0:01

This is the quandary that we sometimes have

0:03

with evaluation for patients who have vascular

0:06

malformations of the spinal canal.

0:09

This is a patient who had

0:10

a thoracic myelopathy.

0:12

As we scroll the images on T2-weighted scans,

0:16

we see what appears to be prominent vessels on

0:19

the surface of the spinal cord, which are

0:21

selective in the lower thoracic region.

0:24

We don't see them going superiorly

0:27

above the T6 level.

0:29

This is present both on the STIR image, as well

0:32

as on the traditional spin echo T2-weighted scan.

0:37

Lots of prominent vessels in the intradural

0:39

extramedullary space.

0:41

Well, it is said that patients who have vascular

0:45

malformations, like a dural AV fistula,

0:48

if they're symptomatic,

0:50

they almost always will have abnormal

0:52

signal intensity in the spinal cord.

0:54

In this case,

0:55

both on the STIR and the T2-weighted scan,

0:58

the spinal cord signal is normal.

1:00

So what will we do?

1:01

Is this a vascular malformation that just

1:04

hasn't gotten to the level of venous

1:05

congestion that the cord is bright?

1:08

Or is this normal variation blood vessels

1:11

on the surface of the spinal cord?

1:13

In this situation,

1:13

we would obtain postgadolinium-enhanced scans

1:17

and in this particular patient,

1:20

that was not performed.

1:22

But the patient did go on to spinal arteriography

1:25

and it was normal.

1:27

So again,

1:28

the adage is that if it is a symptomatic

1:31

spinal dural AV fistula,

1:33

you should see abnormal signal intensity

1:35

within the spinal cord.

1:37

And if you don't see abnormal

1:39

signal in the spinal cord,

1:40

then I would be a little bit more cautious

1:43

about calling it a vascular malformation.

1:46

So again, word to the wise,

1:48

do the postgadolinium-enhanced

1:49

scans. And also, if that is equivocal,

1:54

try your spinal arterioven...

1:56

uh, your spinal angiogram.

1:57

Your dynamic injection of contrast

2:00

for a spinal angiogram.

2:01

So, what's the difference between this case

2:04

and the previous example I demonstrated?

2:07

Here we have a patient that also

2:09

has a thoracic myelopathy.

2:10

The patient is 69 years old.

2:13

And we again see what appear to be a lot of

2:16

prominent squiggles on the surface

2:18

of the spinal cord.

2:19

You'll notice that they are predominantly

2:21

on the posterior aspect,

2:22

although more anteriorly here.

2:24

And there is also associated cord signal abnormality.

2:29

So here is the demonstration of the intradural

2:32

intramedullary cord signal abnormality, in

2:36

associated with prominent vessels in the

2:40

intradural extramedullary location

2:43

that are present on STIR imaging.

2:47

Little squiggles. As well as post contrast imaging

2:53

where we see them as little dots of contrast enhancement

2:56

in the intradural extramedullary compartment.

3:00

So the difference between this case and the

3:02

previous case is that the vascular abnormality that we see,

3:06

or the blood vessels, are extending all the way

3:09

up to the cervical region and down

3:12

to the lower thoracic region.

3:15

It is associated with abnormal cord

3:17

signal abnormality. And in fact,

3:20

on the post gadolinium-enhanced scans,

3:23

we see that there is is kind of a faint

3:26

enhancement of the cord itself.

3:28

This is secondary to that venous congestion

3:31

that I mentioned previously.

3:32

I'm just going to magnify that and compare it

3:36

to the pre gadolinium T1-weighted

3:38

images where, again,

3:40

you see that there is that faint enhancement

3:44

in the conus medullaris.

3:47

So this is a patient who had a dural

3:50

arteriovenous fistula.

3:51

Type 1 spetzler classification,

3:54

associated with abnormal cord

3:56

signal myelopathy, as well as draining

4:00

veins in the intradural extramedullary

4:02

compartment and cord signal abnormality,

4:05

intradural intramedullary. So, again,

4:08

this is a patient that gets referred

4:10

to conventional arteriography,

4:11

at least at my institution.