0:00

Hi everybody, and thank you for joining us today

0:02

for the third lecture in the remote fellowship course.

0:06

Uh, Dr. McCorey will be reviewing the brachial plexus, Dr.

0:10

McCorey, whenever you're ready.

0:12

Great. All right. What we're gonna do then over the next,

0:15

um, in 50 minutes or so is talk about the brachial plexus.

0:19

Okay? Now the,

0:21

and if you have any questions, um, you know,

0:23

you can come off, uh,

0:25

you guys are both off mute, which is good.

0:26

But if you have any questions, just, just ask.

0:28

'cause again, like I said, I really want you

0:30

to learn the, the information.

0:32

So the brachial plexus really for me encapsulates

0:39

the challenge with head and neck radiology

0:42

because it's really is radiology.

0:44

Nobody wants, um,

0:46

so I don't know Philippe if you were in the first lecture

0:48

today, but you know, it's like head

0:49

and neck radiology is radiology.

0:51

Nobody wants. And so it's really true about brachial plexus.

0:54

And I think part of it is the fact that, you know,

0:57

in medical school, I don't think we really learned

0:59

the anatomy that well.

1:01

And so what, the first half of this talk, the first part

1:04

of this talk, uh, I'm gonna talk about the classic anatomy

1:07

of the brachial plexus.

1:09

And by the way, I just got a brand new writing pen,

1:12

so hopefully this one is gonna work.

1:13

Yeah, there you go. Okay.

1:15

The little PowerPoint thing doesn't work as well now.

1:17

So now I got the pen, which is fun.

1:19

Um, so the classic anatomy,

1:22

the brachial plexus is divided into the roots, the trunks,

1:26

the divisions, the chords and the branches.

1:28

And that's how we learned it in medical school.

1:31

And um, you know, I'm not really one for pneumonics

1:35

and I have a hard time remembering this anatomy.

1:39

What I do remember is this, I can always remember

1:41

that radiology texts drink cold beer, okay?

1:45

And you can change beer to beverages if you want to.

1:47

It doesn't matter. I don't wanna offend anyone,

1:49

but if you remember that radiology texts drink cold beer,

1:53

then you're always gonna be able to remember

1:57

the pneumonics about the brachial plexus.

1:59

So let's start, start with the classical anatomy.

2:03

So the brachial plexus, uh, starts,

2:05

goes from C five all the way down to T one, now C five

2:10

and C six combined to form this upper trunk.

2:14

And C seven forms the middle trunk and then C eight

2:17

and T one form the lower trunk.

2:20

So when you look at this diagram here,

2:22

this is gonna be five, this will be six, this will be seven,

2:26

this will be C eight, and this is T one.

2:29

So you can see how they combine

2:31

and the, the roots form the upper trunk.

2:34

Now what happens with the upper trunks is

2:37

that these trunks end up dividing.

2:39

So when we start looking at this diagram here, this is

2:43

what we're looking at right here.

2:44

We, we, we form the trunks,

2:46

and now they're starting to divide.

2:48

And then if you look real closely, you can see

2:52

they now start to form a new component right here.

2:55

And this component is adjacent to this red structure.

2:59

And that red structure is the subclavian artery.

3:03

So these are the radiology, these are our texts,

3:06

these are our drinking and these are our coal, right?

3:10

I'm not gonna talk about the beer or the beverages. Why?

3:12

Because that really gets into the distal branches.

3:15

And that probably is more applicable to, uh,

3:19

musculoskeletal radiology.

3:21

So it's sort of, if you will, above my head.

3:23

But the cords are named by their relationship

3:26

to this red structure right here.

3:28

And this red structure is supposed

3:30

to illustrate the subclavian or axillary artery.

3:33

Technically it's the axillary artery,

3:36

but we oftentimes just use the subclavian artery

3:39

'cause it's the same anatomic structure.

3:41

It just changed its names as it passes

3:43

through the anterior scap of muscle.

3:45

So these are the roots, trunks,

3:47

divisions, cords, and branches.

3:48

So let me stop there. Do you guys have any questions on,

3:51

on the standard anatomy of the brachial plexus?

3:56

No. No. Okay. All right.

3:59

Yeah, so now what we'll do is,

4:01

we'll now talk about the surgical anatomy.

4:04

Okay? So the surgical, the surgeons have their own anatomy

4:07

of the brachial plexus.

4:09

And that anatomy is

4:11

regarding the relationship with the clavicle.

4:14

Okay? So the supraclavicular

4:18

plexus is com compli comprised of the roots and the trunks.

4:21

So we just talked about the radiology in the text.

4:24

So when we look at the clavicle here,

4:26

we're now talking about the

4:27

supraclavicular plexus being up here.

4:30

Then we have this portion of the plexus that's

4:33

behind the clavicle,

4:35

and that's referred to as a retro clavicular.

4:37

And that's predominantly comprised of the divisions

4:40

of the brachial plexus.

4:42

And then as we get distal to the clavicle,

4:44

now we start talking about the cords of the brachial plexus.

4:48

So you can see that there is an overlap

4:51

and a con consistency between the standard anatomy

4:55

that we talked about, and then also the surgical anatomy,

4:58

which is really based on the clavicles.

5:01

Okay? Are we okay there? Yes. Yes.

5:05

Okay, great.

5:08

Now this is what I refer to as the radiological anatomy.

5:12

So the radiological anatomy is based on three primary

5:17

anatomic structures.

5:19

Those anatomic structures are the anterior scaling

5:21

and the middle scaling muscle.

5:23

And if you look at the image on your right,

5:25

we can see the anterior scaling, which is here,

5:28

and then we can see the middle scaling.

5:29

And this posterior scaling, these two muscles tend

5:32

to be essentially combined.

5:34

It's hard to separate these two,

5:36

but the supraclavicular portion is located

5:39

between these two muscles.

5:43

Now the second component, oh, excuse me,

5:45

this is the axial images.

5:47

So when we look at the axial images,

5:49

this is the anterior scaling muscle here.

5:52

And this triangle right here is the middle

5:55

and the posterior scaly.

5:56

So what's located between the anterior

5:58

and the middle scaling muscle,

6:00

this is the brachial plexus that's located here.

6:03

So the way that I learned the brachial plexus years ago

6:08

was I was always confused with the brachial plexus.

6:10

So what I would start doing is I would actually start to try

6:13

to find the individual components of the brachial plexus.

6:17

But that was really hard to do.

6:19

It's almost like, you know, looking

6:20

for a needle in a haystack.

6:22

Instead, what I realized is if I look

6:24

for these two anatomic structures, the anterior

6:27

and the middle scaling muscle,

6:28

which we always see on a cervical spine, MRI,

6:31

so if you look at the cervical spine, MRI,

6:34

you'll always find the anterior

6:36

and the middle scaling muscle.

6:37

So if you wanna find the brachial

6:39

plexus, that's how you find it.

6:41

So in order to emphasize this, the anatomy,

6:45

what I would suggest you do on the next 20 spine MRIs,

6:48

instead of looking at the spinal cord,

6:51

start looking at the brachial plexus.

6:53

Start finding the anterior inal scaling muscles.

6:56

And then once you do that,

6:57

then the brachial plexus is right here,

6:59

and I'm gonna always jump out at you.

7:02

So similarly, when we look at the opposite side.

