0:00

This next case is a 46-year-old female with a history

0:04

of colon cancer for which a staging CT was performed.

0:08

As we scroll through these images, we see

0:09

a whole bunch of liver lesions that are

0:11

really indeterminate in their appearance.

0:14

The first one we can see along the

0:15

posterior aspect of the right hepatic lobe.

0:17

It's quite small and very difficult

0:19

to accurately characterize.

0:21

As you scroll downwards, we can see a larger lesion

0:23

within the lateral left hepatic lobe over here.

0:26

Also, indeterminate based on its CT imaging, uh, appearance.

0:30

And so for this reason, an MRI was, uh,

0:32

performed in order to characterize these lesions.

0:35

So we'll start our MR evaluation of these

0:38

lesions with our T2-weighted sequence.

0:41

On this sequence, you can see that the lesion

0:43

more posteriorly has hyperintense T2 signal.

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It's not as bright as CSF, but certainly,

0:49

um, somewhere in between the signal you

0:51

see within the CSF and within the spleen.

0:54

By and large, when I see this type of signal,

0:56

I'm more or less reassured that this is going

0:58

to be something I don't need to worry about.

1:00

As you scroll downwards, we'll see the other lesion.

1:03

This lesion, too, is noted to have

1:05

relatively hyperintense T2 signal.

1:07

Once again, not as bright as the CSF, but certainly

1:12

brighter than what we would see in the spleen over here.

1:14

And so, again, this sort of T2

1:15

signal is somewhat reassuring for me.

1:18

However, we can't rely on this alone, and we have to look

1:21

at our additional sequences in order to characterize this.

1:24

The next set of sequences that we look at are

1:26

the T1 in-phase and out-of-phase sequences.

1:29

As we scroll downwards, I'll just focus

1:30

on the larger of the two liver lesions.

1:32

On the out-of-phase sequence over here,

1:34

you can see that it's T1 hypointense.

1:36

On the in-phase sequence over here, similarly,

1:39

you can see that the lesion is T1 hypointense.

1:41

There's no signal loss in the out-of-phase image to

1:44

suggest that it contains fat, and there's no signal

1:46

loss in the in-phase image to suggest that it contains

1:49

content that causes increased susceptibility,

1:51

like metallic content or um, clip symbolization coils,

1:56

anything like that, no gas within this lesion either.

1:59

We'll then move on to our T1-weighted fat

2:01

saturated pre-contrast imaging sequence

2:04

to see what this lesion looks like.

2:06

So on this sequence, we can also see

2:09

that this lesion is T1 hypointense.

2:12

It doesn't contain any hyperintense T1 content,

2:16

such as methemoglobin, proteinaceous debris,

2:18

melanin, And so then we have to evaluate and see

2:21

what it looks like on the post-contrast images.

2:24

So here we have our post-contrast images.

2:26

We'll once again focus on the lesion in question.

2:29

And the enhancement pattern in this case is

2:31

quite familiar, uh, as we've seen it before.

2:35

On the arterial phase, we can once again see

2:38

that this lesion over here has peripheral

2:41

discontinuous puddling of contrast.

2:44

On the portal venous phase image, we can see that

2:47

this, uh, lesion has more centripetal enhancement.

2:51

Some of the enhancement becomes, uh, a little bit more

2:53

prominent, like over here and over here and over here.

2:56

And finally, on the equilibrium phase

2:58

images, we can see that this lesion almost

3:00

is completely filled up with contrast.

3:03

So once again, this is an example of a hemangioma.

3:06

And I wanted to show this case, To sort of showcase that

3:10

oftentimes these hemangiomas can be first detected on CT

3:15

imaging or ultrasound imaging as we've seen in prior cases.

3:18

And this is a good example of how MRI could

3:20

be used in order to definitively characterize

3:24

these lesions, um, as this benign entity.

3:27

So what does this lesion do on

3:28

the dynamic post-contrast images?

3:32

Well, the enhancement pattern is somewhat

3:33

familiar as we've seen it in a prior case already.

3:38

again, in the left hepatic lobe.

3:40

On the arterial phase image, it demonstrates

3:42

peripheral discontinuous puddling of contrast.

3:47

On the portal venous phase, you can see that some of those

3:50

puddles of contrast start to extend more centrally, i.e., centripetal enhancement.

3:53

And finally, on the equilibrium phase, we can see that

3:56

the lesion further continues to enhance centrally.

3:59

And the majority of it now is filled with contrast.

4:02

So these imaging features are

4:07

characteristic of hepatic hemangiomas.

4:10

And this case showcases how you can use MRI imaging to

4:13

evaluate these hemangiomas when they have an indeterminate

4:16

imaging appearance first detected on CT imaging.