Lea Alhilali, MD Profile picture
Nov 21, 2022 17 tweets 8 min read Read on X
1/Ready for a throwdown? MMA fights get a lot of attention, but MMA (middle meningeal art) & dural blood supply doesn’t get the attention it deserves.

A #tweetorial on dural vascular #anatomy

#neurosurgery #neurorad #Neurointervention #radres #medtwitter #neurotwitter #meded Image
2/Everyone knows about the blood supply to the brain. Circle of Willis anatomy is king and loved by everyone, while the vascular anatomy of the blood supply to the dura is the poor, wicked step child of vascular anatomy that is often forgotten Image
3/But dural vascular anatomy & supply are important, especially now that MMA embolizations are common for chronic recurrent subdurals. It also important for understanding dural arteriovenous fistulas as well. Image
4/Although we talk about individual vessels feeding the dura, it should actually be thought of more as a vascular network. Anastomoses among the dural vessels are common and plentiful, as is often seen with external carotid networks. Image
5/The largest & most important dural vessel is the middle meningeal artery or MMA. It arises from the internal maxillary artery or IMAX. I remember that b/c Mortal Kombat & other MMA type fighting is commonly shown in IMAX theaters. Image
6/MMA enters at foramen spinosum.

At the skullbase, foramen ovale & spinosum together look like a high heel shoe footprint

Spinosum is the heel of the footprint. I remember this b/c that’s the high heel spike and SPinosum & SPike sound alike. I always look for this footprint Image
7/After spinosum, the MMA takes a sharp, corkscrew-like turn lateral & anterior following the curvature of the middle cranial fossa.

This gives it a very characteristic angiographic appearance—always look for the sharp turn.

I remember that the artery SPINs after SPINosum Image
8/MMA immediately gives off a tiny petrous branch and then splits into anterior (frontal) & posterior (parietal) divisions. I think it looks like an MMA fighter celebrating their victory with their two arms in the air Image
9/Post division is smaller & has branches covering the posterior convexity. Its territory is draped over the back of the calvarium the way MMA fighters drape flags over their backs after winning. So it covers the back of the calvarium like the flag covers the MMA fighter’s back Image
10/Ant division is larger & has branches that anastomose to the contralateral MMA. You can remember this b/c opposing MMA fighters touch gloves before the fight, and gloves are out in front. So ant division touches the opposite side like opponents touching gloves before a fight Image
11/Anterior division passes under the pterion, a junction of four calvarial bones. This renders it vulnerable to trauma & resulting epidural hemorrhage. This is easy to remember—the forward facing or anterior part of an MMA fighter (his face) is very vulnerable to injury Image
12/Posterior meningeal artery is much smaller than the MMA. It arises from the ascending pharyngeal artery and supplies the dura to the posterior fossa. It also has anastomoses with the posterior division of the MMA. Image
13/You can remember its origin bc TONSILS are in the PHARYNX, so the ascending PHARYNGEAL supplies the dural around the cerebellar TONSILS (posterior fossa) Image
14/Anterior meningeal artery is also much smaller than the MMA. It arises from both the anterior and posterior ethmoidal arteries. It supplies the dura of the anterior cranial fossa. It has many anastomoses with the frontal branches of the MMA Image
15/You can remember its origin bc the anterior meningeal artery supplies the dura overlying the ethmoids, so it would make sense it arises from the ethmoidal arteries Image
16/Uniquely, as it ascends, the anterior meningeal artery actually runs in the wall of the anterior superior sagittal sinus. It is the only named artery to run in the wall of a sinus. Image
17/Now you know the anatomy of the major arterial supply to the dura & their territories. So the next time someone questions you about dural blood supply, you can attack it MMA style! Image

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Lea Alhilali, MD

Lea Alhilali, MD Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @teachplaygrub

Mar 3
1/Does PTERYGOPALATINE FOSSA anatomy feel as confusing as its spelling?

Does it seem to have as many openings as letters in its name?

Are you pterrified of the pterygopalatine fossa (PPF)?

