0:00

Here's a patient

0:02

where the axial T two weight image looks like a distended,

0:06

but otherwise unremarkable fourth ventricle.

0:08

That all just looks like CSF,

0:11

although it looks a little bit large.

0:13

And, but if we look at this balanced,

0:16

steady state precession technique,

0:18

there's actually a solid lesion in there.

0:20

Just that solid lesion just happened to be

0:23

very bright on T two weight imaging.

0:27

And on a DC maps, we see facilitated diffusion 1550,

0:32

uh, d uh, for the diffusivity, there's some mild areas

0:37

of post contrast enhancement along the periphery.

0:41

It's relatively hypo dense on ct

0:44

and so, so far it's looking like a pilocytic astrocytoma,

0:48

but it looks like it's within the fourth ventricle, which is

0:52

not where we'd normally think of a pilocytic astrocytoma.

0:55

Well, if we go up a little bit higher,

0:57

there's either thickening and,

0:59

and involvement of the right superior cerebral peduncle.

1:04

So it's, this is a possible site of origin of a lesion

1:07

that's exophytic into the fourth ventricle.

1:10

So intraoperative MR.

1:12

Demonstrated gross total resection

1:13

of the fourth ventricular component of the lesion.

1:17

Um, and again, that high water content.

1:21

Um, earlier I talked with me Neoblastoma,

1:24

how the high gro cytoplasmic ratio corresponded

1:28

with the darker appearance on T two, which corresponded

1:31

with the brighter appearance on ct.

1:33

For this one, I'll say the,

1:35

the hyperintensity appearance on T two goes

1:38

with a high water content for this low grade tumor,

1:41

but that also for the surgeon implies it's very likely

1:45

that it's going to be very soft and suckable.

1:47

And it's, it was true that it, um, this was able to be,

1:53

um, the intraventricular portions of the tumor were able

1:56

to be sucked out, uh, with relative vs.

Case: Pilocytic Astrocytoma Within the Fourth Ventricle

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0:00

Here's a patient

0:02

where the axial T two weight image looks like a distended,

0:06

but otherwise unremarkable fourth ventricle.

0:08

That all just looks like CSF,

0:11

although it looks a little bit large.

0:13

And, but if we look at this balanced,

0:16

steady state precession technique,

0:18

there's actually a solid lesion in there.

0:20

Just that solid lesion just happened to be

0:23

very bright on T two weight imaging.

0:27

And on a DC maps, we see facilitated diffusion 1550,

0:32

uh, d uh, for the diffusivity, there's some mild areas

0:37

of post contrast enhancement along the periphery.

0:41

It's relatively hypo dense on ct

0:44

and so, so far it's looking like a pilocytic astrocytoma,

0:48

but it looks like it's within the fourth ventricle, which is

0:52

not where we'd normally think of a pilocytic astrocytoma.

0:55

Well, if we go up a little bit higher,

0:57

there's either thickening and,

0:59

and involvement of the right superior cerebral peduncle.

1:04

So it's, this is a possible site of origin of a lesion

1:07

that's exophytic into the fourth ventricle.

1:10

So intraoperative MR.

1:12

Demonstrated gross total resection

1:13

of the fourth ventricular component of the lesion.

1:17

Um, and again, that high water content.

1:21

Um, earlier I talked with me Neoblastoma,

1:24

how the high gro cytoplasmic ratio corresponded

1:28

with the darker appearance on T two, which corresponded

1:31

with the brighter appearance on ct.

1:33

For this one, I'll say the,

1:35

the hyperintensity appearance on T two goes

1:38

with a high water content for this low grade tumor,

1:41

but that also for the surgeon implies it's very likely

1:45

that it's going to be very soft and suckable.

1:47

And it's, it was true that it, um, this was able to be,

1:53

um, the intraventricular portions of the tumor were able

1:56

to be sucked out, uh, with relative vs.

Report

Faculty

Asim F Choudhri, MD

Chief, Pediatric Neuroradiology

Le Bonheur Children's Hospital

Lesson

Introduction

Lesson

Meningiomas

Lesson

Non-glial Tumors

Lesson

2021 WHO CNS Tumor Classification

Lesson

Gliomas

Lesson

Pediatric Brain Tumor Cases

Case: Pilocytic Astrocytoma Within the Fourth Ventricle