0:01

So this patient came to us with a history

0:03

of abdominal pain, 60-year-old female,

0:06

and has a whole bunch of things going

0:07

on, and it's quite an interesting case.

0:09

So let's have a look at it.

0:10

So actually, we're going to start

0:11

off in this instance with a CT scan.

0:14

This is done with intravenous contrast.

0:17

And as we scroll through it, you know,

0:19

we look at the liver and there's a

0:20

whole bunch of probably what looks

0:22

like liver cysts and some liver lesions

0:24

that are too small to characterize.

0:25

This large one over here looks like it has

0:27

a little bit of a thick wall, maybe some

0:30

minimal stranding within the adjacent fat

0:34

and so presumably that is causing or at

0:38

least contributing to the abdominal pain.

0:40

It's certainly larger than the other

0:41

cysts and has a little bit of signs that

0:45

suggest that it may be infected potentially.

0:47

And if that's all we see in this case,

0:51

that's fine, but perhaps it's not sufficient.

0:53

And there are a few other things going on.

0:55

A lot of the other

0:57

liver cysts are just distractors.

0:59

So I want you to notice what's

1:00

happening with the biliary tree here.

1:03

Left hepatic lobe, dilated bile ducts.

1:07

And notice that it's quite focal

1:08

here, in that we don't see bile ducts

1:10

that are dilated anywhere else in

1:12

except really the left hepatic lobe.

1:14

And specifically, if we're going to

1:15

get into the anatomy, it's really the

1:17

lateral segment of the left hepatic lobe.

1:19

So very, very focal and specific

1:22

regions of ductal dilatation.

1:24

And again, if that's the observation we

1:25

make, that would be a great observation,

1:27

but again, not sufficient because the other

1:29

observation that's subtle and that we'll

1:31

see a little bit more on the next study

1:33

that we look at in this patient is the

1:35

fact that inside these bile ducts, there

1:37

are hyperdense foci, one over here, one

1:40

over here, one over here, one over here.

1:43

So the bile ducts themselves are relatively

1:46

hypodense, but inside of them, they have

1:48

fill-in defects that are hyperdense.

1:50

And the more you look, the more you see it.

1:52

Again, some more fill-in defects here.

1:54

Let's look at these findings on the

1:56

coronal before we get to an MR image.

1:59

You can see the bile duct, the left hepatic

2:00

lobe is dilated, but look how there are these

2:02

fill-in defects that are relatively hyperdense,

2:05

filling some of these dilated bile ducts.

2:08

You can see them very nicely here.

2:10

Another one over here, this fill-in

2:11

defect with a dilated biliary tree.

2:13

And again, I want you to notice that

2:15

it's affecting really the lateral

2:18

segment of the left hepatic lobe.

2:19

All right.

2:20

This is followed by an MR.

2:22

So let's have a look at these

2:22

findings on the MRI images.

2:25

We did this without contrast.

2:26

This is just a very short study with a few

2:29

sequences to evaluate what was happening here.

2:32

T2-weighted axial image.

2:34

We can see a bunch of these cysts.

2:36

We're just going to ignore that for the moment.

2:37

I want us to focus on the bile ducts.

2:40

Let's see.

2:40

This is what we see over here.

2:43

Lateral segment bile ducts dilated.

2:45

Look what's inside these bile ducts, these

2:47

geographic T2 hypointense filling defects.

2:52

There's a whole bunch of them in the

2:53

intrahepatic biliary tree over here as well.

2:56

You can also see that large cyst over

2:58

here as a side with a little bit of debris

2:59

within it; looks a little bit thick-walled.

3:01

And so the idea that this is infected

3:03

or inflamed, I think, is very reasonable.

3:05

Why is the left bile duct dilated?

3:07

What do these filling defects represent?

3:09

You can see it on the coronal image.

3:11

As well, similar findings of dilated biliary tree

3:13

with a bunch of filling defects inside of it.

3:15

And I'm going to finish off sort of

3:17

describing these findings by having

3:18

you look at the T1-weighted images.

3:21

This is the T1 out-of-phase

3:22

image performed without FATSAT.

3:25

And just to notice that these filling

3:26

defects are actually T1 hyperintense.

3:31

And on the in-phase, T1 in-phase

3:33

images, they remain hyperintense.

3:35

All right, so T2 hypointense filling defects,

3:37

which are T1 hyperintense within dilated

3:41

bile ducts involving the left hepatic lobe.

3:43

These findings are quite pathognomonic,

3:47

and at least the entity that should

3:49

come to your mind when you see this

3:50

is current pyogenic cholangitis.

3:54

We don't see this a lot in our patient

3:56

population and it most commonly occurs

3:58

in patients of Southeast Asian descent,

3:59

of which this patient actually was.

4:02

And what you end up seeing are areas of

4:04

ductal dilatation with intraductal calculi.

4:08

That's what these filling defects represent.

4:10

We often see them in the intrahepatic ducts.

4:12

You can also see them in the extrahepatic ducts.

4:15

But for whatever reason, there tends to

4:17

be a predilection for these dilated ducts

4:20

to occur in the left lateral segment.

4:22

So if you see that left lateral segment

4:25

ducts dilated containing stones, and a person

4:28

of Southeast Asian descent, you’ve got to

4:29

think of recurrent pyogenic cholangitis.

4:32

Less commonly,

4:33

you can also see it affecting the right

4:34

posterior segment, somewhere

4:36

in this distribution over here.

4:39

Often the stones that you see with these

4:41

patients are pigmented stones, which are

4:44

T2 hypointense but also T1 hyperintense.

4:48

And so that's what we're seeing over here,

4:49

these T1 hyperintense pigmented stones.

4:52

Why does this entity occur?

4:54

It's thought to be due to an infection

4:56

with parasites such as Clonorchis or Ascaris,

5:00

or potentially even a bacterial infection.

5:03

That results in cholangitis or

5:05

inflammation of the bile ducts.

5:07

Over time, that inflammation results in strictures,

5:11

and those strictures result in stasis of bile.

5:13

It's unable to escape and empty out properly.

5:16

And anytime you have stasis of bile,

5:18

you're predisposed to forming stones,

5:21

which is what happened in

5:22

this instance with these patients.

5:24

So one of the complications associated

5:25

with this is liver abscesses, and so it's

5:27

hard to know if this itself was a liver

5:29

abscess or if this was the large cyst that

5:32

got super infected due to this overall

5:35

inflammatory process.

5:36

We really don't have prior imaging on

5:38

this patient, but nevertheless, presumably

5:41

this was causing the patient's symptoms.

5:43

And this is something that the patient

5:44

had for quite a bit of time that

5:47

was the result of that inflammation.

5:50

So this is again a nice case of

5:52

recurrent pyogenic cholangitis.