7:04

So here's the anterior scaling

7:06

here, here's the middle scaling.

7:07

You can see the brachial plexus there.

7:10

So once you start looking at the big muscles, instead

7:13

of trying to find the little things, you'll always be able

7:16

to find the brachial plexus.

7:19

Now the third piece of anatomy in order

7:21

to find the remainder of the brachial plexus is

7:23

to find the subclavian artery.

7:26

So here's our subclavian artery here,

7:27

and these are the cords of the brachial plexus.

7:31

So in, instead of trying to find the individual cords

7:35

or the components, just try

7:37

to find the big subclavian artery.

7:39

So on this image on the left hand side,

7:42

we can see the subclavian artery.

7:44

See the subclavian artery right here.

7:46

And then right above it are gonna be the cords

7:48

of the brachial plexus just laying on the subclavian artery.

7:52

So similarly, when we look at this, Mr,

7:54

on your right hand side,

7:56

it's a fat suppressed T two weighted image.

7:58

There's actually like a stir sequence,

8:00

but I think it's actually a fat suppressed T two.

8:02

When you look at it, there's a lot

8:04

of complex anatomy, right?

8:06

So what you have to do is say, aha,

8:08

here's the brachial plexus right here,

8:11

and here's the brachial plexus right here.

8:13

And then right above it are gonna be core

8:15

to the brachial plexus,

8:17

literally lying on the subclavian artery.

8:20

So that's how you can identify the brachial plexus

8:22

and the subclavian artery.

8:24

It's a very, very simple approach to this.

8:27

Okay, now this is the sagittal image.

8:31

So this is actually the way that I learned

8:32

to read the brachial plexus back when I was in,

8:35

in as a resident.

8:36

And I remember my attendings would always say, well,

8:40

the way you learn the brachial plexus is on the sagittal

8:43

limit is, well, it took me about 10 years later to realize

8:46

that's the worst way to learn the brachial plexus.

8:48

Because if you start looking at the sagal images,

8:51

you're not really used to looking at sagal anatomy.

8:54

Now all of a sudden you have to figure out

8:56

where the clavicle is.

8:57

You have to figure out where the jugular vein is.

9:00

Here's the anterior scaling muscle,

9:01

here's the posterior scaling muscle,

9:04

here's a subclavian artery,

9:06

and these are the cords of the brachial plexus located here.

9:09

So yes, you can see all those components,

9:12

but for me, the sagal image is actually the hardest plane

9:15

to look at because not only do you have to know the anatomy,

9:18

but you also have to look at it in a different plane.

9:21

So that's why I always recommend when you're first learning

9:23

the brachial plexus, just look at the axial planes

9:26

and then look at the coronal planes.

9:30

Okay. Alright.

9:31

Any questions for that Philippe

9:35

or ize or gory?

9:37

I see you guys joined. Okay.

9:40

Philippe gave a thumbs up, so thanks, please.

9:44

Or gory, you can go on. I'm at home today,

9:46

so you can actually turn on your, your cameras if you want.

9:50

Um, 'cause I think I have enough bandwidth at home.

9:52

Hey Belize ize, I saw you this morning too. Good lecture.

9:57

Yeah. Yo, thanks for coming. Go. Hey Gorie, how are you?

10:01

What time is it in India? It looks like it's light outside.

10:05

Uh, Melissa, it's 9:00 PM

10:07

9:00 PM Oh, oh, you're in your office.

10:09

Okay, I got it. Good. Okay, good. Alright. Right. Okay.

10:14

So now what we're gonna do is

10:15

that we're gonna talk about the reasons

10:17

that you end up getting, um, brachi a,

10:20

a brachial plexus, Mr.

10:22

And the reason you end up getting a brachial plexus, Mr, is

10:25

that you have something that's referred to

10:27

as a brachial plexopathy.

10:29

So brachial plexopathy are patients

10:32

that have clinical symptoms that present

10:34

with supraclavicular or shoulder pain.

10:37

The pain can be worsened by palpation or movement

10:40

and they can also be associated

10:42

with the palpable abnormalities.

10:44

So this is what we mean by a brachial plexopathy.

10:47

Now there are various etiologies that are associated

10:50

with a brachial plexopathy.

10:52

It could be due to trauma, it could be due

10:54

to vascular compression, it could be due to tumor,

10:58

or it could be due to any type of inflammatory processes.

11:01

So the first thing that we'll start out talking

11:03

about is trauma.

11:06

So the two most common types of trauma that can occur,

11:10

the result in a brachial plexopathy are some type

11:13

of birth trauma or some type of vehicular injury.

11:17

So back when I was a resident, um, when I, when we could as,

11:21

as, as I should say, as a medical student,

11:23

when we could still deliver babies, it's been a heck

11:25

of a long time since I've delivered baby, thank God.

11:28

But the thing is that when you deliver a baby

11:30

through a re regular vaginal delivery,

11:33

what ends up happening for

11:35

to result in a brachial plexopathy is the OB ends up,

11:38

you know, gently uh, putting the hands over the head

11:41

and gently pulling

11:42

and assisting the baby coming through the vaginal vault.

11:46

But the challenge is, is

11:47

that we can see the pubic synthesis right here.

11:50

And if this shoulder gets caught adjacent to the synthesis

11:54

as the OB is trying to pull the head out,

11:56

the shoulder gets caught.

11:58

And this results in a stretching right here

12:00

of the brachial plexus.

12:01

So that's what we mean by this whole concept

12:04

of shoulder dystocia.

12:06

And the area that is most likely to get involved by this

12:10

shoulder dystocia is that it could injure C five

12:13

and it could injure C six.

12:15

So as a result, what you end up ending up with is

12:19

that you end up having an abduction, internal rotation

12:23

and pronation of the forearm.

12:25

So that's what happens when you have AC five

12:27

or AC six injury.

12:31

Now this other one, and I probably should remove this slide,

12:34

but I just kinda like to show it

12:36

'cause it kind of, again, life is about storytelling.

12:38

And it reminds me of the stories back when I was a medical

12:41

student is that the other injury was what we referred to

12:45

as the clunky palsy.

12:47

So the clunky palsy was actually an injury to C 17 one.

12:52

Now what clunky palsy was, is if I go back to this slide,

12:56

instead of the head coming out,

12:57

the tail would end up coming out.

13:00

So in this case, when when the head is being pulled through,

13:03

you're having stretching here, if you had turned it opposite

13:06

and the tail came through, then the shoulder gets stretched.

13:11

But on the other hand, the arm gets caught

13:14

and the tail comes out.

13:15

So it's actually a stretching motion like this.

13:18

And this is what results in C seven through T one palsy.

13:22

Now what's happened in the U United States

13:24

and probably worldwide as well, is

13:27

that rarely do you now have vaginal deliveries that are

13:30

through the breach position,

13:32

but at that time, this is

13:33

what would end up causing the C seven three T one.

13:38

Now not only do you have a paralyzed claw hand

13:41

because this is gonna affect C seven T one,

13:44

but does anyone know why you would end up having o

13:46

ptosis and a myosis?

13:48

The answer's on the slide,

13:57

um, please are go ahead.

14:03

Yeah, exactly, exactly right.

14:05

So C seven and T one actually innervate the stella ganglion.

