0:00

Let's look at some of the imaging of multiple

0:03

sclerosis and the plaques

0:05

that are associated with it.

0:07

So on your left-hand side,

0:09

you have something which is a

0:10

little bit anachronistic,

0:12

and that is a proton density-weighted scan.

0:14

As I mentioned,

0:16

there are multiple research programs that are

0:18

using the combination of proton density

0:20

weighted imaging and T2-weighted imaging to

0:23

do volumetric analysis of multiple

0:26

sclerosis plaques.

0:27

Because proton density-weight imaging and T

0:30

two-weighted imaging come as a dual echo

0:32

sequence, you don't show motion artifact,

0:36

which would cause a little bit of offset when

0:38

you're doing volumetric imaging. For MS.

0:40

Plaque volume.

0:42

On the proton density-weight scan,

0:44

you can see that the CSF is slightly

0:46

low in signal intensity,

0:47

but the demyelination is bright.

0:50

So by that,

0:51

I mean that this CSF space is a little bit

0:53

darker in signal intensity than the

0:56

Demyelination on a proton

0:58

density-weighted scan.

0:59

Contrast that with your flare scan

1:02

on your right-hand side,

1:03

in which case you see a very dark CSF sulcus,

1:08

but very nicely demonstrated the contrast

1:11

with the white matter lesions.

1:13

So these would be classified as

1:15

periventricular white matter disease,

1:17

and as we get close to the cortex,

1:20

we would have juxtacortical lesions on the

1:23

flare scan being demonstrated here,

1:25

this lesion is probably at the top of the

1:28

lateral ventricle and so would really be

1:30

classified more as a periventricular lesion.

1:33

So we've seen juxtacortical lesions,

1:36

and we've seen periventricular lesions.

1:38

The other areas that we include in the four

1:42

locations of the McDonald criteria are the

1:46

infratentorial space and the spine.

1:49

Within the infratentorial space,

1:51

we include those lesions that are in the brain

1:54

stem as well as those out in the

1:56

periphery of the cerebellum.

1:58

This is a lesion in the middle cerebellar

2:00

peduncle classified as infratentorial

2:03

in location. However, as I said,

2:05

it's important to look at the

2:07

periphery of the brain stem,

2:09

because quite often you see small lesions on

2:12

the surface of the brain stem that will be

2:15

classified as demyelinating plaques

2:17

fulfilling infratentorial location.

2:20

Those white matter lesions out in the

2:22

periphery of the cerebellum are better seen

2:25

on T2-weighted scan than flare scan,

2:28

and that is why we emphasize the T2-weight

2:31

scan for infratentorial evaluation.

2:35

To the right, we see spinal cord lesions.

2:38

The spinal cord lesions of multiple sclerosis

2:42

usually represent one to two segment disease.

2:47

These are not the long segment disease.

2:51

So this lesion, by segment,

2:53

we're talking about two C, three C, four,

2:56

each of these being a segment of the spine.

2:59

Notice that the white matter lesions here are

3:02

separated as smaller lesions that

3:06

span one to two segments,

3:08

not longitudinally

3:12

extensive white matter lesions.

3:16

Longitudinally extensive white matter lesions

3:18

are what we will see more commonly in

3:21

neuromyelitis optica spectrum disorder and in

3:25

idiopathic acquired transverse myelitis.

3:29

Just as in the brain.

3:31

We do the post-gad scans in the spine

3:35

to look for enhancing plaques,

3:37

and these enhancing plaques can be seen

3:40

showing peripheral enhancement or

3:43

solid contrast enhancement.

3:46

On the post-gad T1-weighted scans,

3:49

we use traditional Spin-echo

3:52

T1-weighted scans.

3:55

Some people are using Vibe scans because you

3:59

can get thinner sections. In some cases,

4:02

it may show the periphery

4:04

of the spinal cord better.

4:07

So you have your choice there between spine

4:09

echo T1-weight scans versus the

4:12

Vibe T1-weight technique.

4:14

Sagittal flare scans are critically important

4:18

because they show the white marrow

4:20

lesions very nicely,

4:23

as well as defining what I had described

4:26

previously as your colossal

4:28

septal interface lesion.

4:30

So this is at the periphery under surface

4:33

of the corpus callosum seen here,

4:35

and this is the area of the septum polysum.

4:37

And hence we have that area called

4:39

the colossal septal interface.

4:41

And that is relatively specific for multiple

4:47

sclerosis as opposed to other

4:49

demyelinating disorders.

4:52

As we go off in the periphery again,

4:55

we see more white matter lesions and you may

4:58

see some out in the peripheral white matter

5:01

again. And this one just off midline.

5:05

We're seeing the pineal gland and the

5:08

tectoplate here. We're just off midline,

5:11

a very nicely demonstrated lesion at the

5:14

colossal septal interface with respect

5:18

to gadolinium enhancement.

5:20

Here we have a patient who has white matter

5:23

lesions in what appears to be the cortex

5:27

going all the way to the periphery.

5:30

So this is a cortical involvement.

5:33

And for that McDonald's

5:38

criteria,

5:39

as well as juxtaportical involvement on

5:43

post-gadolinium enhanced scan again,

5:47

we see the various types of contrast-enhancing

5:52

demyelinating plaques that can occur

5:54

all on one single post-gad image.

5:58

That's why I keep this slide.

5:59

Have the one that is a complete rim

6:03

of enhancement.

6:04

We have the open rim

6:07

or arcs of enhancement,

6:14

we have a more solid contrast enhancement

6:17

and we have some more linear

6:20

enhancing plaques.

6:22

So multiple different of gadolinium

6:25

enhancement by multiple sclerosis plaques.

6:29

For dissemination in time,

6:31

we need to see a patient show either enhancing

6:35

plaques and none-enhancing plaques

6:38

on the same study,

6:39

or plaques that appear and or go

6:43

away on sequential studies.

6:45

So this is the same patient and what one sees

6:48

on this patient is a flare

6:50

scan to the far left.

6:53

On this flare scan, we have the Sylvian Fissure

6:56

and we have the demyelinating plaque.

6:58

On the follow-up scan,

7:00

we have the Sylvian Fissure and you notice

7:02

that the plaque has gone away.

7:04

So this satisfies dissemination in time.

7:08

On sequential imaging,

7:10

you notice that this patient also had a

7:13

peripheral enhancing plaque which no

7:17

longer shows contrast enhancement.

7:20

If we have enhancing plaques and none

7:23

enhancing plaques on the same study,

7:26

we fulfill dissemination in time.

7:28

However, in this case,

7:30

this was the follow-up scan showing that the

7:32

plaque enhancement had resolved. Similarly,

7:36

on the far right-hand side,

7:39

we have a patient who has a peripherally

7:43

enhancing white matter demyelinating plaque,

7:47

which on follow-up, if we track the psilci,

7:53

has resolved another example of a large

7:57

multiple sclerosis plaque, which,

8:00

as you can see, changes in time.

8:03

This was a three-month follow-up.

8:05

So you see a large periventricular

8:08

white matter plaque,

8:10

which on the coronal image showed a sort

8:13

of arc-like solid enhancement.

8:15

On the follow-up scan,

8:17

it decreases in size and it no longer

8:21

shows contrast enhancement,

8:23

fulfilling our dissemination

8:25

in time criteria.