0:01

So this patient is a six-year-old male.

0:03

History is chronic pain, and they've gotten

0:05

an MRI to evaluate the potential etiology.

0:09

So I'm going to start off with the axial and

0:11

coronal T2-weighted images to get a lay of

0:14

the land and see what we're dealing with here.

0:16

As you scroll downwards, I'm going to

0:18

focus on the bile ducts, and we can see

0:22

that the intrahepatic ducts are dilated.

0:24

Small dilated ducts here, larger dilated

0:26

ducts in the left hepatic lobe, but as they

0:28

sort of come together, we can see that there

0:29

are multifocal regions of ductal dilatation.

0:32

You can see the extrahepatic biliary

0:34

tree here as you go downwards.

0:36

You can sort of see it here,

0:38

sandwiched in between other structures.

0:42

Generally more difficult to see and probably

0:44

a relatively normal caliber, more distally.

0:46

I think the most pronounced areas are

0:48

sort of the right hepatic ducts and the

0:50

left hepatic ducts that look dilated.

0:53

On the coronal T2-weighted images,

0:55

same findings, we can see the

0:56

intrahepatic ducts are quite dilated.

0:57

The common hepatic duct looks

0:59

relatively normal in caliber.

1:01

And as you go downwards, the common bile duct

1:04

looks relatively normal in caliber, but it's

1:06

surrounded by a bunch of these structures, which

1:07

we're going to focus on in a couple of minutes.

1:10

This is the MRCP sequence.

1:12

Again, mildly dilated intrahepatic

1:14

ducts, extrahepatic biliary tree,

1:16

relatively normal in caliber.

1:18

But as a side, I just want you to

1:19

notice that the borders of it look

1:21

sort of wavy in their appearance.

1:23

They don't quite look straight

1:24

as we've seen it before.

1:25

They almost have an undulated appearance.

1:28

Let's look at some post-contrast sequences.

1:30

This is an axial T1-weighted image with

1:32

fat saturation done with intravenous

1:35

contrast in the portal venous phase.

1:38

And we can see that the bile ducts are dilated.

1:41

Normally, you really shouldn't be

1:41

able to see any of these bile ducts.

1:43

They're definitely dilated.

1:45

Very evident in the left hepatic lobes

1:47

as well as the right hepatic lobes as

1:49

you're getting towards the porta hepatis.

1:51

And as you go downwards, you can see that the

1:54

biliary caliber is probably relatively normal.

1:59

But what you're starting to really see in

2:00

here that's abnormal is surrounding these

2:02

bile ducts are numerous vessels, right?

2:07

They are covering them, completely

2:09

encircling them over here.

2:10

And going all the way down, they're

2:12

completely surrounding these bile ducts.

2:14

And, you know, as we sort of go through this,

2:17

uh, systematically, at some point, you're going

2:19

to want to look at the portal veins in these

2:21

patients to make sure they're patent.

2:24

And it's really tough to see

2:26

the main portal vein over here.

2:28

And in fact, this main portal vein

2:30

has been thrombosed in the past.

2:31

And all these vessels that you're seeing

2:33

are collateral vessels as a result of that.

2:37

And this appearance is known as cavernous

2:40

transformation of the portal vein.

2:42

Now that in and of itself

2:44

is not that big a deal.

2:46

We do see it from time to time.

2:48

But what's sort of unusual in this case is the

2:50

fact that these vessels are enveloping the bile

2:53

ducts so dramatically that the biliary tree

2:56

is in fact dilated due to some degree of mass

2:58

effect from these dilated collateral vessels.

3:02

And so that entity is

3:04

called portal biliopathy.

3:06

And it's quite uncommon, but it's something

3:09

to just think about whenever you see

3:11

cavernous transformation of the portal veins.

3:13

Are they having some sort of

3:14

effect upon the bile ducts?

3:16

And so essentially it's a biliary

3:18

obstruction due to cavernous

3:19

transformation of the portal veins.

3:21

And one of the appearances that

3:23

has been described on MRCP is a

3:25

wavy appearance of the bile ducts.

3:27

And I sort of like this case because, you know,

3:29

if you look at this bile duct over here, you

3:31

almost get the sense of that wavy appearance.

3:34

And, you know, I sort of refer to it as

3:35

the sort of undulated borders, but

3:37

that's the same sort of appearance.

3:38

It's just the vessels that are causing

3:40

mass effect that are resulting in that

3:43

wavy appearance that we can see over here.

3:45

We can see that a little bit

3:46

on the coronal MRCP images.

3:47

These are some of the vessels here

3:49

that are causing mass effect.

3:50

And I think very nicely on our T2 coronal

3:52

weighted images, where you can see much

3:54

of these vessels that are really,

3:57

you know, causing some degree of mass

3:59

effect upon the bile duct, the extrahepatic

4:01

biliary tree, resulting in upstream ductal

4:04

dilatation of the intrahepatic bile ducts.