14:09

And so if you elevate the Stella ganglion,

14:12

that's why you end up getting H ptosis

14:14

because basically you're causing a somewhat

14:16

of a Horner syndrome because they supplied

14:18

the sympathetic chain.

14:20

And remember, a Horner syndrome results from some type

14:23

of disruption in the sympathetic chain.

14:25

So that's why you'll get the C seven T one

14:27

and this can result in sort of the thes,

14:30

I call it like it's probably a,

14:31

I dunno if it's a really true hor syndrome,

14:33

but we'll call it hor syndrome light

14:35

because it can give you the posis end, the myosis.

14:41

Now what about in trauma?

14:43

Well, how do you work up these patients?

14:45

Well, you can work these patients up with MR

14:47

or you can work them up with ct.

14:50

So this is an example of a normal appearance right here

14:53

and we can see the ventral root

14:55

and we can see the dorsal root.

14:57

Everyone see the ventral and the dorsal root? Yes.

14:59

Now notice on the left hand side we see the ventral root

15:02

and we see the dorsal root,

15:04

but we don't see any roots on the left hand side.

15:06

So typically what happens with the pseudomeningocele,

15:09

I don't think this is gonna work.

15:10

Yeah, this is an older, older uh, movie.

15:14

It doesn't work with this new new um, version.

15:17

But the point is, is

15:18

that in in general when when you have a pseudomeningocele,

15:22

you should typically see disruption of the nerve roots.

15:25

And I gotta tell you for me, I'll tell you a story.

15:28

Back when I, when I went to University of Michigan,

15:31

before I went there I was just used

15:32

to doing Mrs on everyone.

15:34

But we had some, if you will,

15:35

conservative old time experienced surgeons

15:39

and they would always want to do CT myelograms.

15:42

And so I gotta tell you, for the CT myelograms I had

15:44

to learn how to do 'em in kids.

15:46

They're actually pretty easy to do.

15:48

But what it does teach me was that man,

15:50

you could really see those ventral

15:52

and dorsal nerve roots really easy on CT myelography,

15:55

you can see it very, very consistently.

15:58

So here's a typical example of a patient

16:00

that had a shoulder dystocia.

16:02

This was a birth injury

16:03

and we can see the typical pseudomeningocele involving the

16:07

um, the area of the nerve roots.

16:12

Now granted you can see the nerve roots pretty well with mr.

16:16

So this is a nice example

16:17

of a ventral the dorsal nerve roots.

16:19

So don't get me wrong, I think if you do really good

16:22

Mr, you can see it.

16:24

Well the challenge is, is that depending on your practice,

16:27

you know, if your patients move a lot then you may not have

16:30

the clarity to actually see the ventral

16:32

and the dorsal nerve roots consistently.

16:34

And for me it's all about consistency.

16:36

You know, which imaging study am I going to get

16:39

that's gonna allow me to view these more consistently.

16:41

So that's why uh, MR can be great

16:44

but just realize it can be affected by motion artifact.

16:48

Now this is an example of a total plexus avulsion.

16:52

So let me move your little screen right here.

16:55

So this was a patient that had a motor vehicle accident.

16:58

Now if you look at the normal brachial plexus on the right

17:01

side, you can sort of see the linguini right here.

17:03

So this linguini shaped appearance of the brachial plexus.

17:07

But on the left hand side, on the stir images, notice

17:10

how these nerve roots,

17:11

or I should say the cords

17:12

of the brachial plexus are thickened.

17:14

And there actually looks like a little disruption right here

17:17

between this portion and this portion.

17:20

So this is what we'd expect

17:21

to see at a total plexus emulsion.

17:24

Now the image on the right is a pace

17:26

that ended up having a CT myelogram.

17:28

And when you have the CT myelogram,

17:30

you can see this extra uh, uh, collection

17:34

of contrast which you normally shouldn't see when you

17:37

perform myography.

17:38

So in this case, what we ended up seeing was

17:41

that the contrast material was extending out

17:43

through the brachial plexus and

17:45

because of the extravasation we started seeing these

17:47

collection of contrast outside of where it should be.

17:50

So this is the MR appearance

17:52

and the CT appearance of a total plexus uls injury.

17:57

Alright, so let me stop there.

17:58

Do you guys have any questions about trauma? No.

18:04

Is it clear Andrew, is it clear?

18:08

Yes. Yeah, Okay.

18:10

You're the resident of the group,

18:11

you're the junior resident.

18:12

I think you have other residents,

18:13

but I think you're the youngest one,

18:15

so right Valerie, you good with that?

18:20

Okay. Alright, so the next thing that we'll do is

18:22

that we'll now talk about vascular compression.

18:26

And so, um, this was actually kind of funny last night.

18:29

Last night I went to a dinner

18:32

and the dinner there was some,

18:34

there were some residents there

18:35

and one of them had actually listened to this talk

18:38

before, it may have been on YouTube

18:40

or something if you guys want to have a YouTube channel

18:42

so you can, you know, you can subscribe

18:44

to it, it's free or whatever.

18:46

But they actually went to my channel.

18:47

They said, I remember this talk on the brachial plexus

18:50

and you talked about a patient with lead poisoning

18:53

and I'm like lead poisoning.

18:54

And then I realized they were talking

18:56

about this case right here.

18:57

Anybody, you know what this is right here.

19:05

Anybody that's a bullet.

19:09

So this was a patient that was shot in the right chest

19:13

in the right upper chest.

19:14

And this bullet right here actually injured the

19:17

subclavian artery.

19:19

And so what happened after the injury?

19:20

This is an old conventional angiogram

19:22

and we can see a pseudo aneurysm here

19:25

and we can see a big pseudo aneurysm that's located here.

19:28

So what happened in this case is that this patient presented

19:32

with a right-sided brachial plexopathy.

19:34

So Matt Morrow, who I worked with, Matt's the president of

19:38

of RSS NA this year.

19:39

You've probably heard of RSS NA, he's the president

19:41

of RSS A this year when he was an interventionalist,

19:44

or he still is, I should say.

19:46

He ended up stenting this.

19:47

And you can see the stent crossing over the subclavian

19:50

artery and you can see there's complete reduction

19:53

of the pseudo aneurysms.

19:54

So this was a case where the patient's symptoms actually

19:57

improved after they put that stent in.

20:01

And here's another example.

20:03

So this is another example of a pseudo aneurysm,

20:05

but the thing you always have to remember is that

20:09

normally these things can arise.

20:11

What involves a subclavian artery?

20:13

It arises in the supraclavicular fossa.

20:15

So if you see something like this,

20:17

you can see this mass is actually high T one signal,

20:20

but it's not nearly as high as the fat.

20:23

So the point is, anytime that you see a mass right here,

20:26

if a palpable mass, if the surgeon feels a palpable mass,

20:29

oftentimes they're gonna biopsy this.

20:31

So part of our job is to say, hold on for a second,

20:34

there's something there that tells me

20:36

that this is not gonna be a tumor.

20:38

And we can see that T one shortening

20:41

and this represents the blood products.

20:43

And in fact when we look at the sagittal images,

20:45

so here's anterior here and posterior is back here.

20:49

Here's the clavicle.

20:51

You see this little lumen right here, that's the lumen

20:54

of the subclavian artery.

20:55

And then with the leap of faith, you can sort

20:57

of see this world appearance right here.

