0:01

Most of the time, when you're scanning

0:03

patients in the trauma setting,

0:05

it's usually for ligamentous injury associated

0:08

with cervical spine trauma with motor vehicle

0:11

collisions, and this may be in association with

0:16

fractures that are identified on the

0:18

CT scan of the cervical spine.

0:21

Occasionally, however,

0:22

you will see injuries to the spinal cord

0:25

associated with those traumatic events.

0:28

When that occurs, it mat be traumatic...

0:31

it may be hemorrhagic or non-hemorrhagic injury.

0:35

The prognosis of a patient who has a hemorrhagic

0:39

injury to the spinal cord from trauma is far

0:42

worse than those who have non-hemorrhagic stretch or

0:48

compression injuries to the spinal cord.

0:51

When you have hemorrhage in the spinal cord,

0:54

you may use the term hematomyelia—blood in the

0:57

cord—and occasionally, you will have complete

1:02

cord transection in those patients who have

1:05

fractured dislocation of the spinal

1:07

cord...

1:08

of the spinal canal.

1:10

The hemorrhagic lesions in the spinal cord can

1:13

lead to late complications such as development

1:17

of acquired arachnoid cyst, secondary to

1:21

adhesions from the blood products or alteration

1:25

of the CSF dynamics, leading to spinal cord searings.

1:30

So it is important to perform gradient echo

1:34

scans in the post-trauma situation where you're

1:38

looking for hemorrhagic blood products in

1:40

patients who are being evaluated

1:43

for cord injury.

1:45

Here is a patient who had a traumatic injury

1:48

in the thoracic region and had a clinical

1:56

symptomatology which suggested a

1:58

transection of the spinal cord.

2:01

Although the MR images were not

2:04

suggestive of it, clinically,

2:06

they felt that the patient had cord

2:09

transection by virtue of the

2:12

bilateral Brown-Séquard clinical symptomatology.

2:16

T1-weighted scans don't look all that bad.

2:19

We don't see a lot of bright signal intensity.

2:21

Remember that in the acute phase,

2:24

deoxyhemoglobin may be iso-intense to the

2:28

cord parenchyma. On the STIR image,

2:31

a little bit of dark signal intensity.

2:33

And then on the T2-weighted scan, you see what

2:38

looks like an area where there is discontinuity

2:41

in the spinal cord with a small crescent

2:44

of hemorrhage being present here.

2:47

And this was indeed the site of the injury

2:51

to the spinal cord. In this situation,

2:54

we do not have gradient echo scans to confirm it.

2:58

Subsequent images on the axial T1-weighted scan,

3:02

you are able to see a little bit of bright signal intensity

3:05

methemoglobin in the transected cord on follow-up.

3:10

From here, I'd like to move to the vascular

3:12

lesions of the spinal canal and the

3:15

intradural intramedullary space.

3:18

So we're now at the V of vitamin C and D.

3:21

We did infectious, we did traumatic,

3:24

acquired, metabolic, idiopathic,

3:26

with the demyelination.

3:27

Neoplastic, we covered.

3:29

Congenital, we covered. And we haven't done drugs yet.

3:32

So vascular lesions.

3:34

Cavernomas are the most common

3:36

of the vascular cord lesions.

3:40

These are your cavernous hemangiomas.

3:42

They are typically seen as bright on T1 and

3:46

bright on T2 because of the presence

3:48

of extracellular methemoglobin.

3:51

Remember that intracellular methemoglobin is

3:55

bright on T1 but dark on T2, whereas

3:58

extracellular methemoglobin is bright

4:01

on T1 and bright on T2.

4:03

However, these lesions,

4:04

which are chronic lesions, often have a ring of

4:08

dark signal on T2-weighted scan from hemosiderin

4:11

around their periphery.

4:13

The cord caliber may be atrophic if there has

4:17

been recurrent hemorrhage and cord injury,

4:20

or it may be expansive if the lesion itself has not

4:26

caused cord hemorrhage but is a space-occupying

4:29

lesion. The enhancement, if it's present,

4:32

is usually mild, but enhancement is variable.

4:36

And remember that these are occult

4:38

cerebral vascular malformations.

4:40

By occult, we mean that the angiography

4:43

is usually negative.

4:44

So these lesions can cause a Brown-Séquard

4:49

syndrome or acute neurologic symptoms.

4:52

Here is a magnified view of a T2-weighted

4:54

scan, and you see the dark signal intensity

4:58

hemosiderin ring around this lesion, which is

5:00

otherwise bright on T2-weighted scanning.

5:04

Here is the dark hemosiderin ring with the

5:08

central bright signal intensity.

5:09

Now, why isn't this an ependymoma with a cap signate,

5:13

for example? Well, you'll notice that

5:15

there is no evidence of edema

5:17

above or below the lesion, which would be

5:19

decidedly unusual for a cord neoplasm.

5:23

That's sort of the expected finding with a

5:26

cavernoma of the spinal cord unless

5:28

that cavernoma has recently bled.

5:32

Here is an additional case where on the

5:35

T2-weighted scan, you see a comma-shaped area of dark

5:39

signal intensity within a spinal

5:41

cord, which is not expanded.

5:43

So this is our T2-weighted scan, and we see the

5:47

dark signal intensity of hemosiderin.

5:50

On the T1-weighted images,

5:53

we see some bright signal intensity,

5:55

that's some residual methemoglobin

5:57

associated with the lesion.

6:00

And when we compare the gradient echo scan

6:05

to the spin echo scan,

6:08

we see the blooming of the hemosiderin, the

6:12

blood products, on the gradient echo scan in

6:15

association with some replacement of

6:19

the spinal cord by the blood products.

6:21

So this is a nice example of a

6:24

cavernoma of the spinal cord.