Let this thread on PPF anatomy help you out. Image
2/The PPF is a crossroads between the skullbase & the extracranial head and neck

There are 4 main regions that meet here:

(1) Skullbase itself posteriorly, (2) nasal cavity medially, (3) infratemporal fossa laterally, and (4) orbit anteriorly. Image
3/At its most basic, you can think of the PPF as a room with 4 doors opening to each of these regions: one posteriorly to the skullbase, one medially to the nasal cavity, one laterally to the infratemporal fossa, and one anteriorly to the orbit Image
Read 18 tweets
Feb 28
1/Feel like a fish out of water when it comes to water on the brain?

Read on for this month’s @Radiographics summary of what you need to know about hydrocephalus!!



@cookyscan1 @RadG_editor #RGphx doi.org/10.1148/rg.240…Image
2/To understand hydrocephalus, think of CSF like the flow of traffic

3 main ways traffic backs up:

(1) Obstruction on the road:
For hydrocephalus, this is an obstruction along CSF in the ventricle Image
3/

(2) Obstruction of an off ramp
For hydrocephalus=obstruction at its off ramp into the venous system

(3) Rush hour
For hydrocephalus=over production Image
Read 8 tweets
Feb 27
1/Do scans for dizziness make your head spin?

Need to know what to look for?

Just hear me out!

This month’s @theAJNR SCANtastic will show what to look for:

ajnr.org/content/46/2/3…Image
2/I always remember the rhyme of the big three for dizz-ee!

First, are vestibular schwannomas

These give an ice cream cone shape in the internal auditory canal! So scoop up that finding! Image
3/Next is labyrinthitis

Labyrinthitis can look like night & day, depending on the timing

Late labyrinthitis is dark—loss of bright fluid signal on FIESTA

Early labyrinthitis is bright—enhances on post-contrast Image
Read 12 tweets
Feb 26
1/Time is brain! But what time is it?

If you don’t know the time of stroke onset, are you able to deduce it from imaging?

Here’s a thread to help you date a stroke on MRI! Image
2/Strokes evolve, or grow old, the same way people evolve or grow old

The appearance of stroke on imaging mirrors the life stages of a person—you just have to change days for a stroke into years for a person

So 15 day old stroke has features of a 15 year old person, etc. Image
3/Initially (less than 4-6 hrs), the only finding is restriction (brightness) on diffusion imaging (DWI)

You can remember this bc in the first few months, a baby does nothing but be swaddled or restricted

So early/newly born stroke is like a baby, only restricted Image
Read 10 tweets
Feb 25
1/My hardest thread yet! Are you up for the challenge?

How stroke perfusion imaging works!

Ever wonder why it’s Tmax & not Tmin?

Do you not question & let RAPID read the perfusion for you? Not anymore! Image
2/Perfusion imaging is based on one principle: When you inject CT or MR intravenous contrast, the contrast flows w/blood & so contrast can be a surrogate marker for blood.

This is key, b/c we can track contrast—it changes CT density or MR signal so we can see where it goes. Image
3/So if we can track how contrast gets to the tissue (by changes in CT density or MR signal), then we can approximate how BLOOD is getting to the tissue.

And how much blood is getting to the tissue is what perfusion imaging is all about. Image
Read 18 tweets
Feb 24
1/”That’s a ninja turtle looking at me!” I exclaimed. My fellow rolled his eyes at me, “Why do I feel I’m going to see this a thread on this soon…”

He was right! A thread about one of my favorite imaging findings & pathology behind it Image
2/Now the ninja turtle isn’t an actual sign—yet!

But I am hoping to make it go viral as one. To understand what this ninja turtle is, you have to know the anatomy.

I have always thought the medulla looks like a 3 leaf clover in this region.

The most medial bump of the clover is the medullary pyramid (motor fibers).

Next to it is the inferior olivary nucleus (ION), & finally, the last largest leaf is the inferior cerebellar peduncle.

Now you can see that the ninja turtle eyes correspond to the ION.Image
3/But why are IONs large & bright in our ninja turtle?

This is hypertrophic olivary degeneration.

It is how ION degenerates when input to it is disrupted. Input to ION comes from a circuit called the triangle of Guillain & Mollaret—which sounds like a fine French wine label! Image
Read 9 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us!

:(