0:00

So this next case is a 66-year-old male,

0:04

who had an indeterminate mass seen on, uh, CT imaging.

0:08

Also has a history of lung cancer, so they wanted

0:10

to get an MRI to figure out whether this mass was a

0:13

metastasis or something they don't need to worry about.

0:15

So we'll start looking at our MR images,

0:16

starting off with our T2-weighted images.

0:19

As you scroll downwards, we can see a few liver lesions.

0:21

However, the mass in question, you can see in the left

0:24

hepatic lobe, a rather large mass as seen over here.

0:27

On the T2 non fat-saturated image, again, we

0:30

can see a very, very large mass occupying Uh,

0:33

majority of the lateral left hepatic lobe.

0:36

Its internal contents are sort of interesting in

0:38

that a lot of it is T2 hyperintense, but there are

0:41

certain areas within it that have even

0:43

brighter T2 content that's almost very similar to CSF.

0:47

The remaining T2 content looks a little bit darker than CSF.

0:51

These findings are also well demonstrated

0:53

on the T2 turbospin echo fat-saturated

0:56

image where you have predominantly hyperintense

0:58

with certain components within it.

1:00

Even brighter than, uh, than the overall

1:03

hyperintense signal within this mass.

1:05

The next set of sequences that we need to look at are the

1:07

T1s performed both in and out of phase to see if there's any

1:10

fat or areas of increased susceptibility within this lesion.

1:14

Again, we identify this large

1:16

lesion in the left hepatic lobe.

1:18

And really, on both the out-of-phase sequence and

1:21

the in-phase sequence, the lesion looks pretty

1:23

much identical in that it's T1 hypointense.

1:27

And really, on both the T1 out-of-phase

1:29

sequence and the T1 in-phase sequence, lesion

1:32

looks identical in that it's T1 hypointense.

1:36

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

1:38

image to suggest presence of fat, and no areas of

1:41

increased susceptibility on the in-phase image as well.

1:44

Next sequence we're going to look at is

1:46

the T1 fat-saturated pre-contrast image.

1:50

What does this lesion look like on this sequence?

1:58

Predominantly T1 hypointense, you

2:00

can see this large lesion here.

2:02

And interestingly enough, if you were to look

2:04

at this very critically, those areas that were

2:06

slightly brighter on the T2-weighted images have

2:09

relatively darker signal on the T1-weighted images

2:12

compared to the remaining portion of this mass.

2:16

Up next, of course, is our post-contrast imaging that will

2:19

allow us to determine what this lesion is going to be.

2:22

So here we have our dynamic post-contrast images,

2:25

and we can see this lesion in the left hepatic lobe.

2:28

Let's talk a little bit about how this enhances.

2:31

So, if we look at this mass on the arterial phase

2:34

images, we once again can see that this lesion, like

2:37

some of the lesions we've seen so far, has peripheral

2:40

enhancement and puddling of contrast that's discontinuous.

2:43

You can see along this portion here, there's no

2:46

contrast, again, continues along this portion next to it.

2:50

On the portal venous phase images, we can

2:52

see that this contrast extends out centrally

2:54

and starts to fill in some of this lesion.

2:57

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

2:59

that much of this lesion is filled with contrast except for

3:03

those areas that were relatively bright on the T2-weighted

3:07

images and relatively dark on the T1-weighted images.

3:10

So there are certain pockets within this that

3:12

actually never fill up with contrast with

3:15

the remaining lesion filled with contrast.

3:18

And so this lesion is compatible with a T1-weighted image.

3:21

Giant, giant hemangioma.

3:26

Now the definition of giant

3:27

hemangioma differs in the literature.

3:30

Some people say it's more than four centimeters, some

3:32

people say six centimeters, I've read ten centimeters,

3:35

but generally I would say if it's more than five

3:37

centimeters it'll qualify as a giant hemangioma.

3:41

And these lesions, uh, again, can be asymptomatic like

3:45

other hemangiomas, but because of their size, they

3:47

can have some mass effect upon adjacent structures

3:50

within the liver and even adjacent to the stomach, for

3:53

example, over here, causing potentially early satiety.

3:57

One of the other things that can happen with this

3:59

lesion is something called the Kasabach-Merritt

4:02

syndrome, where there is a consumptive coagulopathy.

4:06

So the lesion is so large, it starts, um,

4:09

consuming all the clotting factors, resulting

4:12

in thrombocytopenia, so decreased platelets, and

4:15

potentially disseminated intravascular coagulation, DIC.

4:22

These sort of spaces that don't fill up with contrast

4:26

are thought to reflect these, uh, clefts within this

4:29

that could reflect central necrosis or liquefaction, and

4:32

these sometimes can be seen with these giant hemangiomas.