Lea Alhilali, MD Profile picture
May 16, 2023 14 tweets 6 min read Read on X
1/Do you want a BASIC approach to skullBASE lesions?

My FINAL tweetorial on skullbase lesions—posterior skullbase & overall approach!

This #tweetorial will teach you to diagnose skullbase lesions by answering only TWO simple questions!

#medtwitter #meded #neurosurgery #radres Image
2/Remember, you can think of pathology at the skullbase like bad things that can happen while running. Bad things can get you from below—like falling into a pothole. They can come from within—like a sudden heart attack, or bad things can strike from above, like a lightning bolt Image
3/Same thing w/the skullbase—bad things can come from below, within, or above. Lesions from below are potholes tripping you up. Lesions from w/in the skullbase are like heart attacks strikning from inside. Lesions from above are the lightning, hitting the skullbase from above Image
4/So what lesions come from below, within, or above? This is determined by what tissues live there. Think of the skullbase like a sandwich. Bones of the skullbase are the filling, sandwich between the bread of the sinonasal cavity & intracranial contents Image
5/But it also matters where a lesion involves the skullbase. The different regions of the skullbase are very different, like different countries. Just like different countries have their own culture & traditions, these different skullbase regions of have their own typical tumors Image
6/Countries grew different cuisines based on what was plentiful in their area. Like tomatoes grew well in Italy but not England, so Italy has more tomato-based dishes. Same w/the skullbase regions--they have different tumors depending on what tissues are plentiful in their area Image
7/We’ve previously reviewed anterior & central skullbase. I think the posterior skullbase looks like the circle of the Greek isles. You can remember pathology in this area by thinking Greek! Image
8/For lesions from below, a unique lesion to the posterior skullbase is paragangliomas, glomus jugulare. It classically has a salt & pepper appearance because of the T2 hyperintense stroma (salt) & dark flow voids (pepper), but bc it’s Greek, let’s call it a Tzatziki appearance Image
9/For lesions from within, there are no specific lesions—just lesions that are not unique to the skullbase that tend to involve marrow/bones, such as mets/myeloma, Paget’s, etc. But remember, these lesions tend to be multiple—just like there are multiple Greek isles! Image
10/Lesions from above come from the intracranial contents abutting the skullbase (dura & cranial nerves). Lower CNs at the posterior skullbase commonly form schwannomas. Remember this bc Greek gyros are basically made w/shawarma meat, & these "shawarmomas" look like little gyros Image
11/These schwannomas can become very large—then I think they look like overloaded gyros! Image
12/So for every skullbase lesions, you should ask yourself 2 questions:

Which regions is it located? (anterior, central or posterior)

& Where is it arising from? (from below, from within, or from above) Image
13/The intersection of the answer to these two questions will narrow your differential in this very complex region to only a few entities—possibly even a single entity! Image
14/So remember, the skullbase may have many parts, many tissues, and many pathologies, but you only need to answer 2 questions to get you to the correct answer! Image

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Jul 2
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Does medullary anatomy send you into respiratory arrest?

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Everything going down into the cord must pass through the medulla & everything from the cord going back up to the brain must too.

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Never fear—here is a thread on all the incomplete spinal cord syndromes to get you moving again! Image
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1/Do you get a Broca’s aphasia trying remember the location of Broca's area?

Does trying to remember inferior frontal gyrus anatomy leave you speechless?

Don't be at a loss for words when it comes to Broca's area

Here’s a 🧵to help you remember the anatomy of this key region! Image
2/Anatomy of the inferior frontal gyrus (IFG) is best seen on the sagittal images, where it looks like the McDonald’s arches.

So, to find this area on MR, I open the sagittal images & scroll until I see the arches. When it comes to this method of finding the IFG, i’m lovin it. Image
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1/Feeling intoxicated trying to remember all the findings in alcohol use disorder?!

Here’s something to put you in high spirits!

This month’s @Radiographics has the important neuroimaging findings alcohol use disorder!



@cookyscan1 @RadG_editor #RGphx pubs.rsna.org/doi/10.1148/rg…Image
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“Basal ganglia is white...”

Get intrinsic T1 shortening in the BG that makes it look white as a ghost! Image
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1/Need help reading spine imaging? I’ve got your back!

It’s as easy as ABC!

A thread about an easy mnemonic you can use on every single spine study you see to increase your speed & make sure you never miss a thing! Image
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Look for:
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On CT, the most important thing to look for w/bones is fractures. You may see focal bony lesions, but you may not

On MR, it is the opposite—you can see marrow lesions easily but you may or may not see edema associated w/fractures if the fracture is subtle Image
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