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This patient is 33 years old, he's the man who's

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complaining of right shoulder pain and muscle weakness.

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And we can see axial images on the left,

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these are fat suppressed proton density.

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In the middle we have sagittal stern and on the right

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we have coronal, oblique coronal, T1 weighted images.

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So let's start with the axial images from top to bottom.

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We can see that there is a multiloculated.

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Cystic structure occupying the spinoglenoid notch.

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This structure has a neck that we can

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trace back to the posterior labrum.

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And right at the base of the labrum, posterior

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inferiorly, there is a very clear tear, detachment

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type tear through the base that is communicating

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with this multiloculated cystic mass.

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This is a paralabral cyst some people also call it

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a paralabral ganglion, you can find it by that name.

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The main issue here is that the cyst is in a bad

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location, it's occupying the spinoglenoid notch, and

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that is the area where the suprascapular nerve begins.

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So, we have two areas where the

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suprascapular nerve can get impinged.

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One is right here in the coronal T1 weighted sequence.

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You can see the suprascapular neurovascular bundle.

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This is your scapular neck, and right over the

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scapular neck we have the suprascapular fossa.

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So, if this is to be sitting here, it would be

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compressing the nerve in such a way that both

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the branches that are going to the supraspinatus

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and the infraspinatus would be involved.

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That's not the case.

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The cyst is sitting lower down.

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So as the nerve goes into the spinal

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glenoid notch, right there, that's the cyst.

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On T1 weighted images, it's intermediate signal intensity.

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These cysts usually have high mucin content so they

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are gonna be slightly brighter than just plain fluid.

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And in the spinoglenoid notch, the nerve is being compressed

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and only the infraspinatus muscle branch is involved.

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And that's what you are seeing in the state images, is

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this differential signal intensity in the rotator cuff

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musculature, whereby the infraspinatus muscle is brighter.

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And so, I always say it's almost as if a

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child has taken a colored pencil and has

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colored in the muscle in a brighter shade.

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Supraspinatus right here, you

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can compare the signal intensity.

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And this guy here is the teres minor, which is

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innervated by a different nerve, the axillary nerve.

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So, axillary nerve, teres minor, and these two

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guys are innervated by the suprascapular nerve.

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So, let's go back to the findings.

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We have a posteroinferior labral tear with a paralabral cyst

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multiloculated occupying the spinoglenoid notch resulting

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in denervation edema like change in the infraspinatus

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muscle compatible with suprascapular neuropathy.