0:01

Our next patient is a 40-year-old female

0:03

with a history of breast cancer who's

0:04

getting a routine staging study, um,

0:08

to evaluate for metastatic disease.

0:10

We'll start off with, uh,

0:11

the CT scan of this patient.

0:13

So we'll go right over to the abdomen.

0:15

As we scroll through some of the first

0:16

abdominal images, we see that there

0:18

is a lesion in the liver right up the

0:20

hepatic dome, relatively hypodense.

0:24

Um, and based on this image alone,

0:26

it has a nonspecific appearance.

0:28

And for that purpose, uh, an MRI was

0:30

requested to try to characterize this.

0:33

So we'll start evaluating our MR images by

0:36

looking at the T2-weighted sequence with

0:39

fat saturation, and we can see the lesion

0:41

here right at the hepatic dome segment 8.

0:45

And it has this sort of intermediate to

0:47

slightly sort of hyperintense T2 signal.

0:52

If we look at the T2 signal,

0:53

it's certainly nowhere below

0:55

near as bright as the cerebrospinal fluid

0:57

here, so it doesn't have any T2 signal

1:00

that can reassure us that it's something

1:02

benign like a cyst or a hemangioma.

1:05

If anything, that T2 signal is similar

1:07

to the spleen, so that tells us that this

1:09

may be something we need to worry about.

1:12

Also seen partially on this image is the

1:14

patient's breast cancer here in the left breast.

1:17

Let's proceed to the in and out of phase images

1:19

to see if this lesion contains any fat, and so

1:22

here we have the T1 out-of-phase image, here

1:25

we have the T1 in-phase image, and the lesion

1:28

is essentially identical in its appearance

1:30

on the out-of-phase and in-phase images.

1:33

It is hypointense with respect to the

1:35

liver parenchyma; there is no signal loss

1:38

on the out-of-phase image within this

1:40

lesion to suggest the presence of fat.

1:42

And finally, if we look at our post

1:44

contrast images, this is a T1 fat-sat

1:47

post-contrast arterial phase, portal

1:50

venous phase, equilibrium phase.

1:52

We can see that this lesion has rim enhancement.

1:57

Right, so the periphery of

1:58

this is enhancing quite avidly.

2:00

Unlike a lot of the lesions that we've

2:02

seen so far that we've described as non

2:05

rim-like arterial phase hyperenhancement

2:07

where the central portion is enhancing.

2:09

This has a rim enhancement.

2:11

That rim enhancement is somewhat persistent

2:14

on the portal venous and equilibrium phases,

2:16

and the actual internal aspect of this lesion

2:19

itself enhances a little bit, probably low-level

2:21

enhancement, but doesn't enhance that much.

2:25

These imaging features are characteristic

2:28

of a hypovascular liver metastasis.

2:34

This happens to be a

2:36

metastasis from breast cancer.

2:39

As you can see, it looks quite different than

2:42

what we've seen with hepatocellular carcinomas.

2:45

It also looks quite different than what

2:46

we've seen, uh, for cholangiocarcinomas,

2:49

which has progressive enhancement among

2:52

the different, uh, phases, and looks quite

2:54

different from hypervascular tumors, which

2:57

enhance avidly in this, uh, arterial phase

2:59

over here, and subsequently look darker on the

3:02

portal venous and equilibrium phase images.