0:01

If we look at this patient who

0:04

has a cauda equina syndrome,

0:07

we note that there are markedly enlarged nerve

0:11

roots throughout the cauda equina.

0:13

Here we have the spinal cord coming down,

0:16

which looks fine.

0:17

No abnormality in the signal intensity of the spinal

0:19

cord, but we have this thickening of the nerve roots.

0:23

This is confirmed on the axial scans through the

0:27

lumbosacral region, and the nerve roots are enlarged.

0:31

Not only that,

0:32

but we see that there are enlarged neuroforamina with

0:36

nerve roots coming out, and once again appearing to be

0:38

within the psoas muscle and then extending

0:41

into the lumbosacral plexus.

0:43

This is actually coming from the sacral neuroforamina,

0:46

which are also markedly enlarged here.

0:49

So in this case,

0:50

the patient did not have contrast ordered.

0:53

We brought the patient back later in

0:55

the day to administer contrast.

0:59

Why would we care about the contrast?

1:01

Well, certainly in our differential diagnosis of things like

1:05

subarachnoid seeding or neurofibromatosis

1:09

or an infectious etiology, sarcoidosis,

1:12

noninfectious inflammatory etiology,

1:15

we would expect to see contrast enhancement.

1:17

So the contrast enhanced study was performed.

1:21

As you can see,

1:22

this was done postgadolinium with fat suppression,

1:26

fat-suppressed on the T1-weighted scan,

1:28

and there is absolutely no enhancement of

1:30

the nerve roots here on the axial scans.

1:33

Although this is a little bit of dark,

1:35

we don't see any enhancement.

1:36

We see the enlargement of the neuroforamina and nerve

1:40

root sleeves and the nerves out into the periphery,

1:44

but none of them are enhancing.

1:45

So that effectively rules out subarachnoid seeding, neurofibromatosis,

1:50

infectious etiologies.

1:52

This was another patient who had CIDP,

1:55

and CIDP may or may not show contrast enhancement.

2:00

Be careful with CIDP because often the patients will

2:04

have at least a course of steroids for a therapy.

2:07

And if that is administered,

2:10

it may suppress the gadolinium enhancement

2:12

that may occur with CIDP.