3D MRCP image.

47:02

Intrahepatic bile ducts look very

47:03

abnormal.

47:05

What does the crowd think of

47:06

what's going on over here?

47:13

A lot of answers coming in, which means—yep.

47:15

Very, very good.

47:16

All right.

47:17

Excellent.

47:18

Biliary strictures.

47:18

Yep.

47:19

Due to primary sclerosing cholangitis, right?

47:22

Primary means it's idiopathic.

47:23

Secondary is when it's seen with associated

47:26

conditions, most commonly inflammatory bowel

47:28

disease, specifically ulcerative colitis more often.

47:31

And what you see here is multifocal regions of

47:36

intrahepatic biliary ductal dilatation and narrowing.

47:40

Right?

47:40

So if we go back to this thing over here,

47:43

you can see that if you follow this duct over

47:45

here, it looks relatively normal, then you

47:47

don't see it—that's the stricturing—then it

47:48

gets dilated, then you don't see it over here.

47:50

And then potentially it connects to other

47:52

ducts over here, which look dilated.

47:54

So, you know, you see areas of narrowing,

47:55

dilatation, narrowing, dilatation,

47:57

um, typically multifocal. And, uh—

48:01

It's been described as having

48:02

a string-of-beads appearance.

48:03

It can involve both the extrahepatic ducts.

48:07

You see over here very nicely on the

48:08

ERCP image, areas of multifocal stricture.

48:11

You see this one over here where there's

48:13

a stricture, the duct is dilated,

48:14

another stricture, the duct is dilated.

48:16

So that sort of appearance is very

48:18

good for sclerosing cholangitis.

48:20

Why do we care about sclerosing cholangitis?

48:22

'Cause it can cause cholangio and over a long

48:25

period of time can also lead to biliary cirrhosis.

48:28

So we need to monitor these patients regularly

48:31

to make sure these complications are developing.

48:36

How about this one?

48:36

So I'm showing you here, T2

48:38

weighted images of the same patient,

48:40

a few different slices.

48:42

Left hepatic lobe looks very abnormal.

48:46

Um, this is a tougher case, I think, but

48:50

I have faith in the community here that

48:51

they'll come up with some good answers.

48:54

So this one's just affecting

48:55

the left lateral hepatic lobe.

48:58

So what does the crowd think over here?

49:00

Atresia.

49:01

Yeah, we got one right answer here.

49:03

Recurrent pyogenic cholangitis.

49:05

And so I think this is a tough, uh, case

49:07

to call that for, but, um, that, that

49:09

would be something to consider here.

49:10

So what we're seeing here is dilated bile

49:12

ducts, um, and we see a little fill-in

49:15

defect inside the dilated bile duct.

49:17

So that's gonna be a little stone over there.

49:19

And this has probably been going on for some

49:20

time, which is why the liver lobe is atrophied.

49:22

In fact, the same patient many years back

49:24

when the bile duct, uh, where their liver

49:26

was a little bit more healthy, had relatively

49:28

healthy-looking, uh, left lateral hepatic lobe.

49:31

And so this is what recurrent

49:33

pyogenic cholangitis looks like.

49:35

Used to have a different name,

49:36

which we don't like to use anymore.

49:37

So we can use RPC.

49:39

Recurrent pyogenic cholangitis tends to be seen in the

49:42

East Asians, and it's due to an infection with, uh,

49:45

the liver fluke or *Clonorchis*, and that results in

49:48

strictures that can result in biliary duct dilatation.

49:51

And the key imaging feature here is that

49:53

it likes the left lateral hepatic lobe.

49:56

I'm not exactly sure why.

49:57

Maybe people out in the crowd know better

49:59

reasons, but if we can commit that to memory,

50:01

left lateral lobe is a very key feature.

50:04

Those ducts are dilated and sometimes it'll

50:06

also do the posterior right hepatic ducts as

50:08

well, so that you'll see occasionally. The left

50:11

lateral lobe's the one I want you to remember.

50:13

You have ductal dilatation due to the stricturing.

