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So this was a patient that presented

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with left brachial neuritis.

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So clinically, they had pain extending along the

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expected innervation of the brachial plexus.

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So the reason why we show this particular

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case is to emphasize the importance of doing

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some type of sequence that is optimized to

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look at the signal within the nerve sheath.

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It can be some type of STIR

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sequence or heavily T2-weighted

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sequence with fat suppression.

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Whatever your vendor has or whatever

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you have on your system, but it is

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important to optimize those sequences.

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So, on the left-hand side, again, we

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see a coronal T1-weighted image, and

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again, the first thing that I always do

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is I try to find the brachial plexus.

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So, instead of trying to hunt for the

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brachial plexus, what I do is I always

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try to find that subclavian artery.

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So, when I find the subclavian artery,

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then I can look for the cords of the

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brachial plexus, which you can see here.

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My arrow points at them adjacent

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to the subclavian artery.

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

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subclavian artery on the right, and we

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can see the cords of the brachial plexus

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directly adjacent to that subclavian artery.

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So, this patient has left-sided symptoms,

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but when we look at our standard

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sequences, we do not see any compressive

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mass involving the brachial plexus.

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But when we look at this STIR sequence,

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now what we see is that we see this abnormal

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signal involving the brachial plexus on

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the left that's not there on the right.

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So, in fact, when we look at the right-hand

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side, we almost see a signal void between

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these two cords of the brachial plexus.

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But on the left-hand side, we can

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see this whole cord is asymmetrically

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with higher increased signal, and this

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correlates with the patient's symptoms.

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So, this is an example of probably a viral

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neuritis involving the brachial plexus.

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Sometimes it's actually hard to figure

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out exactly what causes it, but when

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you do have the onset of pain without

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any evidence of history of trauma, any

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history of radiation therapy, etc., we

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often just assume that it's due to a

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viral neuritis involving the brachial plexus.