0:00

There is a lot of research being

0:02

performed on multiple sclerosis.

0:04

There's a lot of NIH-sponsored grants on

0:08

multiple sclerosis because, as I said,

0:10

this is the most common

0:11

neurodegenerative disorder

0:13

of young adults.

0:15

And a lot of the research has focused on

0:18

different MR Techniques and what MR.

0:21

Techniques predict the disability

0:24

associated with the patient who

0:26

has multiple sclerosis.

0:27

So we're going to look at a few of these

0:29

research pulse sequences just to wet

0:32

your appetite for what's coming down the

0:36

pike for clinical evaluation as well.

0:39

So I mentioned that seven Tesla imaging

0:42

is quite often performed in the research

0:45

world for multiple sclerosis.

0:47

And we saw some seven Tesla

0:49

brilliant flare imaging.

0:51

Seven Tesla scanners have been approved

0:54

for clinical evaluation of the brain,

0:56

and some sites will be employing seven

0:59

Tesla imaging in their clinical realm.

1:01

However,

1:01

with respect to research protocols,

1:04

I want to emphasize susceptibility

1:06

weighted imaging.

1:07

We are all comfortable now at 1.5 T and

1:10

three T with susceptibility-weighted

1:12

imaging to look for blood products.

1:14

And we note that it also highlights the

1:17

venous system because of the presence of

1:20

deoxyhemoglobin within the veins that

1:22

make the blood vessels dark.

1:24

Well, this,

1:25

coupled with the knowledge that multiple

1:28

sclerosis is a perivenular

1:30

demyelinating disorder,

1:32

allows us to see the active plaques and

1:36

the demyelination around these veins

1:38

even better. So, as you see,

1:40

there are already arrows on here showing

1:43

the dark signal intensity linear veins

1:45

with the demyelination around it.

1:48

But let's just look at this case

1:50

where we have the vein

1:52

and the demyelination. This was present,

1:55

and we saw that on the flare imaging,

1:57

but with SWI,

1:59

we see the veins much better.

2:01

And I think this is a beautiful example

2:03

here of the linear vein surrounded by

2:06

the bright signal demyelination on an

2:09

SWI T2-weighted pulse sequence.

2:12

And this is demonstrated additionally

2:15

on the images

2:16

on the right. Now,

2:19

multiple sclerosis in general

2:21

does not show hemorrhage.

2:23

When we have hemorrhage in association

2:25

with a demyelinating plaque,

2:28

we will think of a different

2:29

differential diagnosis.

2:31

So that's another value of SWI,

2:33

is that we usually do not associate

2:35

hemorrhage with demyelination

2:37

from multiple sclerosis.

2:39

So seven Tesla susceptibility

2:41

weighted imaging. Now,

2:43

others have utilized the susceptibility

2:45

weighted imaging to analyze the iron

2:48

content within the brain and the total

2:52

iron burden of demyelinating plaques.

2:55

So, in this example,

2:56

we have what is known as quantitative

2:59

susceptibility.

3:00

Mapping or QSM,

3:02

and it is a way of grading the degree of

3:06

iron deposition in the brain

3:08

from the demyelination.

3:10

And these are just different

3:12

pulse sequences,

3:13

initially with the flare and with T1

3:16

way and post gadolinium-enhanced scan,

3:18

but down below in DE and F in this

3:21

article by Ravi Menon, we're looking at

3:24

the susceptibility aid scan and we are

3:26

now quantifying the degree of iron

3:29

deposition in the brain from this

3:32

demyelinating disorder of

3:33

multiple sclerosis.

3:35

What he has found is that there is

3:38

indeed increased iron deposition in gray

3:41

matter as well as white matter compared

3:43

to in patients with multiple sclerosis

3:46

compared to controls,

3:47

and that that amount of iron deposition

3:51

correlates best with the expanded

3:54

disability scale for patients with

3:57

multiple sclerosis. So again,

3:58

the idea being how can we correlate

4:02

imaging findings to the degree of

4:03

disability of the patient who

4:05

has multiple sclerosis?

4:07

Other people have used the

4:09

combination of the QSM,

4:12

the quantitative iron content

4:15

with T2* effects,

4:18

as well as gadolinium enhancement to try

4:22

to define the different types of plaques

4:24

that occur in multiple sclerosis,

4:26

including early active plaque,

4:28

late active plaque,

4:30

or chronic plaques that are

4:33

stable if you will.

4:35

And this is one example of a research

4:39

group looking at various combinations to

4:41

define whether a plaque is early active,

4:45

maybe requiring pharmaceutical

4:47

intervention,

4:48

late active on its way to dormancy

4:52

versus chronic plaques.

4:55

And here you can see the different types

4:57

of imaging that is being performed.

4:59

You have the T1-weighted

5:01

post-gadolinium T2-weight scan and

5:04

then the quantitative susceptibility

5:07

mapping and R2* imaging that is

5:12

demonstrating early nodular plaque

5:15

versus early peripheral enhancing plaque

5:18

and the fact that the early nodular

5:21

pattern shows myelin breakdown,

5:23

whereas the peripheral plaque shows some

5:27

myelin degradation but

5:28

not active breakdown.

5:31

The late plaques generally are not going

5:33

to show contrast enhancement seen in the

5:35

upper left image on post-gadolinium

5:37

enhanced scan.

5:38

And you also see that there is some iron

5:43

deposition that's occurring in the late

5:44

plaques and some of the iron content may

5:48

be either in a rim fashion or

5:51

in a more solid fashion.

5:52

So these are just different research

5:55

techniques to try to define stages of

5:58

demyelination within a patient's scan

6:02

who has multiple sclerosis.