50:15

And inside these ducts you can sometimes see

50:17

stones develop like you can see in this case.

50:20

And classically, you'll see intrahepatic duct stones

50:23

form typically without the presence of gallstones.

50:26

So that's another key feature.

50:27

Over time, whenever you have biliary ductal

50:29

dilatation of a lobe, that lobe does not—is—

50:31

will not be as healthy and so can atrophy.

50:34

And again, like PSC, increased

50:36

risk of cholangiocarcinoma.

50:37

So you want to be able to

50:38

monitor and call this correctly.

50:41

And so that leads us to our unknown case

50:43

number five, which was, uh, a case that, uh,

50:46

I think some of you in the crowd got as well.

50:48

And this was a, uh, you

50:49

know, a red herring here.

50:50

I suppose it just happened to be a cyst in the liver.

50:53

But what I wanted to show you here was that the

50:55

left hepatic ducts, lateral lobe, again, are

50:57

dilated and filled with multiple, multiple stones.

51:00

And so when you see something like this,

51:01

you gotta think of that diagnosis of,

51:04

um, of recurrent pyogenic cholangitis.

51:08

So this was, uh, yet another case, uh, in a

51:10

patient who had come in with abnormal LFTs.

51:15

How about this patient over here?

51:16

So this is a patient who, um, post-transplant for

51:19

10 years, had come in with fever, white count, got a

51:23

CAT scan, and, uh, we see a few masses in the liver.

51:28

So what do we think is going on over here?

51:30

Transplant patient with these masses in the liver?

51:33

What are we worried about?

51:38

Abscesses.

51:38

Abscesses.

51:39

Very good.

51:40

And so a lot of people talk about abscesses and,

51:43

uh, why do we think the patient has abscesses?

51:45

I think one person said it out

51:46

in the crowd.

51:51

So transplant patient with, with liver abscess,

51:51

1404 00:51:54,405 --> 00:51:56,505 You gotta think about hepatic artery compromise.

51:56

And so we got a CT on this patient.

51:58

You can see celiac coming out here.

51:59

Splenic artery looks great.

52:00

Look at the hepatic, common

52:02

hepatic artery cutoff over here.

52:03

And so this was a patient who had biliary

52:06

ischemia resulting in these abscesses,

52:08

bilomas due to hepatic artery thrombosis.

52:12

You can see that the interventional radiology

52:15

study also shows that. This is very important because

52:18

hepatic arteries are the sole

52:20

vascular supply to the biliary system.

52:21

So if there is any compromise to the hepatic

52:24

arteries, whether it's severe stenosis or frank

52:26

thrombosis, you're gonna have damage to the bile

52:29

ducts which become necrotic, forming these collections.

52:32

And so you have to try to fix the underlying

52:34

issue, which is the hepatic artery compromise.

52:38

And so if you don't fix it, very high mortality rates.

52:41

So whenever you see a transplant patient in

52:42

particular, because this tends to happen

52:45

in more transplant patients, but any patient

52:47

with—for whatever reason—has liver

52:49

abscesses or bilomas, you're not really sure why,

52:53

think about could there be hepatic artery compromise?

52:59

This person has history of AIDS, has a

53:01

coronal T2-weighted image, and you can

53:04

see that the bile ducts are dilated, going

53:06

all the way down to the bottom over here.

53:08

What's the most likely

53:09

reason in this patient?

53:16

A cholangiopathy.

53:16

Yeah.

53:17

And so AIDS cholangiopathy can have

53:19

multiple manifestations, and one

53:23

of these is papillary stenosis. It can also

53:25

cause a sclerosing cholangitis picture.

53:27

We've covered what sclerosing cholangitis looks like.

53:29

And it's really due to opportunistic

53:31

infections, whether it's CMV or Cryptosporidium.

53:32

So a tough diagnosis to

53:35

make without that history.

53:37

But just to know that that also is an

53:38

entity you should know about. Another non-

53:42

neoplastic condition that we see quite often,

53:44

but, uh, you know, perhaps sometimes

53:47

we don't call this as often as we should.

