0:01

This was a patient where the clinical history

0:03

was COM versus cholesteatoma.

0:08

So we're going to focus on the left side

0:10

of the temporal bone in this case.

0:13

And I always like starting at the external auditory

0:16

canal, cartilaginous portion and bony portion.

0:19

And that leads us to the middle ear cavity.

0:22

In this case,

0:22

what we see is something within the external

0:26

auditory canal, and that's a myringotomy tube.

0:28

So you're seeing a tubular structure,

0:32

which is right here,

0:34

which is going to the tympanic membrane right here.

0:40

And that is one of the potential treatments for

0:44

a patient who has chronic otitis media.

0:47

However,

0:48

as you can see clearly within

0:50

the mastoid air cells,

0:52

there is a large pocket here where there's

0:55

loss of the mastoid air cell septation.

0:59

Now.

1:00

In the acute setting with a patient

1:02

who had acute inflammation,

1:04

we might think of this as coalescent mastoiditis.

1:08

However, the history was chronic otitis media.

1:11

And this is likely that the patient is having

1:15

hearing loss but is not having irritation, pain,

1:19

infection, active infection.

1:21

So when we have a soft tissue mass that is eroding

1:25

bone and eroding the septations where

1:28

it's not in the acute setting,

1:30

we have to worry about a cholesteatoma.

1:33

So likely a cholesteatoma in the mastoid antrum,

1:38

and then we look in the middle ear cavity and we see

1:41

some soft tissue around the middle ear cavity.

1:44

But more importantly,

1:46

what we're seeing is abnormal configuration

1:51

of the middle ear osticles.

1:53

So let's try to find that ice cream and

1:55

ice cream cone. So here we are.

1:57

We have kind of a conglomerate

2:00

of the ice cream and just a portion

2:04

of the ice cream cone.

2:06

That's because this cholesteatoma has eroded

2:09

the short process of the incus.

2:12

So we never see that ice cream cone.

2:16

Not only that,

2:17

but we have some element of labyrinthosipicans,

2:20

in this case fusion of the malleus to the short

2:26

process of the incus with a poorly defined joint.

2:30

And that is because of the chronic inflammation

2:33

causing osteitis, if you will.

2:35

The long process of the incus is seen here.

2:41

We have neck of malleus and long process of incus

2:44

and we have the connection to the capitulum.

2:47

And the crura of the stapes are

2:50

also identified here and here.

2:53

So maybe I'll magnify that up just to make sure that

2:55

everyone's seeing the anterior and posterior.

3:00

Crus of the stapes and then the

3:02

incudostapedial joint here,

3:05

but just a conglomerate,

3:09

fused malleus and incus short process

3:13

secondary to the cholesteatoma,

3:15

which is also seen in the mastoid air cells.

3:19

In this case,

3:21

we do have an MRI scan.

3:24

What's the value of the MRI scan?

3:26

So it's been shown that diffusion-weighted imaging

3:29

is an outstanding means for distinguishing between

3:33

chronic otitis media and cholesteatoma or chronic

3:37

granulation tissue and cholesteatoma. By and large,

3:41

we say that cholesteatomas do not enhance,

3:43

or if they enhance, it's only along the periphery,

3:46

and they have restricted diffusion.

3:49

On our DWI sequences,

3:51

contrast that with the granulation tissue,

3:53

which will show contrast enhancement,

3:55

but in general, does not show restricted diffusion.

3:59

So...

4:00

See you on this case,

4:01

what we can find. We're going to look at the

4:04

diffusion-weighted scan and we're going to look at the

4:08

post-gadolinium enhanced scan as the

4:10

most useful pulse sequences.

4:13

Let's move to the diffusion.

4:15

Here we are at the DWI sequences and as you can see,

4:19

on the DWI sequence, even though there is an element

4:23

of motion artifact, we have bright signal intensity

4:28

associated with the mastoid air cells on the

4:32

left side where we had that big cavity.

4:35

So that bright signal intensity.

4:37

We want to verify on the ADC map that

4:41

it represents low signal intensity.

4:45

What we're seeing is the low signal

4:47

intensity of the cholesteatoma.

4:51

This is all bright signal intensity on the ADC map.

4:56

This is the lower signal intensity on the ADC map.

4:59

Representing the cholesteatoma.

5:02

Let's look at it on post-gadolinium enhanced scans.

5:06

Here on the gadolinium-enhanced sequences,

5:10

we note the absence of enhancement

5:15

in that collection.

5:18

Even around the periphery,

5:19

there's just a little bit of contrast enhancement

5:21

within the cholesteatoma that's

5:24

in the mastoid air cells.

5:26

The other stuff that's showing contrast enhancement

5:28

is just inflammatory cells. You want to, again,

5:31

look at the pre-GAD and post-GAD so that way you can

5:34

compare how much of this is enhancement

5:36

versus not.