0:00

Dr. Schupack,

0:01

let's look at some anatomy in the coronal projection.

0:03

And I know the sphenoid sinus is

0:05

of great importance to you.

0:06

So I'll turn to you in a moment to talk about the septum

0:08

and the shape of the sinus and its surgical approach

0:11

to the gland. But here's the gland.

0:13

And for those of you that are watching, look where we are.

0:15

We're in the very anterior portion of the gland.

0:18

We said in one of our other vignettes that there was a

0:20

little bump right here. And you can see that bump,

0:23

the pars tuberalis of the pituitary gland.

0:26

Here's the pars distalis,

0:28

or the anterior portion of the pituitary

0:31

gland known as the pars distalis.

0:33

And then as we get a little further back,

0:34

we'll run into the pars intermedia,

0:36

all part of the anterior pituitary gland.

0:39

So don't confuse this upward convexity bump

0:42

of the pars tuberalis for an adenoma.

0:45

Now,

0:46

sometimes you can have normal upward convexity,

0:49

especially in somebody who's in puberty or somebody

0:52

who's pregnant. So that in itself,

0:54

especially when midline and even eccentrically

0:56

all by itself is not a firm indication.

1:00

Or a hardline indication of an adenoma.

1:02

We look at the gland on either side.

1:04

There's going to be a little bit of asymmetry

1:06

with contrast enhancement.

1:08

Sometimes one side of the gland will be a little

1:10

darker than the other. It's a Ditzel,

1:12

but it's not displacing or effacing

1:15

the vascular pituitary tuft.

1:18

And then on either side, we've got the

1:20

flow void of the carotid arteries.

1:21

On this T2 coronal image, we've got the cavernous

1:24

sinuses with a lateral cavernous sinus wall which we

1:28

like to see as a dark line, not as an interface.

1:31

If it's an interface,

1:32

that means there's something infiltrating

1:34

the cavernous sinuses.

1:36

And later we're going to talk about the individual cranial

1:38

nerves like this third nerve that's filling the cavernous

1:41

sinus. Then above the pituitary gland anteriorly,

1:45

we see the optic chiasm.

1:47

And if we keep going forward, we'll follow the

1:49

optic apparatus into the optic foramen.

1:53

So now let's go backwards a little bit.

1:55

We've got no contrast on board, and now we'll

1:57

have contrast on board, and we're right.

2:00

Smack dab in the middle of the pars distalis.

2:02

We got a little motion artifact

2:04

right here due to pulsation.

2:06

But there's the pituitary tuft and you're seeing

2:08

enhancement on either side as it drifts into the cavernous

2:12

sinus region. And now you're seeing the pituitary stalk,

2:15

which is a little chubbier superiorly.

2:18

And you're also seeing the optic apparatus split as the

2:21

optic chiasm. Now as we go a little more posteriorly,

2:25

which we're going to do more contrast is coming in, little

2:28

chubbier appearance of the pituitary stalk before we move.

2:31

Slices follow along in the Sagittal projection as we move

2:34

backwards. Here we go to the next posterior cut.

2:38

And now we're in the posterior pituitary gland.

2:41

You can see just how chubby the infundibulum looks because

2:45

now you're getting into the median eminence.

2:47

So it's a little fatter.

2:48

And the median eminence is part of the posterior

2:51

pituitary gland along with the pars nervosa.

2:55

And then we've got secretory areas in the anterior

2:58

pituitary gland. If we come back this.

3:00

Where a lot of the secretory action happens

3:02

hormonally in the back of the gland.

3:04

The secretory action consists of antidiuretic

3:07

hormone and oxytocin.

3:10

We'll talk more about the coronal projection in a moment,

3:12

but I want to turn to you and ask you

3:14

about the sphenoid sinus. Right.

3:16

So a lot of the focus that clinicians are going to have is

3:20

we're interested in finding a lesion, describing it,

3:22

what it is.

3:23

They have a further question which is

3:26

can I get there and what can I do about it?

3:28

And so if you're familiar with

3:30

the transphenoidal approach,

3:32

which you need to be if you're going to read Cella,

3:35

you got to know what's going on with the sphenoid.

3:37

For example, this is an aerated sphenoid.

3:39

So here's your sella.

3:41

So you could take a transphenoidal approach here.

3:44

Now, if the sella is non-aerated,

3:47

that may preclude a transphenoidal approach.

3:50

That's something the clinician is going to be

3:51

really interested in. Now, another thing,

3:54

and we're going to illustrate this a little bit more

3:56

later, is the carotid artery is a very important structure.

4:00

Right, sella right there.

4:02

So all of these relations are very important.

4:04

So this distance, can you get to the sella this way?

4:09

Okay.

4:09

So you look this way to see is there an approach

4:12

to the sella from transphenoidally,

4:14

and also is there enough room to work in?

4:16

And that's going to be important.

4:17

You mean from side to side?

4:19

Correct. Now,

4:21

the height dr.

4:22

Pomerance talked about this when I have a laminated chart

4:27

next to my desk with the height of the pituitary

4:30

at each age and sex of the patient.

4:33

Okay. Because this one could be quite normal,

4:36

upward convexity,

4:38

and this height could be normal in a particular age.

4:41

If the patient's a male who's 80 years old,

4:44

that wouldn't be normal. Sure.

4:46

So you kind of have to get sensitive to these things.

4:48

Now, once again,

4:50

one of the big indications for any pituitary

4:53

surgery is going to be mass effects.

4:54

So you got to get really familiar with what this looks

4:57

like. The optic apparatus, pressure on the optic apparatus.

5:00

Status going to be a big indication for surgery,

5:02

what the suprasellar space looks like,

5:04

and there's some other diagnoses.

5:05

So getting familiar with these relationships is important.

5:09

Does the sphenoid sinus septum position matter?

5:11

Yeah, it does.

5:13

And that's something you can report.

5:16

And the reason is it's a really

5:18

easy way to get disoriented

5:21

if you're doing a transphenoidal surgery.

5:24

If you assume that the septum is in the middle and you run

5:28

into the septum, you say, oh, I must be in the middle,

5:30

and you're not. Okay.

5:32

So that is something that the pituitary

5:33

surgeon is going to take note of,

5:36

because what happens is it's going

5:38

to lead you right to the carotid.

5:41

Can you get trapped in this air cell if you go in

5:44

the wrong side? Well, you can get lost for sure.

5:46

And so this kind of reporting that is,

5:48

where is the septum? If you see it so that they know, hey,

5:50

I see the septum,

5:51

but that doesn't mean I'm in the midline.

5:52

So any of these surgeries, in fact,

5:56

not only transphenoidal surgery,

5:58

finding the midline reorienting.

6:00

Where you are is critical.

6:02

And these days,

6:03

where there's a lot of very advanced and extensive

6:06

surgery, it's transnasal, for example,

6:08

all these clival procedures. You know,

6:10

a lot of what they're looking for is landmarks to tell

6:13

them where they are in relation to the midline.

6:15

Okay, so that is a very important finding.

6:17

Great. Let's move on.