53:49

This is a T2-weighted image.

53:50

This is a T1 post-contrast image.

53:53

Um, and more of like an equilibrium delayed phase.

53:55

Regardless.

53:55

What do we think is going on over here?

54:00

Let's see a few people coming up with

54:02

the answer. I like peribiliary cyst.

54:05

I think a few people are

54:06

coming up with that diagnosis.

54:07

Very good.

54:08

So this is peribiliary cyst, and it's something I

54:10

remember, you know, as a trainee I didn't know about.

54:12

And I remember seeing a case on call,

54:14

and I was so excited 'cause I thought

54:16

this was biliary ductal dilatation.

54:17

There was a big cancer somewhere.

54:19

And I was excited because I thought I was gonna

54:21

make a great diagnosis, and my attending

54:23

told me no, it's just peribiliary cysts.

54:24

And so that stuck with me.

54:27

And so these are cysts of glands that

54:30

are adjacent to the intrahepatic bile duct.

54:32

They actually don't communicate with the biliary tree.

54:35

And in certain conditions, particularly cirrhosis,

54:38

you'll see that they dilate, and they tend to

54:39

dilate sort of on the central portion of the liver.

54:42

And they're not as dilated or

54:44

prevalent around the periphery of the liver.

54:46

They're small, two to 20 millimeters.

54:48

And what they manifest as is tiny

54:50

cysts that are just hugging a—

54:52

portal veins on both sides, as opposed to bile

54:55

ducts which are only gonna be on one side.

54:57

So what I'm showing you here is the cystic lesions

54:59

that are hugging the portal vein and that they're

55:01

not enhancing. The portal vein here is enhancing.

55:03

And so next time you see a patient with cirrhosis,

55:06

look particularly on the central portion of the liver.

55:08

I bet you you'll see these things

55:10

more often than you thought.

55:11

Um, this is a more exaggerated case of it,

55:13

but sometimes they can be there and be quite

55:15

subtle and, again, of no clinical importance.

55:17

But just remember that.

55:18

Don't mistake it for dilated bile ducts.

55:23

This one, I think everyone got right, even though

55:25

I thought this was a more challenging case.

55:27

But I think, uh, you know, it is what it is.

55:30

A young patient, multiple masses in the

55:32

liver, little, uh, cystic masses.

55:35

This was a dot of contrast in between "central dot sign."

55:38

Perfect.

55:38

And so this was a case of Caroli’s disease.

55:41

I don't think I've seen it as good as this.

55:43

Um, and this is, uh, due to in utero

55:45

malformation of the ductal plate, again, which

55:48

you have to be worried about, uh, because

55:49

an increased risk of cholangiocarcinoma.

55:52

The central dot sign that you can see or has

55:54

been described, I think on ultrasound, but, um,

55:57

you can see it on pretty much any modalities

55:58

you can imagine that really represents, uh,

56:01

the portal triads that are going to the center

56:03

of these, uh, dilated, uh, biliary spaces.

56:06

Another teaching point is that oftentimes with

56:08

Caroli disease, you have abnormalities of the kidney,

56:10

whether it's medullary sponge kidney or infantile

56:12

polycystic kidney disease.

56:14

So once you've sort of mastered what this looks like,

56:16

have a look at the kidneys and, uh, oftentimes you'll

56:19

see an abnormality associated with that as well.

56:24

This case over here is sort of along the

56:26

same lines, but not quite the same diagnosis,

56:28

where you have dilated intrahepatic ducts,

56:31

quite dilated, dilated extrahepatic ducts,

56:33

stone that's sort of floating in them.

56:36

And so this one.

56:42

I think is gonna be,

56:44

I think in the interest of time, if it's okay,

56:46

I'll just sort of move on, is gonna be a choledochal cyst.

56:49

I think somebody might have said it there.

56:50

And so this is sort of a congenital cystic

56:53

dilatation of the biliary tree, tends to be seen

56:55

in younger patients, and there's a possible

56:57

association with anomalous junction of the

56:59

common bile duct and the pancreatic duct.

