0:01

I'd like to show a few cases of disease in the epidural

0:04

space which is unassociated with the vertebral bodies and

0:10

yet still is likely to cause compression of the spinal cord.

0:14

And I'm going to show a series of cases here.

0:17

This is a patient who has these low signal intensity areas

0:21

in the epidural fat, compressing the spinal cord anteriorly.

0:25

We notice that these low signal intensity areas on

0:28

T2-weighted scanning are the same signal intensity

0:31

as the bone marrow. This is an additional case.

0:35

This patient has had a post myelogram CT performed, and we see

0:42

that there is soft tissue in the posterior epidural space,

0:47

which is compressing the thecal sac anteriorly.

0:50

We notice that the bones don't look particularly good here,

0:53

this sort of osteopenic anemic-looking bones.

0:57

And even in the lumbar region,

0:59

we do have areas of abnormal signal intensity in the

1:03

anterior epidural space associated with the sacrum.

1:07

Both of these cases were patients who had

1:10

extramedullary hematopoiesis, that is,

1:12

red marrow cells effectively in the epidural space,

1:16

which can lead to compression of the spinal cord.

1:19

We see that this is epidural on the axial CT

1:22

scan, post myelogram, the cord, the thecal sac,

1:26

and then in the epidural space, the soft tissue.

1:29

Here is another case of extramedullary hematopoiesis.

1:33

In this case, we see that there is high signal intensity

1:37

on post-contrast imaging in the soft tissue on either side of

1:42

the spinal cord in the epidural space,

1:44

and that also is typical of active marrow in the epidural space.

1:50

And this has led to compression of the thecal sac in a

1:54

polygonal pattern that has been described as

1:58

a sign of extramedullary hematopoiesis.