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So the following, um, patient is 62 years old,

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a female patient with a history of hepatitis C,

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has elevated liver function tests and an

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MR was done to evaluate the etiology of this.

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So here are the MR images from this exam,

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and I'm going to actually start off with

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the T2-weighted sequences in this study,

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and I'm going to focus right about here.

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So what do we see on this image?

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So this is a T2-weighted image

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with fat saturation.

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Lots of heterogeneity in this liver.

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If you see, you know, most of the right

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hepatic lobe is sort of replaced with this

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heterogeneous sort of increased T2 signal.

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I'm talking about all this stuff over here,

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all this stuff over here, and the way to

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kind of tell that it's abnormal is just you

0:48

sort of compare it to signal in the liver

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over here, which is relatively darker.

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And if you look at this.

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This is quite a bit brighter.

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In the midst of all this, you have what

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looks like a dominant lesion in the right

1:00

hepatic lobe with rounded borders, so we'll

1:02

evaluate that in the post-contrast images.

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And the other thing you see when you

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kind of scroll up and down through this

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is that you don't really see the normal

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flow voids that you expect to see in

1:13

portal veins that contain flowing blood.

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So on T2-weighted images, when you have

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flowing blood such as you see in the aorta

1:19

over here or the IVC that looks slit-like, but

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it's certainly patent in this, in this cut.

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Flowing blood will have dark signal,

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just like this, hypo-intense signal.

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So should the portal vein, but

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you don't see the portal vein.

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In fact, you see the outline of what could

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reflect the portal vein over here, but it's

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filled with that very heterogeneous signal that

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is almost contiguous with that heterogeneous

1:39

signal that you see in the right hepatic lobe.

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And again, just compare it to the left hepatic

1:44

lobe, where the signal is relatively normal.

1:46

So let's look and see what this looks

1:48

like on the post-contrast images.

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So here we have the post-contrast images

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in our patient, uh, T1, FATSAT, post

1:55

contrast, arterial phase, portal venous

1:57

phase, equilibrium phase over here.

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And I'll, uh, first focus on that

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dominant mass in the right hepatic lobe.

2:05

We can see it over here.

2:07

Quite heterogeneous, but definitely demonstrates

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non-RIM arterial phase hyperenhancement.

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Right, the inside of it.

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Not necessarily all of it, but the

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majority of it over here and over here

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and over here demonstrates enhancement.

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It's a very large lesion.

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It's certainly well above that

2:24

threshold of 20 millimeters.

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When we look at the portal venous

2:27

phases, the same areas that demonstrated

2:29

arterial phase hyperenhancement become

2:32

darker than the liver parenchyma.

2:34

So there is definite washout.

2:36

And there's a very, very thin

2:38

capsule that surrounds this lesion.

2:40

So a capsule is also present.

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So this easily qualifies as a LI-RADS 5 lesion.

2:47

But in addition to these findings, I

2:49

want to focus back on that finding that

2:51

we saw in the T2-weighted images of lack

2:54

of that flow void in the portal vein.

2:56

So that tells us that there's something inside

2:58

the portal vein that's obstructing flow.

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If we look at the post-contrast images,

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this is the outline of the left portal vein.

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Look at the signal inside of it.

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It looks so similar to the

3:08

signal of this tumor over here.

3:10

Both arterial hyperenhancement

3:12

and washout associated with it.

3:14

So this finding is

3:15

characteristic of tumor thrombus.

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So if we were to look at this patient and

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identify that this reflects tumor thrombus,

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this straight away qualifies this patient

3:27

with a LI-RADS tumor in vein category.

3:33

TIV, that we alluded to in the

3:35

introduction to the LI-RADS lexicon.

3:38

Now, as I said, patients without LI-RADS

3:40

tumor in vein findings usually have a lesion

3:44

associated with it in the liver, and that

3:45

lesion doesn't always meet imaging criteria

3:47

for HCC, so it may warrant a biopsy.

3:50

In this instance, this lesion actually does

3:53

meet criteria for hepatocellular carcinoma,

3:55

so it probably wouldn't need a biopsy.

3:56

And if we were to, Sort of put

3:57

this all together, it would be a

3:58

large HCC, which is associated with

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tumor thrombus in the portal vein.

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It would still, though, qualify as a

4:04

LI-RADS tumor and vein thrombus category.

4:08

And another finding in this patient, which

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is nice to see because it differentiates

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tumor thrombus from bland thrombus,

4:14

is the finding of bland thrombus.

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So let's see what that looks like.

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And we'll focus sort of on the main portal vein

4:20

as it enters the portomesenteric confluence

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Normally, this should enhance with contrast,

4:25

but here, we don't see that enhancement.

4:27

In fact, we see a filling defect

4:29

that is occupying that portal vein.

4:32

So this, in fact, represents thrombus as well.

4:35

But notice that the inside of it looks so dark,

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it looks so dark, you know, when you compare

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it to that tumor thrombus that you saw, that

4:43

actually had somewhat gray signal within this.

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So when you see this sort of dark

4:47

signal within the portal vein, this

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is going to reflect bland thrombus.

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When you see signal within the portal vein

4:56

that looks grayer in signal, such as over

4:58

here, this is going to reflect tumor thrombus.