0:00

Hopefully, I'm gonna try to do one more case and then I'll leave

0:03

a few minutes for questions just because I wanna get on to one

0:06

more case. Here's a 21 year old with headache.

0:12

And we'll get to... Here is the imaging.

0:18

Patient had a sinus CT with contrast because he also had some left

0:24

eye swelling. And here you can see there's definitely some swelling and

0:28

a little bit of proptosis of this left eye.

0:31

Maybe you can even make out a little bit of irregular shagginess along

0:36

the optic nerve and a little bit of thickening of the extraocular muscles,

0:39

but that's subtle finding. But the other features on this study,

0:45

if you go up, and this is a subtle finding, and it's hard

0:49

because when things are symmetric, it can be really difficult. But here

0:52

you can see there's a little bit of fullness and relative hypo enhancement

0:56

in the region of the cavernous sinus. It's actually a bilateral finding.

0:59

It's on the left and the right. But see how you can see

1:02

there's a little bit of convexity to the cavernous sinus? That is an abnormal.

1:08

And then when you come up, here is the superior ophthalmic vein on

1:12

the right. And we just don't see the superior ophthalmic vein on this

1:17

left side. So a little bit unusual, so this patient went and got

1:22

an MRI. Here on the T1 weighted images, again, you see

1:27

loss of the normal fat in the orbit, some stranding around the superior

1:33

ophthalmic vein, and some preseptal soft tissue swelling, a little bit of

1:37

proptosis, a little bit of thickening. And then when you come over here

1:41

into the cavernous sinus, you really don't see much in the cavernous on

1:44

the T1 weighted pre. It's a little full, but it's hard to appreciate.

1:48

But here on the post contrast images, similar

1:52

to the CT images, again, you can see this

1:57

relative non central enhancement, but peripheral enhancement around the

2:01

expected location of the superior ophthalmic vein. And then this thickening

2:06

of the extraocular muscles, some definite postseptal inflammatory changes,

2:11

retrobulbar inflammation within the orbit, and enhancement along the optic

2:17

nerve sheath, as well as fullness and just essential non enhancement of

2:22

the left greater than right cavernous sinus. Then you have quite a bit

2:25

of sinus disease in the adjacent sphenoid sinuses as well.

2:29

So definitely a trans spatial process. And then

2:34

I can show the T2s and the diffusion images. Here on the T2

2:39

weighted images, you can see, again, some inflammation in the left orbit.

2:45

But here again, on the T2 weighted images of the cavernous sinus,

2:49

there's really just some abnormal T2 hypointense soft tissue. Typically,

2:55

the cavernous sinus should be bright on T2 weighted images and not

2:59

full and dark like that. Then on the diffusion images,

3:04

you can see a little bit of abnormal

3:07

diffusion restriction inside that left greater than right cavernous sinus.

3:11

Okay. So let's get back to the PowerPoint briefly and quickly.

3:19

Salient imaging findings, I think we've gone through it, preseptal and postseptal

3:23

inflammatory changes, non enhancement of the superior ophthalmic vein and

3:27

fullness of the cavernous sinus, adjacent sinus disease,

3:31

again, seen on the MR. What's the most likely diagnosis? Is this cavernous

3:37

sinus thrombosis, CC fistula, superior ophthalmic vein varix, or a normal

3:42

variant? Okay, let's see the answers. Okay, good. Alright.

3:56

This is a do not miss scenario, and unfortunately, this patient had a

3:59

little bit more subtle findings when they first came in.

4:02

And this was not picked up. The patient came to the ER three

4:05

times in the span of four days and

4:08

finally got contrast enhanced imaging and the diagnosis was made.

4:15

But this is cavernous sinus thrombosis. Again, this is a complication often

4:21

of sinusitis or some orbit or mid face infection. But you can also

4:25

have bland thrombus from just being hypercoagulable. Typically, patients

4:30

present with headache and a cavernous sinus syndrome, which is a painful

4:34

ophthalmoplegia, which is painful limited eye movement. They often will

4:38

have proptosis and chemosis as in this patient, so injected red eye

4:43

with limited movements. Either you are asking him to look up and he

4:46

can't move his eye. Often associated with vision loss and optic nerve deficits,

4:51

as well as other cranial nerve deficits like V1 and V2

4:55

because they extend through the cavernous sinus. So they'll also have facial

4:58

pain and V1 and V2 numbness. It's associated with a very high morbidity

5:05

and mortality. On this patient, again, we see this convex border of the

5:11

cavernous sinus. It's really important to scrutinize the cavernous sinus

5:14

on every single case. It should be concave and uniformly enhancing.

5:19

You can see here on this patient, it's concave and uniformly enhancing.

5:24

If it bows outward and is convex, even bilaterally, you want to look

5:28

for secondary inflammatory findings in the orbit with inflammation and proptosis.

5:35

And you wanna look for adjacent sinus disease.

