0:00

So this next case is a 63-year-old female with an

0:03

indeterminate liver mass for which an MRI was requested.

0:07

We'll start off by looking at our T2

0:08

weighted imaging sequences, and we can see

0:11

a very large mass in the left hepatic lobe.

0:14

On the T2-weighted imaging sequence without fat

0:17

saturation, we can see that the borders are pretty well

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defined over here, and that there is a very discrete

0:25

rim of T2, and that there is a very discrete rim of T2.

0:27

Hypointense signal.

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Internally, this looks very complex.

0:32

There are multiple areas of

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curvilinear T2 hypointense signal.

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Interspersed within these areas are areas of

0:39

more hyperintense to intermediate T2 signal.

0:42

These findings are re-demonstrated on the T2

0:45

turbospin echo fat-saturated image where we have

0:48

that discrete T2 hypointense rim with sort of these

0:52

wavy areas, curvilinear areas of more hypointense

0:55

signal and more intermediate signal seen elsewhere.

0:58

If we scroll downwards, we can see that this portion

1:01

of the mass, once again, contains sort of curvilinear

1:05

areas of hypointense T2 signal, but also has areas

1:08

that look more discretely cystic, like there's

1:12

a cluster of cysts along the periphery of it.

1:15

Next up, we're going to look at

1:16

our in-and-out of phase images.

1:18

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

1:20

we have the in-phase image, and it looks

1:22

pretty identical in both imaging sequences.

1:24

It's relatively T1 hypointense with

1:27

respect to the liver parenchyma.

1:29

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

1:31

images to suggest that this contains any fat.

1:34

Some of this stuff that you're seeing here is

1:35

all going to be artifacts, so we can ignore that.

1:38

And on the in-phase image, nothing to suggest that there

1:40

is any substance that produces increased susceptibility.

1:44

Next up, we're going to look at the pre-contrast

1:46

images to see what the lesion looks like.

1:49

Here we have the T1 fat-saturated pre-contrast

1:54

image, and again, this large mass, left hepatic lobe.

1:57

Overall, it's probably T1 hypointense with respect to

2:01

the liver parenchyma, but it has heterogeneous signal.

2:04

And if we were to sort of look at this very closely Uh,

2:06

critically, we'll see that there are areas within it,

2:08

for example here, that have a relatively brighter signal.

2:11

So maybe there's a little bit of hemorrhage

2:14

or protein within portions of this mass.

2:17

And finally, we'll look at the, uh,

2:19

dynamic post-contrast sequences.

2:21

And because of the presence of possible T1 hyper

2:24

intense content, I'm going to skip over and go

2:26

directly to the subtraction sequences that eliminate

2:29

any T1 hyperintense content so that we can see

2:33

if there's any enhancement within this lesion.

2:36

And really, on the arterial phase images, the portal

2:39

venous phase images, the equilibrium images, this lesion

2:42

looks pretty identical in that internally it is avascular.

2:48

The rhythm of it, over here and over here and

2:50

even on the arterial phase, demonstrates some

2:52

enhancement, but internally there's no enhancement.

2:55

This over here is just a pulsation artifact

2:57

from the aorta, so we can ignore that.

3:00

So, This really amounts to an avascular, large,

3:04

complex mass that replaces the left hepatic lobe.

3:07

We note that the rim is quite T2

3:09

hypointense and well defined.

3:11

We note that around the periphery of it, there

3:13

are a cluster of more cystic lesions and that

3:15

there are wavy lines seen internally within it.

3:17

This patient happens to be from Turkey

3:20

who came for an imaging evaluation.

3:22

And so, given the imaging appearance, given where the

3:24

patient has lived and has come from, the suspicion was for

3:27

a ruptured echinococcal cyst that had undergone internal

3:31

rupture, and that indeed is what this turned out to be.