21:00

So that's active extravasation of blood.

21:02

And this high T one signal more periphery is the met

21:06

hemoglobin in the blood products.

21:07

And this thick wall right here,

21:09

this thick wall is actually the capsule.

21:12

So that's actually a fibrous capsule

21:14

that formed from the Cino Aly.

21:16

So the bottom line is

21:18

that when you do see these masses in the supraclavicular

21:20

fossa, just realize

21:21

that the subclavian artery does live there.

21:24

And part of what you have to be able to do is make sure

21:27

that you're not dealing with the pseudo aneurysm.

21:31

Alright, any questions on vascular compression?

21:36

No, none.

21:41

Was that a no Philippe or or could tell? None. None.

21:44

No poor guy man, you look like you're falling asleep.

21:47

Oh my gosh, it's probably 11, 11 30 right now.

21:50

So, but it's fun having people from Hungary, Philippines,

21:54

the US and India.

21:55

It's kind of, it's the, it's a cool thing. I enjoy it.

21:58

Alright, so now let's talk about tumors.

22:00

All right, so when we talk about tumors,

22:05

I try to be really simple in this, okay?

22:08

Remember the brachial plexus is a neural structure.

22:11

So as a result, when you have tumors

22:13

that involve the brachial plexus, we should think about it

22:16

as nerve sheath tumors or non nerve sheath tumors.

22:20

Very, very simple. Right now if you have a nerve sheath

22:24

tumor where you can have benign lesions

22:26

and you can have malignant lesions, fair enough.

22:30

On the other hand, if you have non nerve sheath tumors,

22:32

you can have benign lesions and malignant lesions.

22:35

So it's a very simplistic approach, right?

22:37

Because I'm sort of a simplistic guy. All right?

22:39

I just like to kind of boil things down

22:41

and try to make it as easy as you can.

22:44

So when we talk about benign nerve sheath tumors,

22:47

what do you think are, what are the things

22:49

that you would think of when you think about benign nerve

22:52

sheath tumors involving the brachial plexus?

22:54

Before I go to the next slide,

22:55

what would you guys think about

22:58

One more?

23:00

Yeah, beautiful. Exactly, exactly right.

23:05

So the neurofibromas

23:10

in the literature are actually the most common

23:14

primary nerve sheath tumor.

23:16

About two thirds of these are sporadic

23:19

and about one third are associated with NF type one.

23:23

And if they're associated with NF type one, then they tend

23:26

to be multiple and they tech tend to be plexiform.

23:30

Okay? Now the thing about neurofibroma is

23:33

that if you look at the nerve, and I don't think I have an

23:35

illustration of this talk,

23:36

but basically you have a nerve like this that's surrounded

23:40

by schwan cells, right?

23:41

The schwan cells is the myelin, that's that

23:43

that forms this periphery here.

23:45

But within the nerve itself you have multiple neuro

23:48

fibrils, okay?

23:50

So a neurofibroma is that when you have this tumor

23:54

actually arising from these individual neuro fibrils, so

23:58

that gives you this plexiform appearance to it.

24:01

A schwannoma on the other hand is going

24:03

to be arising from the periphery of the nerve

24:06

because the schwan cells contain myelin.

24:08

So as a result, when you talk about neurofibromas,

24:12

you hear this thing that they're unencapsulated

24:14

and the reason they're unencapsulated is they're actually

24:17

arising from these individual nerves.

24:20

So this typical imaging appearance of neurofibromas,

24:24

they tend to be iso to hypo attenuation of muscle.

24:28

They may or may not enhance on ct

24:30

and they may be associated with mode

24:32

and remodeling on T one.

24:34

They're ISO intensity muscle, they often enhance

24:37

with contrast and they may have increased signal.

24:40

So here's some examples. Now let's analyze this image.

24:44

Okay, normal or abnormal, draw a line down in the middle,

24:48

compare one side to the other side, right?

24:51

So it's abnormal. Mm-hmm.

24:53

Okay, so you look at this

24:54

and what's the first thing you think about?

24:56

Could this be a sarcoma? Could it be a lymph node? Right?

24:59

Sort of goes through your mind.

25:01

But now that you understand the anatomy,

25:04

what you wanna do is analyze this on

25:07

the T two weighted images.

25:08

So if you look at the left side,

25:10

you can see the anterior scaling here.

25:12

The middle scaling here

25:13

and between the anterior middle scaling muscles

25:16

is the brachial plexus.

25:18

And on the left hand side, see

25:20

how the anterior scaling is here, see

25:22

how the posterior scaling is here?

25:24

And these lesions are located between those two muscles.

25:28

So as a result, this has

25:30

to be arising from the brachial plexus.

25:32

Does that make sense to you? Yes. Yes.

25:35

And even when you look at the contrast enhanced study,

25:37

so the contrast enhanced T one weighted image,

25:40

we can see the enhancing here.

25:41

They look like little cannonballs.

25:43

You notice the anterior scaling

25:45

and the middle scaling muscle.

25:47

So basically if you understand the anatomy

25:50

and you sort of just take, take a step back,

25:52

then you can come up with the right diagnosis

25:55

of these lesions involving the brachial plexus.

25:59

Another example here, if I would've shown you this

26:02

before, you may have said

26:03

that these are multiple lymph nodes,

26:05

but actually when you look at it,

26:06

you can see the anterior scaling here,

26:09

the anterior scaling here and there's this posterior scaling

26:13

and there's the posterior scaling.

26:15

So in this particular situation, um,

26:18

another in this particular uh, situation, again,

26:21

you can see these lesions are rising in the brain

26:24

of the anterior and the middle scaling muscles.

26:27

So we can make the diagnosis of neurofibromas.

26:30

Another example here,

26:31

I think we'll all make this a beautiful example here

26:34

of the sausage shaped plexiform neurofibromas

26:37

that are involving the nerve roots.

26:41

Now what about schwannomas?

26:43

So this is the exact same slide that I showed

26:47

before about for neurofibromas.

26:49

So from a single solitary lesion,

26:52

you can't tell the difference.

26:54

So here's an example of a schwannoma.

26:56

Now does anybody see it?

26:57

Is it on the left hand side or is on the right hand side,

27:02

Right?

27:03

Right, exactly. So how do we analyze this image?

27:06

What muscle is right here?

27:09

Anterior skin And right here,

27:13

The middle and posterior skin.

27:14

Exactly. And so what are we looking at right here?

27:19

Brachial plexus. Exactly. Isn't it easy?

27:22

Brachial plexus is easy, right?

27:24

If you want something hard, go do mammography right?

27:27

Now on the other hand, here's the anterior scaling here,

27:30

here's the middle scaling here.

27:32

And you see this mass right here.

27:34

So you may say, now hold on,

27:35

is that a lymph node right here?

27:37

But where my eye goes

27:39

to is I can see this extending medially

27:41

and it's going to the plains of these two muscles.

27:44

So therefore I know

27:46

that this is arising from the brachial plexes.

27:49

So in this case it's a schwannoma.

27:51

Could this be an isolated neurofibroma? A hundred percent.

27:54

There's no way that I could really tell the difference

27:56

on a single lesion.

27:58

Another example here we can see this mass right here.

28:01

Now you look at it and you're

28:03

saying, now what could that be?

