0:00

We're back with our 22-year-old, young woman.

0:04

We've got a beautiful, beautifully performed,

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dynamic contrast enhanced MRI,

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You can see, here is the pre.

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And then immediately,

0:11

the lesion enhanced has got some cystic foci.

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This is a coronal T1.

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Sagittal T2-weighted fast spin-echo.

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Coronal T2 fast spin-echo with a little scrolling.

0:20

Clearly, there is a sellar mass with suprasellar extension.

0:24

So, we talked about some of the approaches

0:27

to evaluating this lesion.

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Is there blood in it?

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Is there fat in it?

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Is there calcium in it?

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Are there cysts in it?

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And this affects the differential diagnosis.

0:35

You know, you've got cyst,

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you start thinking craniopharyngioma

0:38

or big macroadenoma.

0:40

You've got calcium,

0:41

you start thinking meningioma, craniopharyngioma.

0:44

You got fat in it,

0:45

you start thinking about lipoma or certain

0:47

types of proteinaceous material.

0:49

In fact, you may be thinking about dermoid.

0:52

You got blood in it,

0:53

you think about a big hemorrhagic

0:54

adenoma pituitary apoplexy.

0:57

Another question you should ask yourself,

0:58

"Is the patient an adult or child?"

1:01

If it's a child,

1:02

you're thinking about things like anorexia nervosa

1:04

and pituitary hyperplasia,

1:05

never be this big.

1:07

Hydrocephalus with prolapse of the

1:09

ventricles down in a child.

1:10

Pilocytic astrocytoma.

1:13

Craniopharyngioma.

1:14

In an adult, you're thinking mostly pituitary adenoma,

1:18

and maybe meningioma.

1:20

Another key question,

1:21

"Is the lesion intra or extra-axial?"

1:25

If it's extra-axial,

1:26

does it arise from the pituitary gland like this one does?

1:30

Or can you identify a separate pituitary gland

1:34

from the mass?

1:35

So you might say,

1:36

"Okay, let's look real carefully in here.

1:38

Do I see either a J-shaped structure like this

1:42

or a U-shaped structure like this,

1:44

that is separated from our lesion?"

1:46

And the answer is no, we do not.

1:49

Is it an intra-axial mass?

1:51

You know,

1:51

does it arise from the optic chiasm or the hypothalamus?

1:54

Let's scroll the sagittal.

1:56

I mean, where is the hypothalamus?

1:57

The hypothalamus is right over here.

2:00

Let me take my pen and mark it for you.

2:01

Right over there.

2:03

The optic chiasm?

2:04

Well, who knows?

2:05

It's squished.

2:06

As I'll get out, I can hardly see it.

2:09

What's the status of the third ventricle?

2:11

Let's have a look in the sagittal projection.

2:13

Did this thing comes from the third ventricle?

2:14

We'll, no, it didn't.

2:16

It's effacing the third ventricle.

2:18

It's displacing the third ventricle.

2:20

As we said,

2:20

is it cystic or solid?

2:22

But let's take that one step further.

2:24

If it's cystic,

2:25

does it have the characteristics of cerebrospinal fluid,

2:29

you need a true T1, a FLAIR and a T2 to tell that.

2:33

Because on one,

2:34

it may look like CSF.

2:35

On others, it may not.

2:37

An example of a cystic lesion.

2:39

A "cystic lesion" would be an epidermoid

2:42

but it doesn't match the cerebrospinal fluid.

2:45

So go ahead and drill a little bit deeper to try

2:49

and decide the exact character of the fat.

2:52

Is it simple fat or is it complex fat?

2:55

Is it acute blood? Or is it chronic blood?

2:58

Is it chunky calcium?

2:59

or is it stippled calcium?

3:01

Which you might see in a meningioma.

3:03

And is the CSF...

3:05

Is the cystic part true CSF

3:07

or is it a macerator of CSF?

3:10

And when you look at all the sequences,

3:12

it's really not a direct match for CSF.

3:15

That's the approach to dealing with suprasellar lesions.

3:18

Ready to move on?

3:20

Yes.

3:20

Let's do it.