0:01

So this patient is a 60-year-old male

0:02

with hepatitis C and cirrhosis,

0:06

who had an indeterminate liver lesion

0:07

found on a different study and an MRI

0:10

was requested to evaluate it.

0:13

So here we have our post-contrast images, and

0:16

the lesion in question, we can see over here.

0:19

So on the T1 FATSAT post-contrast,

0:23

this is arterial, portal venous.

0:26

And equilibrium phase images, the lesion is

0:29

sort of bordering segment 4A and segment 8.

0:32

But it demonstrates certainly non-

0:35

rim arterial phase hyperenhancement.

0:38

So, you know, if we imagine the lesion

0:40

like this, it's not the whole lesion that's

0:42

enhancing, but I would say about 75 percent

0:44

of it is enhancing on the inside of it.

0:46

And so that qualifies as non-rim

0:48

arterial phase hyperenhancement.

0:50

When you look at the size, this is going to be

0:52

about 20 millimeters, so we're just going to

0:54

say it's at or equal to 20 millimeters in size.

0:57

When we look at the portal venous

0:58

phase, unequivocal non-peripheral

1:01

washout, a non-peripheral washout.

1:03

And all that means is that the inside of it

1:05

is darker than the adjacent liver parenchyma.

1:08

And when you actually look at both the

1:09

portal venous and perhaps better seen

1:11

on the equilibrium phase images,

1:12

is that little rim that's surrounding this.

1:15

So this has a pseudocapsule.

1:18

Putting all this together, this

1:20

easily qualifies as a LI-RADS 5 lesion.

1:24

Now this particular lesion has one

1:26

other imaging feature, which is

1:27

why I wanted to show this case.

1:29

If we look at the T1-weighted images performed

1:34

in this case, out of phase, and this one in

1:38

phase, we can again see the lesion over here.

1:41

It's bordering segments 4A and segment 8.

1:44

On the in-phase images, it looks like,

1:46

like this, maybe a little bit hyper-

1:47

intense compared to the liver parenchyma.

1:50

On the out-of-phase images, it is

1:52

hypo-intense, the signal drops.

1:55

And when that signal drops, that tells us

1:57

that this lesion contains fat, contains lipid.

2:03

Now, LI-RADS 5 lesion irrespective of the

2:07

fact that it contains lipid or not.

2:09

The fact that it contains lipid

2:11

adds a lot more specificity.

2:14

Um, to what this is going to be,

2:15

which is a hepatocellular carcinoma.

2:18

Lipid-containing lesions in the liver are not

2:20

common, and the two ones that we end up seeing

2:24

that are most common are probably hepatocellular

2:26

carcinoma, which is a malignant mass, and

2:29

liver adenomas, which are benign masses.

2:32

Now we've discussed adenomas

2:33

in the benign liver mass talk.

2:35

We're sort of talking about HCCs in this talk.

2:38

Very simply put, if you have

2:40

a fat-containing lesion in anybody who

2:43

has an increased risk of developing

2:46

HCC, so they have cirrhosis, they have

2:48

a history of chronic hepatitis B, etc.,

2:51

well, we're going to worry that that

2:53

reflects an HCC until proven otherwise.

2:55

Adenomas typically won't occur in patients

2:58

who have risk factors for cirrhosis.

3:00

This is typically young females who

3:03

are on oral contraceptive pills.

3:05

It could be males or females

3:08

who are on steroids as well.

3:10

These are patients who have

3:11

glycogen storage diseases.

3:14

So these are the patients

3:15

who will end up getting adenomas.

3:17

But anybody who is at risk for HCC and has a

3:20

fat-containing lesion, well, you don't have

3:23

to be worried that that fat-containing lesion

3:24

in fact reflects an HCC and not an adenoma.