28:04

Right? Could this be a little cyst?

28:06

Could it be a lymph node?

28:08

Could be metastatic thyroid cancer, right?

28:11

These are all sort of things you think about,

28:13

but if you look real closely,

28:14

there's the anterior scaling here,

28:16

here's the posterior scaling here,

28:18

and look how it's separating this one anterior

28:21

and this one posterior.

28:23

So therefore you know it has

28:24

to be arising from the brachial plexus.

28:26

And that way you can suggest a diagnosis of a schwannoma.

28:31

Now this was a case that I saw years ago

28:34

and um, this is back when I was at UNC again, like I'll,

28:37

I'll show the older cases just because they're stories.

28:43

And so I looked at this case

28:44

and this was a patient that had a palpable mass involving

28:47

the right neck and our surgeon felt it

28:49

and every time he felt it,

28:51

the patient had pain radiating down the right arm.

28:53

It was like a shock. And so I read, I say T,

28:57

and basically the CT I think was read I think

29:00

three times it was negative.

29:01

I think I read two of them. So I was sort of at fault.

29:05

So if you look at it, does anyone see anything here?

29:19

It's on the right side, right?

29:22

Yeah. Where here, Yes,

29:28

You're better than me.

29:30

So that's where it is.

29:31

So when you actually look at the right side,

29:33

I call this negative maybe

29:34

where the leap of faith is right here.

29:36

I think if you saw that then I,

29:38

Andre you should be giving the lecture and not me.

29:40

So that's a good pickup.

29:43

And so when you look at the contrast enhanced T, one way

29:46

to them, which is you can see the anterior scaling here,

29:48

the middle scaling here,

29:50

and then right here is the schwannoma.

29:53

So this patient ended up having a schwannoma

29:54

involving the brachial plexus.

29:56

So a couple lessons on this is that I, at that time,

29:59

even though you can see schwannomas,

30:02

MR is still probably superior to CT

30:04

for identifying these little schwannomas

30:06

involving the brachial plexus.

30:08

Now we talked about nerve C tumors, benign.

30:11

Now let's talk about malignant nerve C tumors.

30:15

So the main primary malignant tumor

30:19

that will involve the brachial plexus,

30:21

we've changed the name again.

30:22

So now what's called malignant peripheral neuro tumors,

30:26

we used to call it neurofibromas neuro fibrous Sarco.

30:29

In fact, I need to change this slide.

30:30

So it should be M-P-N-S-T.

30:34

So I'm getting old

30:36

and crotchety, I hate it when they change the names

30:38

of something that I've called it

30:39

and they just changed the names and now I've gotta learn it.

30:41

But so the bottom line is is that they arise in about 10%

30:46

of patients with neurofibromatosis type one.

30:49

And my son is actually doing research on neurofibromatosis

30:52

and he tells me that they're still giving radiation therapy

30:55

to patients with uh, neurofibromas.

30:57

And so as a result there, this can be a delayed complication

31:02

of patients in NF that are treated with radiation therapy

31:06

on a single study.

31:07

We can't differentiate benign versus a

31:10

malignant nerve sheath tumor.

31:12

So on a single study we can't differentiate a neurofibroma

31:16

from a neurofibroma,

31:18

but this is an example

31:19

of a malignant per peripheral nerve seat tumor.

31:22

So let's analyze this.

31:24

So this right here is the subclavian artery.

31:26

See the subclavian artery right here.

31:28

And in this case there's a subclavian artery right here.

31:31

And you can see that this mass right here is sort of linear

31:35

and it's thick and it's growing along the expected location

31:39

of the brachial plexus.

31:40

And when we look at the contrast enhanced T one weighted

31:43

images, we can see that it's homogeneously enhancing.

31:46

So when you see something this big, then you have

31:49

to consider the possibility of a malignant tumor.

31:52

Now yesterday I read out as part of the RS NA

31:55

with this group in Tanzania

31:57

and we saw a case yesterday of a 15 year old child, one five

32:02

that apparently has a family history of NF

32:05

and it looks like the patient has nf,

32:06

but there's this big mass in the left side of the neck

32:09

that looks pretty ominous.

32:11

So I'm hopeful that they'll biopsy this to determine whether

32:15

or not that could be a neurofibroma

32:17

or it's actually gonna be a neurofibroma.

32:19

But again, on one individual image it's kind of hard to say,

32:23

alright, let me stop there.

32:25

Any questions about nerves? Tumors so far?

32:27

Are you confused or did that, did

32:29

that kind of make sense to you?

32:33

Makes sense, makes sense. Okay, great. Okay, fabulous.

32:38

All now we'll go to non sheath tumors.

32:42

So when we look at non nerve sheath tumors,

32:45

this one is a good example

32:47

of quote unquote a non nerve sheath tumor

32:49

that involves the brachial plexus.

32:51

So I think we could all make the diagnosis right.

32:53

This is just a straightforward lipoma.

32:56

So this patient presents and look at the skin right here.

32:59

See how the skin's a little convex right here.

33:02

This was a patient that has a lipoma.

33:04

Here's the lipoma that's located here.

33:06

In fact, it fat suppresses here.

33:09

But the reason for getting the MR study is not to say

33:12

that this is a lipoma.

33:14

The issue is, is is to determine what,

33:16

when the surgeon operates on this,

33:19

is the patient gonna be at risk

33:21

for developing a brachial plexus injury?

33:24

So what we have to be able to do is look at the deep portion

33:27

of the lipoma, here's the subclavian artery

33:30

and notice we can see the cords of the brachial plexus.

33:34

So the real value add to this is not say

33:36

that this is a lipoma to say that the deep margin

33:40

of this lipoma is directly abutting the cords

33:43

of the brachial plexus.

33:44

So that's the real value of what we're doing.

33:47

Here's another example again, a bit of an older case.

33:51

This was a patient that had a human angio.

33:54

Here's the subclavian vein, here's the subclavian artery

33:57

and here's the brachial plexus.

33:59

This is all he angioma right here involved in skin surface.

34:03

But notice how the deep margin

34:04

of the he angio is directly abutting the brachial plexus.

34:08

So in this case, this was years ago,

34:10

they were actually contemplating resecting it.

34:12

It was definitely not the right thing to do it.

34:14

Uh, that certainly now,

34:16

but the real issue is, was it involving the brachial plexus?

34:19

And we can say yes

34:20

because this enhancing mass is directly adjacent

34:22

to the cords of the brachial plexus.

34:26

Then you can also have malignant lesions

34:28

that are non nerve sheath tumors.

34:30

So we're sort of stepping through this

34:33

and these can be divided into direct extension from a

34:37

pancoast tumor or a potentially metastases.

34:41

So here's an example of a patient that has a pancoast tumor.

34:46

So these are sometimes known as superior sulcus tumors.

34:49

So this is the nice netter diagram

34:52

demonstrating the superior sulcus tumor

34:54

extending into the apex.

34:55

Here we can see the involvement of the brachial plexus.

34:58

So in the image on the right here, we can see this tumor

35:01

and see how it's obliterating the fat

35:03

and right above it are gonna be there towards

35:05

the brachial plexus.

35:07

So that's why patients

35:08

with panco tumors end up having a right brachial plexopathy

35:12

'cause these tumors grow through the lung apex

35:15

and involve the components of the brachial plexus.