57:01

So if you see the common bile duct and pancreatic

57:03

duct, this junction of it's greater than 15

57:05

millimeters, some people have reported that that

57:07

makes patients more prone to getting choledochal cysts.

57:11

They also have an increased

57:12

risk of cholangiocarcinoma.

57:14

There is a classification, um, of what these look like,

57:18

uh, based on where the cystic dilatation is occurring.

57:21

And you can sort of look at this even more.

57:23

In fact, there's three types of type one.

57:25

And so it's just so that it's on your radar.

57:28

This is what a choledochal cyst looks like and the

57:30

important complication associated with it.

57:35

I said bile leaks here, but I don't think I actually, I

57:37

forgot to include the case of that, so I do apologize.

57:40

We'll finish off with masses.

57:43

Diagnosis, please.

57:44

On this case, coronal 3D MRCP, multiple

57:49

T2 hyperintense masses scattered

57:50

throughout the liver over here.

57:52

What's the best diagnosis?

57:54

They're rather small in size, if that helps anybody.

57:57

Yeah.

57:57

Hemangioma?

57:58

Von Meyenburg complexes.

57:59

Biliary hamartomas.

58:00

Yep.

58:00

That's what they look like.

58:01

So key thing is here, they're quite

58:03

diffuse and they're very small.

58:05

Typically one to five millimeters, but

58:07

certainly no bigger than 15 millimeters.

58:09

They don't communicate with the biliary tree.

58:12

This is what they look like on MR imaging.

58:13

Multiple tiny, tiny T2 hyperintense

58:15

masses throughout the liver.

58:17

On ultrasound, they can be quite echogenic,

58:19

you might see a comet tail artifact.

58:20

That's just because of the small

58:21

size of the cystic lesions.

58:23

And on CT scans, actually

58:24

they're quite difficult to see.

58:26

Um, and be quite subtle.

58:27

This is actually the same patient, and you can see much

58:29

more evident on imaging and important to know what

58:31

this looks like because you don't need to treat it.

58:33

There have been some rare associations with

58:35

cholangiocarcinoma, but again, these are rare.

58:37

By and large, you see this,

58:39

call it what it is.

58:40

Don't need to worry about it, can

58:41

reassure your referring provider.

58:46

This one here is a bit of a tough one.

58:48

So I'll go through a T2 fat sat

58:49

image, a large cystic mass over here.

58:52

No real enhancement.

58:53

I'll tell you, this is the only cystic mass

58:55

in the liver, and this was, uh, I think a

58:56

67-year-old female who had this lesion with some

58:59

abdominal pain, sort of giving you that history.

59:02

Yeah, I think a cystadenoma is, uh, is

59:06

probably one thing you should think about.

59:07

And the one reason I wanted to include this case is

59:09

because, you know, I'm, to be honest, still used to

59:11

calling these biliary cystadenomas, but there is a new

59:14

nomenclature for this, so I thought I would just put

59:15

it out there for people to read about if they need to.

59:18

They're called hepatic mucinous cystic

59:20

neoplasms, and they qualify them as

59:23

being either non-invasive or invasive.

59:26

Cystic neoplasm.

59:28

These also don't communicate with the biliary tree.

59:30

They're seen in middle to older-age

59:32

women most commonly. They can be incidental or

59:34

present with pain or as a palpable mass.

59:37

By and large, most of them

59:38

will be benign or non-invasive.

59:40

On imaging, you'll see, um, usually an

59:42

isolated large cystic mass, typically unilocular,

59:45

but you may have some mural nodules within it.

59:47

You could see some papillary projections.

59:49

And as you can imagine, the more soft tissue

59:51

components you see in it, uh, that's when you start

59:54

to think if it's an invasive mucinous cystic neoplasm.

59:57

So that terminology, uh, they call these things not

59:59

biliary adenomas, but rather mucinous cystic neoplasms.

60:06

And we're almost at the end

60:07

here, patient with abnormal LFTs.

