0:00

Although the nomenclature committee emphasized

0:04

the lumbar spine for the description

0:06

of disc herniations,

0:09

it can be applied to the cervical spine as well.

0:12

And so we do use the same terminology.

0:15

The difference in the cervical spine is that we

0:18

have more commonly found osteophytes, as well as

0:23

uncovertebral joint degenerative changes

0:26

in the form of spurring.

0:28

I use the term uncovertebral joint,

0:31

some people use the term Luschka joints.

0:34

However, these are the joints that will affect the

0:37

neural foramina from an anterior lateral location.

0:42

On this case,

0:43

I'm going to be emphasizing the value

0:46

of the gradient echo scan.

0:48

Here we have a sagittal T2-weighted scan in which

0:51

we can see that the patient has multilevel

0:54

disease, predominantly at the C4-C5 level,

0:56

but also at the C6-C7 level.

0:58

At the C6-C7 level,

1:00

we do see high signal intensity within the spinal

1:03

cord and we see a disc herniation, which is

1:06

extending quite largely down past

1:10

the C7-T1 level.

1:12

So this is a large disc herniation compressing

1:16

the spinal cord. However,

1:17

I want to go level by level to see the difference

1:21

between what one sees on a gradient echo scan

1:24

versus a fast spin echo T2-weighted scan.

1:28

So let's go all the way up to the top.

1:30

So here we are at the C1 level and we're

1:34

cutting just through the odontoid process.

1:37

In the middle is the gradient echo scan and

1:40

to the right is the T2-weighted scan.

1:43

One of the values of the gradient echo scan,

1:45

which I emphasized on my intradural intramedullary talk,

1:50

was the ability to see the spinal cord

1:53

gray matter and white matter,

1:55

with the central gray matter being evident

1:57

here on this gradient echo scan.

2:02

And this also allows us a nice way of

2:05

identifying demyelinating plaques.

2:08

Sometimes it's better than the fast spin echo

2:11

T2-weighted scan.

2:12

As we go through the first level,

2:14

and for this, I'm going to put our little marker here

2:19

of where we are in the spinal canal.

2:23

So on the scan through the disc,

2:27

you notice that the disc material is

2:29

bright on a gradient echo scan,

2:32

whereas on the T2-weighted scan through

2:35

the exact same location, it's dark.

2:37

This is the problem with fast spin echo T2-weighted

2:40

scanning in the cervical spine, in that both

2:43

the disc material as well as the bone or

2:47

osteophytes are going to be both dark.

2:50

So in this situation,

2:52

I see the bright signal intensity

2:54

disc and the dark bone edge,

2:57

whereas here on the T2-weighted scan,

2:59

I really can't make that distinction very well because

3:02

they're both going to be dark.

3:04

So this C2-C3 level, we would pass.

3:07

We'll continue down to the C3-C4 level.

3:11

Again, nice demonstration of the disc.

3:14

Here we have the Luschka joint and the posterior

3:19

margin of the annulus. Everything looks good.

3:22

Note that everything's dark on the fast spin echo

3:25

T2-weighted scan.

3:26

The neural foramina look wonderful.

3:28

Again, nice demonstration of the spinal cord and the gray

3:33

matter centrally, and the white matter tracts

3:35

around it. We continue down to the next level.

3:38

And here we are at the C4-C5 level.

3:41

I'm going to brighten this, if I may,

3:45

on the T2-weighted scan

3:50

to emphasize that even with changing the windowing

3:54

what we see here is something that's dark,

3:57

indenting the thecal sac.

3:59

Is this disc material or is this osteophyte?

4:02

Right now, on our fast spin echo scan,

4:05

we can't tell the difference.

4:06

And this is why some people resort to using the

4:09

term "disc osteophyte complex"

4:12

because they're both dark. However,

4:14

we do have that ability on the gradient echo scan

4:17

to demonstrate that the predominant abnormality

4:19

here is high in signal intensity to the right

4:23

of midline representing disc herniation,

4:26

not osteophyte.

4:27

This little dark signal intensity here is the

4:30

posterior ligamentous complex with a posterior

4:33

longitudinal ligament, not an osteophyte.

4:37

Here's the Luschka joint looking fine.

4:39

The neural foramina looking fine.

4:40

Let's go down to the next level.

4:44

So next level here is at C5-C6.

4:48

Once again, what I'm seeing is predominantly bright

4:51

signal intensity on our gradient echo scan

4:54

and therefore disc material.

4:56

There may be a small component of osteophyte as

5:00

this dark signal intensity,

5:02

as opposed to the ligamentous complex.

5:04

Here on the T2-weighted scan, not very helpful.

5:07

In each of these, we're also describing whether or not

5:11

it is non-compressive disc herniation

5:13

or whether it's abutting on the spinal cord,

5:16

or whether it's compressing the spinal cord.

5:19

The nerve roots are not as well demonstrated on

5:23

the cervical spine as we have

5:24

seen in the lumbar spine.

5:28

This would be a small disc herniation because it

5:31

only represents less than one-third of the spinal

5:33

canal width. So it'd be just mild, if you will,

5:37

spinal canal stenosis.

5:39

Let's go down to that bad boy down here.

5:42

And now we are at the C6-C7 level where we see that

5:45

we have on the sagittal scan

5:46

this large disc herniation.

5:48

So this disc herniation is seen to the left of

5:51

midline going from a parasagittal location

5:55

into the lateral recess.

5:56

We know that we're at the lateral recess

5:58

because we have the pedicle here,

6:00

and here, and you see that the spinal cord is being

6:04

displaced and compressed by the large disc herniation.

6:09

This is also nicely seen on the T2-weighted scan.

6:13

This material is bright in signal intensity,

6:15

identifying it as disc material and not osteophyte

6:19

or ossification of the posterior longitudinal ligament.

6:22

We continue further inferiorly.

6:25

We see the disc material,

6:27

the spinal cord being displaced to the right side

6:31

and the disc material at the level

6:33

of the lateral recess.

6:36

We can see a little bit better the distinction

6:39

between the spinal cord and the disc herniation.

6:42

And this disc herniation has a more distal portion

6:46

that's wider than the portion

6:48

attached to the parent disc.

6:49

You can see that from this point across here

6:52

versus where it's attached to the parent disc.

6:56

And that is therefore an extrusion.

7:02

And as I said,

7:03

this disc herniation goes all the way down to

7:05

past the 2, 3, 4, 5, 6, 7,

7:10

7-1 level on the left side.

7:17

So to summarize,

7:21

very large disc herniation compressing the spinal

7:24

cord from the C6-C7 level, migrating inferiorly

7:28

to the C7-T1 level to the left of midline

7:32

with a disc extrusion.

7:37

And the other thing to emphasize is the value of

7:40

the gradient echo scan, as opposed to fast spin

7:43

echo Tw-weighted scanning,

7:44

where disc and osteophyte often are harder to distinguish.