35:20

Now metastases are interesting too

35:22

because in general we already know

35:25

that the patient has metastases.

35:27

Why? Because just ask the patient, they'll tell you

35:29

what the primary tumor is.

35:31

So this is an example on your right hand side of a patient

35:35

that has a metastases.

35:37

Now does anybody see what metastasis is?

35:40

Is it AB or C?

35:44

C, e? What's that?

35:48

C, CC. Yeah, exactly.

35:50

Right now brachial plexus is easy, right?

35:53

So where is the metastasis? Is it gonna be here?

35:58

Is it gonna be here or here? It's actually here.

36:00

And here we can see it growing through the anterior,

36:03

the middle scaling muscle.

36:05

So by now I've been,

36:06

I've been harping on the anterior in the middle scaling

36:09

so much that it should jump out at you, right?

36:11

In fact, the next time you look at a cervical

36:13

spine, ignore the cord.

36:15

It's an accessory organ of the neck, right?

36:17

So what I want you to do is concentrate on the anterior

36:20

and the middle scaling muscles

36:22

and then you'll never forget

36:23

where the brachial plexus is located.

36:26

Here's another example again, let's use that same construct.

36:30

Take a look at this side.

36:31

We have a patient here, a large metastasis on the left.

36:35

How do we know that it's involving the brachial plexus?

36:38

We know it's involving the brachial plexus

36:40

because what structure am I looking at right here?

36:43

Subclavian artery. Exactly, exactly. Subclavian artery.

36:48

And we can see all of this enhanced tumor right here.

36:50

You can the subclavian artery.

36:53

So therefore we know it has

36:55

to be involving the brachial plexus

36:59

and then the, okay, let me stop right there.

37:01

Any questions on any questions on tumors

37:04

involving the brachial plexus?

37:10

No. You with me? Yes. Okay. All right, good.

37:15

Then the last thing that we'll talk about are inflammatory

37:18

processes involving a brachial plexus.

37:20

And this can be due to patients treated

37:23

with cryo radiation therapy.

37:25

They can be idiopathic or they can potentially be fona.

37:30

So the most common reason we end up getting brachial

37:33

plexopathy in patients that have been previously treated is

37:37

to look for, determine whether

37:40

or not we're dealing with radiation associated brachial

37:43

plexopathy versus recurrent tumor.

37:46

Now this is an example of a patient

37:48

with radiation associated brachial plexopathy

37:52

and this is the star image

37:54

and this is the, I think the DWI image

37:57

and we can see abnormal signal here.

37:59

So the question is, is that, you know, how do I know,

38:03

uh, let me put it this way.

38:04

Uh, is there anything that that tells us any tricks

38:08

that we can use that can lead us to suggest

38:11

that this is actually due to radiation associated

38:15

as opposed to recurring tumor?

38:17

So here's some tricks that I've learned.

38:19

First of all, there has to be radiation therapy delivered

38:23

to the base, the net.

38:24

So what type of tumors do you think would be at risk

38:28

for developing radiation associated brachial pathy?

38:31

There are three or four. Anybody want to take a guess?

38:34

Um, breasts Breast. Breast is one. What else?

38:39

Uh, panco tumor panco tumor lung tumors, right?

38:45

And then the other thing too is that if you have a lot

38:47

of bulky disease involving the head

38:49

and neck, that can cause that.

38:51

And also if you have Hodgkin's disease

38:53

and they radiate it with,

38:54

with radiation therapy, that can cause it.

38:57

So first of all, the radiation has

38:59

to be delivered to the lower net.

39:01

The second thing is that radiation associated brachial

39:04

plexopathy results in fibrosis

39:07

and the higher the li the li, there's gonna be a higher like

39:10

of developing fibrosis if you give a higher dose.

39:14

So if the dose is 5,500 gray

39:18

or more, then there's a higher likelihood

39:21

of develop radiation associated brachial plexopathy.

39:24

Now look at it the other way.

39:26

Let's just say if you have a mass down the base of the neck

39:28

and they'll say, you know what?

39:30

We just treated this person about um, six weeks ago,

39:34

or I should say six months ago and we only gave 4,000.

39:39

Well that 4,000 is really too low

39:41

to develop radiation associated bra, brachial plexopathy.

39:45

So in my minds I am thinking well maybe there's a higher

39:48

likelihood of recurrent tumor

39:50

because I know there has to be a higher dose

39:53

to develop uh, fibrosis.

39:55

So these are all the things that that I think about too.

39:58

And finally, if they did concurrent chemotherapy, well

40:01

that can predispose as well too.

40:03

So these are some associated factors

40:05

that can help us arrive at that correct diagnosis.

40:09

Another example here

40:11

of radiation associated brachial plexopathy.

40:13

Again, the only thing I can tell you

40:15

for me it almost looks like this sausage shaped appearance.

40:19

And then when we look at the contrast enhanced study,

40:22

again we can see diffuse thickening in this case along the

40:25

roots divisions, trunks and cords of the brachial plexus.

40:29

So I look for that sausage shape appearance

40:31

and that is more indicative

40:33

of radiation associated brachial plexopathy.

40:37

Now this is a example of a familial cause of

40:40

of brachial plexopathy.

40:42

So I was actually a visiting professor years ago with

40:45

that Ottawa hospital up in, up in Canada

40:48

and I was just kind of hanging around

40:49

and they showed me this case and lo

40:52

and behold when I looked at this case,

40:53

here's the normal subclavian artery on the right side,

40:56

there's a subclavian on the right side.

40:58

And lo and behold, look at these diffuse thickening

41:01

of the brachial plexus.

41:02

So this is an idiopathic inflammatory neuropathy involving

41:07

the brachial plexus.

41:08

So this could be something like charco sort of,

41:11

I don't wanna say it's CMT

41:12

but something like that, you know, an idiopathic uh,

41:15

neuropathy that was involved in the brachial plexus.

41:18

And here we can see the diffuse thickening on the

41:20

non-contrast T one wayed images and high T two signal.

41:24

So again, this is an idiopathic type of brachial plexopathy.

41:30

So this is something of a brachial plexopathy

41:33

that we all had to learn about, you know, a few years ago.

41:37

So this was a case

41:38

of covid vaccine related brachial plexopathy.

41:42

And I dunno if I've told you the story,

41:44

but there was a couple of cases here

41:45

and this is again sort of a fun one.

41:47

So this was a patient that had a history of melanoma

41:51

and was treated and when we looked at this we can see this

41:54

abnormal enhancement right here involving paraspinal muscle.

41:57

So this was re biopsy proven recurrent melanoma.

42:01

Now when we looked at the PET scan, all

42:04

of a sudden we started to see these areas

42:05

of increased uptake involved with the lymph nodes.

42:08

So the issue was is this localized melanoma

42:12

or is this diffuse melanoma?

42:15

I remember this patient and you know this at the time

42:19

was just coming out that covid vaccines were associated

42:22

with reactive adenopathy.

42:24

So this patient

42:25

to make things even more complicated

42:27

had a history of breast cancer.

42:28

So then we're really stuck.

42:30

Yeah, well it turns out about three weeks

42:33

before the patient had a left-sided covid vaccine,

42:36

so they actually went in

42:38

and resected one of these lymph nodes

42:39

and it turned out to be a reactive lymph node.

