0:01

This was a patient who have had previous surgery on the

0:04

brain and was presenting with a thoracic myelopathy.

0:09

We have the T1-weighted,

0:10

T2-weighted and post-gad T1-weighted scans showing.

0:14

In this situation, what we see is that there is indeed

0:17

abnormal signal intensity within the spinal cord

0:20

beginning at the cervical thoracic junction.

0:23

As we look further inferiorly,

0:25

we come into this bright signal intensity area on the

0:28

sagittal STIR image, which is intradural

0:32

but extramedullary, as we can see, with widening

0:35

of the subarachnoid space.

0:38

There is no evidence of contrast enhancement

0:42

associated with the abnormality.

0:45

Axial scans confirm the intradural

0:49

extramedullary location of the cysts.

0:53

We can see the fluid collection within the thecal sac

0:57

causing displacement and deformity of the spinal cord,

1:01

as well as abnormal signal intensity in the spinal cord.

1:05

This is an example of an acquired arachnoid cyst

1:10

secondary to adhesions that occurred postop from

1:14

surgery that was performed intracranially.

1:17

These cysts will not show contrast enhancement.

1:20

In fact, let's go see the post gad T1 scans through the similar

1:24

region. So you see absence of contrast enhancement.

1:27

We're a little bit too low there.

1:30

But on the scans,

1:32

you don't see enhancing areas within the spinal cord.

1:36

And this is a nice example if I magnify this one where

1:41

you can see the non-enhancing CSF signal intensity

1:46

lesion displacing the spinal cord within the thecal sac.

1:51

So, intradural extramedullary cyst compressing the spinal

1:57

cord in this kind of ball valve effect and leading

2:00

to abnormal signal intensity in the spinal cord

2:03

and a myelopathy as an acquired arachnoid cyst.