60:10

I'm showing you, uh, a coronal T2-weighted image.

60:13

This is their MRCP showing you the ductal

60:15

dilatation of very ill-defined mass.

60:17

Here you see a bunch of gallstones.

60:19

Common things being common in this

60:20

patient with abnormal LFTs and jaundice.

60:23

What do we think it is?

60:24

Yeah, it's a cholangiocarcinoma, Klatskin tumor.

60:27

And so, um, again, you can see

60:30

a portion of the mass here.

60:32

What I wanted to show in the post-contrast sequence

60:34

in the early phase, this is what it looks like.

60:37

And look at it on the delayed phase, right?

60:39

It's retaining the contrast.

60:41

It's much brighter on the delayed phase

60:42

image than it is on the earlier phase image.

60:45

So these imaging features are

60:46

classic for cholangiocarcinoma.

60:48

We've talked about some risk factors already

60:50

that, uh, contribute to it, particularly the

60:51

couple of the cholangitides that we talked about.

60:54

Um, choledochal cysts as well.

60:56

By and large, these are adenocarcinomas.

60:58

Um, when you have these biliary cancers, most

61:01

often the hilar region in the Klatskin tumor.

61:04

Um, they can also be distal in the

61:06

common bile ducts or they can be a

61:07

ill-defined mass or a polypoid mass.

61:10

And, uh, a subset of them may

61:11

also be within the liver itself.

61:14

Um, they're called intrahepatic or peripheral.

61:15

These are the least common, and the key imaging

61:18

feature is that this will retain contrast.

61:20

So you best see that on the 10-minute delayed

61:22

scan, where if you wait long enough, you'll

61:24

see it brighter on this sequence than you see

61:27

on the early arterial phase, and particularly

61:29

if it's at the periphery of the liver.

61:31

This thing likes to, uh, scar the

61:34

capsule, resulting in capsular retraction.

61:37

So if we see this image over here, ill-defined

61:40

T2 hyperintense mass, arterial phase enhancement,

61:43

really retains contrast on a more delayed

61:46

phase image, bit of capsular retraction

61:48

associated with it, and also some dilated bile

61:51

ducts that you can see, um, upstream from it.

61:54

This is a peripheral cholangiocarcinoma.

61:58

Now I'll finish off with this case.

62:00

You know, you see this case over here, multiple

62:02

areas of intrahepatic ductal dilatation, and,

62:05

uh, you know, we've seen a case like this before.

62:07

We, we called it kind of primary sclerosing

62:09

cholangitis, but just of course, remember,

62:12

uh, metastatic disease can also cause this.

62:14

If you see the T2-weighted images, this

62:16

was an esophageal cancer and unfortunately

62:17

with diffuse liver metastases causing

62:19

segmental regions of ductal dilatation.

62:24

So that covers our masses.

62:29

Now let's go back to our objectives

62:30

as we wrap up this, uh, this session.

62:32

So, uh, you know, a lot of things have been

62:34

covered and you guys did great with the unknown

62:36

cases, but really three discrete things.

62:38

I want you to get out of this.

62:39

Know what acute cholecystitis

62:41

looks like on different modalities.

62:43

Recognize its complications, particularly

62:44

'cause the complications can be

62:46

associated with high mortality rates.

62:48

Um, remember, uh, the different

62:50

cholangitides that we talked about.

62:51

PSC, recurrent pyogenic cholangitis.

62:53

What do they look like?

62:54

Compare and contrast your features.

62:56

Remember that they both put you

62:58

at a risk for cholangiocarcinoma.

63:00

And then remember what cholangiocarcinoma looks like.

63:03

Klatskin tumor is most common, the hilar location.

63:06

But if out in the periphery, can

63:08

uh, retain contrast in the 10-minute

63:10

delayed image, cause capsular retraction.

63:12

And also remember that ultimately you can suggest

63:15

that diagnosis, but it can't be a radiology diagnosis.

63:17

Unlike hepatocellular carcinoma.