42:41

So this was felt to be pathologically proven reactive, uh,

42:45

axillary adenopathy from covid vaccine.

42:49

So then about, I think about like this was in June I think,

42:53

so this was back back in I think like in February or March.

42:57

So then in June I open up, I come to work

43:00

and uh, you know, they like

43:02

to send me the brachial plexus studies.

43:03

So I open up and on Monday morning I get two

43:05

brachial plexus studies.

43:06

I'm like, well this is great. So lucky me, right?

43:10

So I open up and I look at this case

43:13

and I'm like, huh, this is kind of interesting.

43:16

The patient patient has a left-sided brachi osteopathy.

43:19

And I started looking at these lymph nodes right here

43:21

and I'm like, huh, those are sort

43:22

of some reactive lymph nodes

43:24

and you can see the lymph nodes right here.

43:26

And I don't know a soft call,

43:29

but you know, there's a little bit

43:30

of increased signal here involving the brachial plexus.

43:33

So what I ended up doing is I ended up calling the

43:35

orthopedic surgeon up and he said, um, he said, yeah,

43:40

I know that that case that there's um, uh, there

43:44

it's a concert violinist, it's like a 16 year old

43:47

and the mom wants them to be a concert violinist

43:50

and they've been playing the violin a lot

43:51

and I actually think it's due

43:53

to a neuropathy from too much violin planning.

43:56

'cause you know, in violin you have

43:57

to like hold your elbow like this.

43:59

They thought, yeah, I think it's due to the violin.

44:01

I'm like, have they had a covid vaccine?

44:04

They said, no, I don't think so. I'm like, all right.

44:07

And then he goes, well what about the sister?

44:09

I'm like the sister. And then lo

44:12

and behold, the next case I open up is the sister.

44:15

And so this is the sister case number two.

44:19

And again, we can see big and large lymph nodes right here.

44:23

And now we can have a little bit more of a suggestion.

44:26

Notice how there's more signal on the left

44:28

compared to signal on the right.

44:30

So this again started to look like a neuritis.

44:33

So now I'm thinking to myself

44:35

and I talked to the surgeon, he says, yeah,

44:37

I think they both have viral neuritis due to the, to,

44:40

to playing the violin.

44:42

And now I'm really starting to wonder, I'm like, really?

44:44

Seriously? You think two sisters both have neuritis from

44:48

playing the violin?

44:49

And he swears they didn't have a covid vaccine.

44:52

So we talked to our, the person down

44:54

and where the scans were done

44:56

and the techs actually called the patients up

44:58

and it turns out they both had covid vaccines about four

45:01

weeks before they had the mr.

45:03

So again, this was due to a,

45:04

a covid related brachial plexopathy.

45:07

It's not necessarily injuring the brachial plexus,

45:10

but as we all know, you can have a pretty robust

45:12

inflammatory response.

45:14

I don't wanna say it's a complication,

45:16

but it is associated with the covid vaccine.

45:20

So the last thing that I'm gonna leave you with is that,

45:23

you know, when I started doing brachial plexus imaging years

45:25

ago, um,

45:29

it really is based on anatomy.

45:31

I think the the take home message is

45:33

you've gotta learn the anatomy.

45:35

But one thing that I have seen over time, um,

45:38

and especially in you know, the

45:39

with the group I'm in right now is that there's a lot

45:42

of cases where we under call brachial neuropathy

45:45

and it's due to a brachial neuritis.

45:47

And this is really due to the technique that you use.

45:52

So whenever you get into your practice

45:55

or if you have the ability to control this,

45:57

it's really important to optimize the sequences that you use

46:01

for the brachial plexus, especially the T two

46:04

slash stir sequences.

46:06

So if you don't, then you're going to start

46:10

to miss various types of viral neuritis.

46:13

So this is an example here of this black blood technique

46:17

and you can see how you really have beautiful visualization

46:20

here of the brachial plexus.

46:22

And once you start having this degree of clarity

46:25

of the brachial plexus,

46:27

you're now gonna start picking up pathology

46:29

that you never did see.

46:31

So this was a patient

46:32

that actually had an idiopathic neuropathy involving

46:35

the brachial plexus.

46:36

So when we look at the right side here,

46:38

we can see diffuse thickening

46:40

and increased signal involving the right brachial

46:43

plexus compared to the left.

46:45

And this is a standard anatomic image right here in a

46:48

patient that had a right side of brachial plexopathy.

46:50

We can see that the subclavian artery

46:52

looks stone cold normal.

46:54

We see that the brachial plexus itself doesn't look thicken

46:58

when we actually do do the, uh, the,

47:02

the heavily the, excuse me,

47:04

when we do do the fat suppressed images

47:06

and the stir sequences,

47:07

notice the yellow arrows right here pointed asymmetrical,

47:10

increased signal involving the right brachial plexus

47:14

and this was due to an adhesive

47:15

capsulitis involving shoulder.

47:17

So if you didn't do this type of technique

47:20

and you only relied on the standard anatomic image,

47:23

you really wouldn't be able to make that diagnosis

47:25

because you don't see anything compressive.

47:28

But the key thing is, is that if you do this type

47:31

of sequences, then you'll be able

47:33

to identify actual different types

47:35

of neuritis involving the brachial plexus.

47:40

And just the one last thing I'll do,

47:41

it's not a musculoskeletal image, uh, it's or or talk,

47:45

but there is one type of viral neuropathy

47:47

that can actually result in weakness of the shoulder girdle.

47:51

And this is the parsonage turner syndrome.

47:54

So parsonage turner syndrome is a viral neuritis

47:57

that typically involve multiple nerve roots,

47:59

these nerve roots form to combine the brachial plexus.

48:02

And then what ends up happening is essentially you have in a

48:05

way an inflammatory process

48:07

that results in an acute denervation atrophy

48:11

or I should say denervation changes in the muscle.

48:14

And here we can see abnormal enhancement involving the

48:17

muscle girdle that is we received is innervation from the

48:20

brachial plexus and this is the parsonage turner syndrome.

48:25

So in summary, what we did is that we went over the anatomy.

48:29

So what are my take home points for you?

48:32

It's anterior scaling, middle scaling subclavian artery.

48:36

So I really encourage you that

48:37

after this lecture is just go look your cervical spine, CTS

48:41

and MR and look for these three structures.

48:44

If you do this 20 times,

48:46

you'll never forget the brachial plexus.

48:49

I guarantee you're always gonna be able to see it.

48:52

We talked about traumatic cases,

48:54

we talked about various types of neoplasms.

48:57

Remember nerve sheath versus non nerve sheath,

48:58

the nine versus malignant

49:00

and then we ended up with inflammatory process.

49:03

And also kind of emphasizing now

49:05

that if you do your technique just right, you'll be able

49:08

to pick up some of these neuropathies

49:11

that sometimes are very difficult to see.

49:13

So thank you very much for your attention

49:15

and I'm happy to answer any questions.

49:21

Thank you. I do have a question.

49:23

Um, okay, so do you also see degeneration injury like in the

49:28

muscles in the other etiologies or only in parsonage turner?

49:33

Uh, so say that, ask the question one more time.

49:36

I wanna make sure I understand it.

49:38

So do you see for example like so muscle edema

49:41

or signal changes in muscles inated by the bural plexus

49:46

with the other etiologies as well

49:49

or only in the viral etiology?

