0:00

This patient presented with a palpable

0:02

mass involving the left clavicle, and also

0:06

presented with left brachial plexopathy.

0:08

So, when we look at these images on

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the non-contrast axial T1-weighted

0:12

image, what we see is this mass right

0:14

here, which is involved in the clavicle.

0:16

And we can also see there's abnormal replacement

0:19

involving the, what we should see is a typically

0:21

high T1 signal involved in the clavicle.

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So, we know that there's a mass there.

0:27

The purpose of this mastery course,

0:29

is to identify how do we know that

0:31

it's involving the brachial plexus.

0:33

So yes, this mass is pretty easy to see,

0:36

but really, let's take it to the next level.

0:38

So, when we start looking at the brachial

0:39

plexus, again, we have to look for

0:41

those three primary anatomic components:

0:44

The anterior scalene, the middle

0:45

scalene, and the subclavian artery.

0:48

So on this image, if I draw my line down the

0:50

middle, and again, I compare one side to the

0:53

opposite side, what I see here is the anterior

0:56

scalene muscle, which is here, right here.

0:58

And then I can see the posterior

0:59

scalene muscle, which is here.

1:01

And then I can see the brachial plexus

1:04

extending through the plane of the

1:05

anterior and the middle scalene muscles.

1:08

Now, on the side of the abnormality,

1:10

I can see the anterior scalene here.

1:13

I can see the middle scalene here.

1:15

And then what I can see now, it jumps

1:17

out at you, are the supraclavicular

1:20

components of the brachial plexus

1:22

extending through those two muscles.

1:25

So, the brachial plexus is actually

1:27

pretty easy to see once you can

1:28

identify where it should be located.

1:31

And now what we can do is that we can follow

1:33

this brachial plexus out laterally and we

1:36

can see that this mass is actually abutting

1:39

the proximal cords of the brachial plexus.

1:42

So that's why the patient's having

1:43

the brachial plexus symptoms.

1:45

On the middle image here, which is

1:47

a fat-suppressed T1-weighted type of

1:49

sequence, we can see the mass right

1:51

here, which is involved in the clavicle.

1:53

And again, what we have to do is

1:55

try to find that subclavian artery.

1:58

Well, here's our subclavian artery

1:59

right here, which I'm drawing it.

2:01

And right above it are the

2:03

cords of the brachial plexus.

2:05

Remember, every time you find that

2:07

subclavian artery, the cords of the

2:08

brachial plexus lay right on top of it.

2:11

So we can easily see the cords, and if we follow

2:14

it immediately, we can see that the cords of

2:16

the brachial plexus are actually compressed by

2:19

this mass right here involving the clavicle.

2:22

So we can see that inferior component of

2:24

the mass is abutting the superior portion

2:27

of the cords of the brachial plexus.

2:29

So again, that's the involvement

2:31

of that brachial plexus.

2:33

And then when we look at the fat-

2:34

suppressed T2-weighted imaging, we

2:35

see another interesting finding.

2:38

So here, again, is this

2:39

mass involving the clavicle.

2:40

We can see the abnormal marrow

2:42

within the clavicle, and we can

2:45

see the mass extending deeply.

2:47

Now, on the patient's right-hand side, here's

2:50

the anterior scalene, and here's the posterior

2:52

scalene, and right here is the brachial plexus

2:56

extending into the plane of those two muscles.

2:59

And what we see here on the left

3:00

hand side is there's actually

3:02

abnormal signal in the clavicle,

3:04

involving the brachial plexus.

3:06

So here's the anterior scalene muscle,

3:08

here's the middle scalene muscle, and you

3:10

can see that this mass is not only abutting,

3:14

but it's actually resulting in edema

3:17

involving the supraclavicular components

3:20

of the brachial plexus as they start to

3:22

form the cords of the brachial plexus.

3:24

So in this particular case,

3:25

this turned out to be lymphoma.

3:27

The lymphoma was involving the brachial plexus.

3:30

And not only was it resulting in mass effect of

3:32

the brachial plexus, but it was actually causing

3:34

edema of the brachial plexus, which is best

3:37

seen on the fat-suppressed T2-weighted images.