0:01

So this patient's 55 years old,

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female with bacteremia and sepsis,

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and they're looking for etiology.

0:08

They got a CT scan of the abdomen and pelvis.

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And so I'll start off by just showing you this.

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As we look at these, I want

0:17

you to focus on the biliary tree.

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And one of the things that we can notice

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is that it sort of looks like the bile

0:24

ducts are dilated, that you're seeing them.

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You're seeing a lot of them, both the right and

0:29

left hepatic ducts, right over here,

0:32

this hypodense stuff, and they look quite dilated.

0:36

And I think if that was the initial

0:37

interpretation, that's not unreasonable.

0:40

If you look at it a little bit more

0:41

closely, it is a little bit unusual

0:43

for these to be bile ducts, in the sense

0:45

that typically bile ducts are not present

0:48

on both sides of the portal vein.

0:50

They're usually just on one side of the

0:52

portal vein, whereas this abnormality

0:54

that we're seeing is actually sort of

0:56

surrounding both sides of the portal vein.

0:58

So that should clue you in that maybe

1:01

this is something else going on.

1:03

And if you were to look at it very

1:04

closely, and I submit to you that it's

1:07

tougher to look at it on the CT scans.

1:09

It almost looks like these aren't discrete

1:12

tubular bile ducts, but rather whatever

1:15

this is, is made up of multiple sort of

1:17

round spaces, like one thing over here

1:19

and potentially one thing over here and

1:21

potentially one thing over here that are

1:22

just sort of clustered together, giving the

1:24

appearance of sort of a tubular structure.

1:27

Nevertheless, you know, I think it's tough

1:29

to sort of evaluate this finding just on CT

1:32

imaging, and so we'll look at this on MR,

1:35

and so the patient's T2-weighted image, and we can

1:40

see that, again, there is this T2 hyper

1:45

intense structure is present within the liver.

1:49

That observation that we had made on the CT

1:52

scan, I think is better seen on this image.

1:55

That's the portal vein over here.

1:57

And we can see that this abnormality is

1:58

present on both sides of the portal vein.

2:00

And if you were to look at it very

2:02

critically, you'll notice that much of this

2:04

abnormality is composed of very discrete

2:06

cystic spaces that are almost clustered

2:09

up against each other rather than,

2:12

you know, a tubular structure in and of itself.

2:15

And so, when you see these findings,

2:18

one of the things you have to think about

2:19

is this entity of peribiliary cysts.

2:23

And peribiliary cysts are a dilatation

2:26

of glands within the periductal tissue

2:30

of the bile ducts, but they don't have a

2:32

communication to the biliary tree itself.

2:35

In fact, if you look at this image,

2:37

you can see the right hepatic duct,

2:38

the anterior branch and the posterior branch

2:40

look relatively normal, and that this

2:43

abnormality here is sort of separate from it.

2:46

Now this is an uncommon entity,

2:47

but when we do see it, we often see it in

2:49

the setting of chronic liver disease,

2:52

and they can increase over time with

2:55

progression of patients who have cirrhosis.

2:57

And the reason I wanted to show it is

2:59

because it's a finding that at least on CT

3:02

imaging and sometimes on MR specifically

3:06

if you're not aware of the entity,

3:08

it can look like biliary ductal obstruction.

3:11

Having them in and of itself

3:12

is of no clinical importance.

3:14

And what you're really looking for is

3:16

clusters of cysts that are hugging the

3:19

portal veins that are on both sides of the

3:20

portal veins and they tend to be concentrated

3:23

sort of along the center of the liver.

3:25

And with very little that is evident

3:28

along the periphery of the liver.

3:30

So when you see these sorts of findings,

3:32

particularly in patients who have

3:33

cirrhosis or chronic liver disease,

3:35

you've got to think of peribiliary cysts.