0:01

Here we have a patient who is a 50-year-old

0:04

gentleman with worsening liver function tests,

0:07

and an MRI was obtained to evaluate for this.

0:10

I'm going to start off using

0:11

the axial T2-weighted sequence.

0:14

As we scroll downwards from the

0:16

sequence, I'm going to focus on the bile

0:19

ducts in the intrahepatic biliary tree.

0:22

It's tough to really see if something

0:23

objectively is going wrong here.

0:25

If you were to look at it very critically

0:26

on this slice, oh, maybe there's some bile

0:28

ducts that are a little bit dilated, but

0:30

I'm not going to draw any conclusions yet.

0:33

Right on this slice, you start to see

0:34

something here that looks a little bit dilated.

0:36

So that could be a dilated bile duct.

0:38

Maybe even this one; it's hard to know.

0:40

Maybe even this one over here.

0:41

So there's something, there are some clues

0:44

that maybe something is going wrong here.

0:47

On this slice, you can see a little bit

0:49

of the bile ducts that are dilated here,

0:50

but they're not completely dilated.

0:52

It's just one small segment

0:53

of it that's dilated.

0:54

Similarly, posteriorly over here, and on this

0:58

slice, you can definitely see the right hepatic

1:00

ducts that are quite, quite dilated, right?

1:02

So something's happening here where some

1:04

of the intrahepatic biliary tree is affecting

1:07

certain segments that look a little bit more

1:08

dilated than they should be, right?

1:11

If we sort of follow this all the way down

1:12

the extrahepatic biliary tree over here.

1:14

looks fairly okay, and we can follow

1:17

it to the ampulla fairly nicely.

1:19

This whole area here was just a little bit

1:20

of an artifact, probably a focus of gas.

1:24

Notice how it's non-dependent as opposed

1:26

to a stone, which would be dependent.

1:29

Let's evaluate the same findings but

1:31

on the coronal plane, and then we'll

1:32

start looking at some more sequences.

1:34

As we scroll through the coronal plane, I'm

1:36

going to magnify for a second; you can see

1:38

that there are some bile ducts here that look

1:40

a little bit dilated, some bile ducts here

1:43

that look a little bit dilated. You know,

1:46

some bile ducts here that might be dilated,

1:48

some bile ducts here, one over

1:50

here that's quite dilated, and even out in

1:53

the periphery, some ducts that are dilated.

1:55

So again, I think the conclusion is probably

1:58

very similar, but we're just viewing

2:00

everything in a very different plane.

2:02

We also did an MRCP sequence over here.

2:05

So let's just have a look at that.

2:07

And this is sort of a 3D MIP of the sequence.

2:10

And I think this in itself is very instructive.

2:13

And what this shows us is that the extra

2:15

hepatic biliary tree looks fairly okay.

2:18

The right hepatic duct here is a little

2:20

bit dilated, but then look what happens.

2:22

You can't follow it all the way through.

2:24

In fact, it's sort of almost missing, but then

2:26

you see it again over here, and it's dilated.

2:28

And then maybe it's missing again.

2:30

And then you see it again,

2:30

more distally, and it's dilated.

2:32

Similar pattern involving other

2:34

portions of the bile ducts.

2:35

Over here, it's relatively small in

2:37

caliber, but then it's dilated again.

2:39

Similarly over here, similarly in the

2:41

left hepatic lobe, where, you know,

2:43

you have certain segments

2:44

of ducts that are dilated and other

2:46

segments that you don't see well at all.

2:48

Another sequence that I like to use in order to

2:51

evaluate, particularly the intrahepatic bile

2:53

ducts, is actually T1 post-contrast images.

2:57

And so here we have our T1 axial T1

3:00

post-contrast images, and they're sort of stacked up.

3:03

You have the arterial phase first, in which

3:06

you can certainly see some abnormalities.

3:08

Look at the bile ducts here

3:09

that are a little bit dilated.

3:11

Look at this bile duct here that's dilated.

3:13

There's some heterogeneous enhancement

3:15

globally of the liver parenchyma.

3:16

You can see another bile duct here that's

3:18

dilated, one over here that's dilated.

3:20

Let's look at it now in the oral venous phase.

3:23

And what you're starting to see is

3:24

that there are multifocal regions of

3:27

intrahepatic biliary ductal dilatation

3:31

over here, over here, over here.

3:34

And what's interesting, as opposed

3:37

to some of the other cases that we've

3:38

seen, for example, choledocholithiasis,

3:40

is it's not uniformly dilated.

3:43

So we have a duct that's dilated

3:44

here, and then it narrows over here.

3:46

You hardly see it, maybe only

3:48

a sliver of it over here.

3:49

And then again, you see

3:50

it dilated over here.

3:52

And you see that pattern almost

3:54

everywhere in this liver.

3:55

Again, dilated ducts over here, but then they

3:58

get narrowed again; you can hardly see them.

4:00

And the extrahepatic biliary tree, if

4:02

you follow it, looks fairly okay.

4:05

And so this pattern

4:07

of multifocal regions of intrahepatic

4:09

biliary ductal dilatation and

4:11

narrowing is quite characteristic

4:14

of primary sclerosing cholangitis.

4:18

Right.

4:18

This is an idiopathic inflammatory condition.

4:22

It's thought to be potentially immune-mediated.

4:26

And it affects the biliary tree.

4:28

It can affect the intrahepatic ducts,

4:29

it can affect the extrahepatic ducts,

4:30

it can affect both at the same time.

4:33

There's a strong association

4:34

with this in ulcerative colitis.

4:36

If you're looking at patients with ulcerative

4:37

colitis, always remember to look at the

4:39

intrahepatic tree to look for this entity.

4:43

There is an increased risk of developing

4:45

cholangiocarcinoma, and I'll talk a

4:47

little bit about what that looks like

4:48

in another case in this master course.

4:51

And it's often seen in males about

4:55

30 to 40 years of age, so that's sort

4:56

of the patient demographic, so it can

4:58

be seen in any number of patients.

5:00

And over time, because you have these areas

5:02

of biliary stricturing, you have impaired

5:04

biliary excretion, and that can

5:06

result in atrophy in portions of the liver.

5:10

The caudate lobe, oftentimes as a result,

5:12

can actually hypertrophy, so it's a very

5:14

characteristic rounded appearance of the liver;

5:17

it can almost look quite cirrhotic, but it has

5:20

itself a very specific appearance where you

5:22

have enlargement of the caudate lobe and atrophy

5:25

of some of the other more hepatic segments.

5:28

And so once again, this is a case of primary

5:31

sclerosing cholangitis, multifocal intrahepatic

5:34

biliary ductal strictures with resulting

5:37

regions of focal intrahepatic ductal dilatation.