Optic Neuritis MRI Advice

[Photonic]

Sorry if I am posting this in the wrong place.

I am trying to get some advice on reading MRIs for optic neuritis.

From my current understanding you would order a T2 FLAIR MRI with and without contrast to best detect optic neuritis. The main thing you would be looking for is increased enhancement of the optic nerve after contrast injection. You cannot recognize optic neuritis based solely on a T2 FLAIR MRI with contrast. Is this correct?

I am asking because upon looking up normal online MRI FLAIR images and comparing them with online MRI FLAIR Images for MS, the intensity of the optic nerve appears equivocal to me. Because of this, I am assuming you distinguish optic neuritis from a normal optic nerve by an increased intensity in images after injecting contrast and not by any individual images.

Any advice or responses are appreciated.

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[maxxor]

Assuming this is not homework help or personal medical questions (your post history indicates you are a medical student):

Optic neuritis is evaluated with an MR of the orbits with and without contrast. The key sequences are the small field of view of the orbits in axial and coronal.

The T1 images are commonly fat saturated to make contrast enhancement more conspicuous. I would personally go for the contrast enhancement of the optic nerve as the key finding to diagnose Optic Neuritis.

T2/Flair images are a CSF suppression sequence that makes white matter lesions more conspicuous. You can see differences in the optic nerves after an event of optic neuritis much like you can see MS plaques.

 

[Cognovi]

T2 FLAIR won't demonstrate contrast enhancement

 

[DeucesHigh3]

T2 FLAIR won't demonstrate contrast enhancement

I thought post-Gd FLAIR was a thing? We don't do it at my institution, but I'm sure I've seen it discussed.

 

[126230]

I thought post-Gd FLAIR was a thing? We don't do it at my institution, but I'm sure I've seen it discussed.

My understanding is that this is done to save time. Instead of waiting around after Gd administration you use that time to acquire a sequence which is not significantly affected by the administration of contrast.

 

[colbgw02]

There is such a thing as T1 FLAIR...it’s good for accentuating the differential T1 signal of grey/white matter.

But when people just say FLAIR, they’re talking about a T2 weighted sequence. Of course, this thread specifically said T2 FLAIR, which ought to avoid any confusion.

There is some literature that post-gad FLAIR will show enhancement that FSE/TSE T1 sequences won’t, but meh .

 

[Cognovi]

Fine I stand corrected. I have not seen post-contrast T2 FLAIR done probably because the signal abnormalities would be confounded by mild contrast enhancement.