49:52

Uh, it's a good question. Um, to be honest with you,

49:56

I don't know if I have an

49:57

experience to answer that question.

49:59

'cause oftentimes I stop right here

50:01

and I don't have enough information to look at the muscles.

50:04

My sense is is that you can see it in other etiologies.

50:08

Um, and to be honest with you,

50:09

I added Parsons Turner syndrome

50:11

because I always forget about it.

50:13

So I always have to remind myself.

50:15

So to be honest with you, I don't know,

50:16

but I think I have seen cases

50:18

where I've seen muscle enhancement that were not due

50:21

to Parsons Turner syndrome.

50:22

So I think sometimes it just can be due to regular trauma,

50:25

um, or maybe an occasionally idiopathic process

50:28

that's not the classic parsonage turner.

50:32

Remember one thing that I had learned too is

50:34

that when we talk about things, I know Andre,

50:37

you were on the talk earlier today.

50:39

Oh by the way it's perceval pots.

50:41

So remember pots puffy tube, it's perceval pots.

50:44

So I now I remember the name an hour later.

50:46

That's the way my mind works. It's a bit of a delay.

50:48

But where I'm going with this is that if you have like pots,

50:51

puffy tumor and parsonage turner syndrome

50:55

and grad nego syndrome

50:56

and Darrell's canal, these were all named long

51:00

before the days of CT and mr.

51:03

So parsonage turner syndrome is not necessarily a

51:06

radiological disease, it's a clinical syndrome

51:09

where people cannot raise their shoulder.

51:12

So when you talk about the syndrome,

51:13

we're really talking about the end result of this

51:16

and then we see the imaging findings that are associated

51:19

with the classic syndrome.

51:20

So you probably can see muscle enhancement

51:23

that are not quote unquote parsonage turner syndrome

51:26

because the syndrome has to be the classic syndrome

51:28

that was described years ago.

51:30

So that's a long answer to say yeah, probably, probably not.

51:35

Um, you can see with other etiologies.

51:38

But I did wanna emphasize that some of the names

51:40

that you see are not based on imaging.

51:42

There's actually based on when they were described,

51:45

oftentimes now over a hundred years ago.

51:52

I have a question. Um, am I off mute? Yeah.

51:56

Is there a role for Mr. Neurography for the brachial plexus?

52:01

So yeah, it depends on what you define as Mr. Neurography.

52:05

I kind of purposely avoided that term,

52:06

but I'm glad you asked it.

52:08

So the question is what is Neurography?

52:10

To me Neurography is imaging of the cranial nerves,

52:13

or excuse me, imaging of any nerves.

52:15

And so, you know, for me,

52:17

I've been imaging nerves back since the last century.

52:19

Back in the nineties. I remember when I started my

52:21

fellowship we were actually looking

52:22

for perineural enhancement.

52:24

You know, is that Mr. Neurography?

52:26

You know, I don't know the whole term of Mr.

52:29

Neurography was sort of coined in the late nineties

52:32

when a group out in Washington came out with these kind

52:35

of dedicated coils and they started looking at the nerves.

52:38

Ever since then there's been this, you know,

52:41

interest in quote unquote neurography.

52:43

You know, I'm editor of uh,

52:45

both neuroimaging clinics and MR clinics.

52:47

So we've actually had issues dedicated to neurography.

52:51

When you actually look at the content, some

52:53

of those are cranial nerves, some

52:54

of those are brachial plexus, some to me Mr.

52:57

Neurography is the ability of MR to identify nerves.

53:00

Now once you start doing these stir sequences

53:03

and the neural view sequences

53:04

and you really focus on the nerves, that sort of is Mr.

53:08

Neurography at the next level. But for me, Mr.

53:11

Neurography is optimizing your sequences to

53:15

look at nerves anywhere in the body.

53:19

Yeah. Thank you.

53:30

Anything else? I had a question. Sure.

53:33

For a radia radiation associated plexopathy mm-hmm.

53:38

What is the average timeline that you've come across

53:43

for the symptoms to occur?

53:45

Yeah, it's great question.

53:47

I think I actually have another talk.

53:48

I wanna say it's probably about six months

53:50

to a year I believe.

53:52

Um, now when you first give the radiation therapy,

53:54

you can have an acute response,

53:56

but um, in general it takes a while in order

53:59

to develop the fibrosis.

54:00

So you have this longstanding ischemia

54:02

that develops in fibrosis.

54:04

So I think in general it's about six months to a year.

54:07

So if I see someone that presents

54:08

with pain within three months

54:09

and I really start, do worry about metastases,

54:12

but if it occurs, um, two, three years later

54:15

and I know they've had high dose

54:16

and oftentimes it's due to the fibrosis.

54:18

So that, that's sort of my rule of thumb for that.

54:22

That's a good question.

54:32

Anything else? We've got a couple more minutes.

54:36

Mm-Hmm, that's okay.

54:38

So what are uh, special sequences that, uh, we would,

54:42

we should incorporate in our routine o brachial plexus, MRI

54:47

or like what there is, we take OBL along the planes

54:52

that is T two, we take a Corona stir

54:56

and we usually take a fiesta.

54:58

But is it really helpful

54:59

because we don't really appreciate the

55:04

individual nerves quite well on those sequences?

55:09

Yeah, I think you're right on.

55:10

I don't, I'm not a huge fiesta fan.

55:12

Sort of are kind of cute sequences

55:14

'cause you can see the nerves and they make great pictures,

55:17

but it really doesn't tell you the signal abnormality and

55:20

because it doesn't have the ability to differentiate

55:23

between the fat and the muscle and so on and so forth.

55:26

I'm not really sure how helpful the fiestas are.

55:29

I think the fiesta are great for cranial nerves.

55:31

Um, I think the coronal t twos and the stirs are good.

55:35

Um, to me they're a little bit redundant.

55:38

Um, I think if you use one

55:40

you probably don't need the other.

55:41

Um, but whatever you do, you know, I would certainly, uh,

55:45

you know, I would certainly, if you have the capability is

55:49

to work with your team to optimize the sequences, uh,

55:52

in order to try to reduce your background fat

55:56

and try to optimize the enhancement here of the nerve.

55:58

So at least one coronal sequence like

56:01

that I think is really, really good to me.

56:04

The majority of the times, you know,

56:05

I still like the good old standard T one

56:07

and t twos with, with contrast and so on and so forth.

56:11

But I have over time become very reliant on

56:14

the sequence as well too.

56:17

But yeah, I'd probably get rid of the fiestas too.

56:21

All right, well you guys, guys have a,

56:23

in the US it's gonna be Thanksgiving, so, you know,

56:26

happy Thanksgiving to you

56:28

and, uh, happy Thanksgiving, I think.

56:30

Yeah, I think I'll see you guys in exactly two weeks

56:33

because then we'll have a two hour session

56:35

to go over the last two weeks of the fellowship.

56:38

And if you need me, you can always, um,

56:39

reach out to me or something like that.

56:41

And I'm glad you guys were able

56:42

to make the extra lectures too.

56:44

So, um, if something else comes up, I'll,

56:46

uh, I'll, I'll let you know.

56:48

Thank you Dr. mcc, everyone have a great day.

56:52

Bye.