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So this is an example of radiation-

0:02

associated brachial plexopathy.

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And this was a patient that ended up having

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a left tonsillar carcinoma that was treated

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with chemotherapy and radiation therapy.

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The patient also had a large metastatic lymph

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node involving the base of the left neck.

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So therefore, there was a fair amount

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of radiation given to the patient.

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in the lower portion of the neck.

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So, when we look at the left image, this

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left image demonstrates the normal appearance

0:29

of the patient's right brachial plexus.

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So, this is C5, this is C6, this

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is C7, this is C8, and this is T1.

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So when we talked about the introductory

0:42

lectures, these were the roots of the

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brachial plexus that eventually form

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the trunks, then they divide, and

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then they form the cords of the brachial

0:50

plexus adjacent to the subclavian artery.

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And you can see a lot of clarity in the

0:56

brachial plexus as these nerves extend from

0:59

the central canal to form the brachial plexus.

1:03

And especially what I want to point out

1:05

is the level of clarity right here

1:07

and the signal intensity involving

1:09

the cords of the brachial plexus.

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Now, on the patient's left hand side,

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notice how there's diffuse thickening

1:16

and swelling of multiple cords of

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the roots of the brachial plexus.

1:21

As we extend laterally, we can see abnormal

1:23

increased signal involving the distal

1:27

trunks and cords of the brachial plexus.

1:29

And what we can also see here is that it's

1:32

almost like they're almost glued together.

1:35

So, the point is, is that what I'm

1:37

trying to differentiate between radiation

1:40

associated brachial plexopathy and

1:43

recurrent tumor, you know, sometimes

1:45

imaging becomes an art versus a science.

1:48

So, if I don't see a specific enhancing

1:51

mass, and we'll show cases of recurrent tumor

1:54

involving the brachial plexus, rather what

1:57

I see here is I see all of the components

2:00

that are thickened, there's increased signal,

2:04

and it's almost like they're glued together

2:06

on the left side compared to the right side.

2:09

Then I start thinking about radiation

2:11

associated brachial plexopathy.

2:14

And on the image on the right hand side, again,

2:16

let's draw our line down the middle, and we

2:19

compare the right side versus the left side.

2:21

Here's our anterior scalene muscle.

2:23

This is the posterior scalene muscle.

2:26

And right here are the cords of the brachial

2:29

plexus involving the right brachial plexus.

2:31

On the left-hand side, here's

2:33

our anterior scalene muscle.

2:35

Here's our middle scalene muscle.

2:37

And right here is the plane of

2:39

those two muscles, and that's

2:41

where the brachial plexus will be.

2:43

So what we can see now is that the

2:45

right-hand side has diffusely enhancing

2:48

and thickened anterior scalene muscle.

2:51

Diffuse thickening and enhancing

2:52

of the posterior scalene muscle.

2:54

And when we actually look at the brachial

2:56

plexus between these two muscles, notice

2:59

the abnormal enhancement of that brachial

3:01

plexus on the left compared to the right.

3:04

So there's no definable mass.

3:06

Rather, what we see here is essentially

3:08

a radiation-induced myositis, if

3:10

you will, because there's diffuse

3:12

thickening enhancing the muscles.

3:14

And we can see the abnormal enhancement

3:16

of the brachial plexus itself.

3:18

So this is an example of radiation-associated

3:22

brachial neuropathy due to inflammation

3:25

of the brachial plexus from the radiation

3:28

therapy given to that specific region.