63:20

You can suggest it, but they would have to

63:21

biopsy it to ensure that that is the case.

63:26

So with that, I'll wrap up this session.

63:27

Thank you all for your participation.

63:30

Um, it's been wonderful to interact

63:32

with you, and uh, thank you again

63:34

to MRI Online for hosting this today.

63:36

Thank you so much, Dr. Mathur.

63:38

Uh, we do have a couple of Q and A's. I'm

63:40

not sure on time. I know we're a little past the

63:42

hour, so I want to be respectful of that.

63:44

I'm happy to stick around for them, um, and

63:46

then try to get through as many as I can.

63:49

Um, and so let's go, I guess, to the top, I guess...

63:54

Yes, in

63:55

the Q&A.

63:55

Yes.

63:56

So shadowing of the porcelain gallbladder.

63:58

You will have some shadowing with it.

63:59

Um, you won't see that wall-echo-shadow complex.

64:02

You won't see a discrete wall.

64:03

You won't see then, you know, a stone

64:05

discrete from the shadowing posterior with it.

64:07

You will see shadowing associated with the

64:09

porcelain gallbladder. Won’t be as robust as you

64:11

see the shadowing with gallstones, but there

64:13

will be some degree of clean shadowing with that.

64:15

Um, do you ever call or suspect early...

64:18

Could cholecystitis?

64:18

You know, that's a great question.

64:20

Um.

64:21

I like to, you know, have a

64:23

bunch of different signs, right?

64:24

So I want to see gallbladder wall distension,

64:28

thickening, um, and some inflammatory change.

64:32

I think the inflammatory

64:33

change is the key thing for me,

64:34

'cause I can't call something an -itis

64:35

if I don't see inflammatory change.

64:37

But I can certainly, um, alert

64:40

my referring provider to the fact that,

64:42

"Hey, listen, there is a gallstone there.

64:43

It's impacting it. It may be

64:45

causing pain for the patient.

64:47

It may not be causing frank inflammation yet, but

64:49

that's probably... it could be the next step."

64:51

So that's something you'd have to

64:53

potentially have a discussion with,

64:54

with the referring provider.

64:56

Why was the stone hypodense on CT?

64:59

Um, as you can imagine, a large

65:02

percentage of stones don't have cal—

65:03

enough calcium or have no calcium in them.

65:05

And so that's why it can be hypodense on CT.

65:08

You don't always see them as calcified.

65:11

Um, just kind of going through as many of

65:13

these as I can. Differentiate, uh, how can

65:16

I find CBD from cystic duct and syndrome?

65:21

Um, I think, in that case, you

65:26

know, a lot of times it just depends

65:27

on how good your imaging is, right?

65:29

If you have good-quality MR imaging, by and large,

65:31

you can probably follow the cystic duct nicely.

65:33

Typically, when you have Mirizzi

65:34

syndrome with a stone impacted in the cystic

65:37

duct, the cystic duct will be dilated.

65:38

You can follow that to the gallbladder.

65:40

Um, admittedly, sometimes it can be difficult,

65:43

and maybe it's sort of protruding into

65:44

the CBD, but a lot of that will depend

65:47

on the anatomy itself.

65:51

Uh, great question by Shah. You know, to

65:54

be honest, yeah, I probably said that

65:57

you recommend surgical consult.

65:59

To be honest, the reality is, I think

66:02

about it, I probably don't recommend it as often.

66:04

But I think for people out there in the

66:06

community who don't, you know, we're at an

66:08

academic placement, we get good follow-up with

66:10

a lot of these patients, but you're out there

66:11

in the community, it would not be unreasonable

66:13

to ask somebody to look at them, and

66:15

just sort of have them on somebody's radar,

66:18

whether it's a surgeon or a primary care

66:20

doc, to just make sure that they follow them up.

66:23

If not imaging, at least clinically,

66:25

to make sure that nothing develops.

66:27

'Cause you're absolutely right,

66:28

that incidence is a lot lower.

66:30

Cancer.

66:31

I'm not sure how long I can

66:32

go. To the MRI Online folks,

66:34

I'm happy to keep on going for a little bit longer.

