0:00

I think this is an informative case.

0:03

I'm gonna scroll through the T2-weighted

0:05

scan and ask you to identify the

0:09

mucocele on this patient's sinonasal MRI.

0:14

So here we scroll through, and somewhere

0:17

in here, we're gonna find a mucocele.

0:20

Now we know that the most common locations are in the

0:23

frontal ethmoidal region, but those look pretty good.

0:27

The maxillary sinus is an unusual

0:29

location for a mucocele.

0:31

Maybe some of you might wonder about the sphenoid sinus.

0:35

Well, this is the potential pitfall of MRI.

0:40

Let me show you the T1-weighted scan.

0:44

Wow.

0:45

So here we have a sphenoid sinus, which is completely

0:48

opacified with secretions that are slightly hyperintense

0:53

on the T1-weighted scan and completely black

0:56

on the T2-weighted scan, making it

0:59

look like it was an aerated sinus.

1:01

So compare this on the T2-weighted with this on the

1:05

T1-weighted, and you can see how MRI has that potential

1:10

pitfall where secretions may look as black as aeration.

1:14

The rest of the paranasal sinuses

1:15

are indeed normally aerated.

1:18

This expanded sphenoid sinus with

1:22

hyperproteinaceous secretions

1:24

is a sphenoid sinus mucocele.

1:27

Again, not a common location for a

1:30

mucocele, but one which we have to consider,

1:33

and one which has the complications of

1:35

potential involvement of the cavernous sinus.

1:37

It may encroach on the optic canal.

1:40

Here's where the optic nerve is gonna be coming

1:43

through, and here's our sphenoid sinus mucocele.