5:39

Always, if I see it and I don't understand why, sometimes you can

5:42

have a cavernous sinus meningioma. If you see a bowed out convex cavernous

5:47

sinus, recommend that they correlate with any symptoms referable to the

5:51

cavernous sinus. And then also if you're just doing a CT,

5:54

you wanna consider an MRI with and without contrast for further evaluation,

5:58

or sometimes a CTV or MRV can be helpful.

6:04

And this is just one final word of warning. You don't always see

6:06

a filling defect in cavernous sinus thrombosis if the patient is actively

6:10

infected. It can be thrombophlebitis and the schmutz y thrombus can actually

6:16

enhance. This is a case of thrombophlebitis of the cavernous sinus,

6:20

where all you see is fullness, but it's all enhancing. Sp you wouldn't

6:24

think it was thrombosis. But here on the T2 weighted images,

6:27

you can see all this soft tissue in here. Patient has really bad

6:30

sinus disease and this was a patient with cavernous sinus thrombophlebitis.

6:34

So you wanna really make sure that you look at all of your

6:36

sequences at the cavernous sinus. You wanna look on your T2s, you look

6:40

at your T1s, look at your diffusions, and your post contrast images,

6:44

and then looking for secondary findings in the orbit. Just briefly,

6:49

a differential for this enlarged superior ophthalmic vein and proptosis

6:53

is a cavernous sinus fistula, a CC fistula, which is an AV... Direct

6:58

fistulas are a high flow and post traumatic, often from skull based fractures

7:02

or an aneurysm rupture, or an indirect dural AV fistula.

7:08

Similar to our case, they typically see proptosis of the ipsilateral eye

7:12

with preseptal and postseptal fat stranding and enlargement of the extraocular

7:15

muscles. But in these cases, instead of thrombosis and non filling of the

7:20

ophthalmic veins, you'll see actually enlargement of the ipsilateral superior

7:24

and inferior orbital veins as in this patient. Here is a case,

7:29

you see again, asymmetric enlargement of the ipsilateral superior ophthalmic

7:33

veins, and flow voids on the ipsilateral side. This is a patient with

7:39

a big superior ophthalmic vein, some flow voids and asymmetric filling and

7:44

convexity of that cavernous sinus. MRA, particularly time resolved MRA,

7:50

can be suggestive as in this case, showing early filling of the right

7:53

cavernous sinus, which then drains into the superior ophthalmic vein. But

7:57

digital subtraction angiography is actually the gold standard for diagnosis

8:00

and also used for treatment planning prior to transvenous and/or transarterial

8:05

embolization. And so here's the early filling on the arterial injection

8:09

of the cavernous sinus coming out into the superior ophthalmic vein. And

8:13

then finally, orbital varix, you can also have an isolated enlarged superior

8:16

ophthalmic vein and sometimes proptosis. You wanna look... Make sure the

8:21

cavernous sinus looks symmetric in these patients. Then sometimes you can

8:24

confirm an orbital varix by having the patient Valsalva during imaging and

8:29

these will enlarge. Okay. I think we're going to stop there in the

8:33

interest of time. I had a couple more cases, but now I know

8:37

how much I ramble. I can show these again in the future.

8:43

I have a few minutes for questions. I can stay after as well.

8:46

I'm gonna stop sharing. Let's see. Let's go to the Q&A. I see

8:51

a couple of questions. Okay. Does a vagal paraganglioma always displace

8:55

the ICA anteriorly? Can it be displaced posteriorly? I have never seen it

9:00

displaced posteriorly. It lives in between the two vessels and the ICA lives

9:05

medially. And I think because of where the carotid is and the prevertebral

9:10

musculature behind, it just takes the path of least resistance and gets

9:13

pushed forward. It may be pushed a little bit more medially, but it's

9:17

always anteriorly or anteriorly medially. I've never seen it posteriorly

9:23

displaced, for a vagal paraganglioma. That being said,

9:30

there are some other nerve sheath tumors that can push the ICA posteriorly,

9:35

but we won't go into that. Can cavernous sinus thrombosis ever be suggested

9:39

on non contrast head CT? Yes, in my opinion, you can if you

9:44

have some periorbital inflammatory change and asymmetric fullness of that

9:49

cavernous sinus. Absolutely. And what's really helpful though, is these

9:54

patients are almost uniformly gonna be very symptomatic. So if you can get

9:57

a hold of a clinician and ask them,

10:01

they're gonna have a cavernous sinus syndrome if they have cavernous sinus

10:04

thrombosis. They're gonna have a headache. They're gonna have painful and

10:08

limited eye movements. They're gonna have facial pain with V1 and V2

10:13

pain and numbness. And those findings progress over time pretty rapidly

10:18

though. And so those patients are really, really sick, usually, and really

10:22

symptomatic. So that can also help if you're questioning it, just to pick

10:26

up the phone and call. Okay I think those are the only questions

10:32

I have. If anyone else has anything else, I'd be happy to entertain

10:36

them. Thank you.