66:36

Um, uh, confident with dilatation on non-contrast

66:41

CT, you know, windowing is your friend here,

66:43

just, uh, window it like you do liver windows.

66:45

Play around with it and try to follow as best you

66:47

can, but, uh, can be hard to detect biliary dilatation

66:50

sometimes if you don't window appropriately.

66:54

Most important ultrasound

66:55

criteria for acute cholecystitis.

66:57

Honestly, um, positive Murphy's. That's

66:59

something that you can't rely on the

67:00

technology. You have to check yourself.

67:02

And for me, it's, um, having that

67:04

sort of hydro appearance of the

67:06

gallbladder where there's distension.

67:07

Those two things I like to look for for cholecystitis.

67:12

Uh, tiny adenomyomatosis, tiny cholesterol polyp.

67:16

Very difficult.

67:17

Um, I think the physics behind this would be a little

67:19

bit too much to explain right now, if that's okay.

67:21

But between tiny adenomyomatosis or adenomatosis,

67:24

tiny cholesterol polyp, I think if you see

67:26

thickening, you're gonna suggest it's adeno-

67:27

myomatosis versus a cholesterol polyp

67:29

would be the best way to differentiate.

67:30

But you're right, it can be tough.

67:34

I think we sort of talked about this, so I'm

67:36

gonna, I'm gonna, uh, skip that for the moment.

67:39

Alright, Dr. Mathur, let's do

67:40

two more and we can call it two

67:41

more.

67:41

Okay.

67:42

Why don't I go from the bottom, if that's okay?

67:43

I've been, um,

67:46

uh, okay.

67:47

This is a tough one.

67:48

Let me just see.

67:50

Okay.

67:51

Uh, this one I can answer quickly,

67:52

'cause I just said, if you have

67:54

gas in the gallbladder or gangrenous,

67:55

you have ischemia causing the mucosa to be ischemic.

67:59

So it's just, it's missing.

68:00

The mucosa is, um, essentially infarcted.

68:03

You don't see it, but you do see gas developing.

68:05

So that's the answer to this one.

68:06

I—this one I'll just answer,

68:09

'cause again, I can see it.

68:10

And then maybe this one, 'cause

68:11

it's also on the same page.

68:12

Variant anatomy.

68:13

You give it too much importance in daily reporting?

68:14

Yes.

68:14

Unless it's a surgical patient like

68:17

a biliary transplant patient,

68:19

I don't mention biliary variant anatomy.

68:22

But I thought I would just mention it to the

68:24

crowd in case they wanted to make sure they look

68:27

for it. And hematomas—you know, we don’t do a lot of diffusion-weighted imaging.

68:31

I can't imagine they restrict too much.

68:33

They shouldn't, in theory. But we don't do a

68:37

lot of it, so it's hard for me to sort of answer for

68:39

diffusion-weighted imaging for all our liver exams.

68:42

So I'm actually not sure about that question.

68:49

Um, so those were the two or three?

68:52

I think I did another one, but yeah, I'm

68:53

happy to stop now, and I think people have my

68:56

email here, so I'm happy to answer emails.

68:57

I may be a little bit late getting back

68:58

to people, but I'll try my best to

69:00

get back to everybody who has a question.

69:02

Perfect. As we bring this to a close, I

69:04

just want to say thank you so much,

69:05

Dr. Mathur, for being with us again today.

69:07

And thanks to all of you for

69:08

participating in our noon conference.

69:09

A reminder: this conference will be made available

69:11

on demand within the next 24 hours on MRIONLINE.com.

69:15

Please join us tomorrow, April 3rd,

69:17

at 12:00 PM Eastern Standard Time.

69:19

We'll have Dr. H back with us for a noon

69:22

conference on "Head and Neck Spaces Made Simple."

69:25

Please visit us and follow us on social

69:26

media for any updates and reminders.

69:28

Thanks again, Dr. Mathur.

69:30

Thank you.

69:31

Bye, everyone.