Lea Alhilali, MD Profile picture
Neuroradiologist @HRInstitute_AZ. @BarrowNeuro. Striving to make learning neuroimaging and anatomy fun. If I can make you laugh, I can make you learn.
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Jul 29 9 tweets 4 min read
1/Talk about bad blood!

Do you know when a hematoma is going to expand?

Read on for month’s @theAJNR SCANtastic on all you need to know about imaging intracranial hemorrhage!

ajnr.org/content/46/7/1…Image @TheAJNR 2/Everyone knows about the spot sign for intracranial hemorrhage

It’s when arterial contrast is seen within a hematoma on CTA, indicating active
extravasation of contrast into the hematoma.

But what if you want to know before the CTA? Image
Jul 25 10 tweets 4 min read
1/Time to go with the flow!

Hoping no one notices you don’t know the anatomy of internal carotid (ICA)?

Do you say “carotid siphon” & hope no one asks for more detail?

Here’s a thread to help you siphon off some information about ICA anatomy! Image 2/ICA is like a staircase—winding up through important anatomic regions like a staircase winding up to each floor Lobby is the neck.

First floor is skullbase/carotid canal. Next it stops at the cavernous sinus, before finally reaching the rooftop balcony of the intradural space.Image
Jul 23 18 tweets 7 min read
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
Jul 21 12 tweets 5 min read
1/Do you know all the aspects of, well, ASPECTS?

Many know the anterior circulation stroke scoring system—but posterior circulation (pc) ASPECTS is often left behind

25% of infarcts are posterior circulation

Do you know pc-ASPECTS?!

Here’s how to remember pc-ASPECTS! Image 2/Many know anterior circulation ASPECTS.

It uses a 10-point scoring system to semi-quantitation the amount of the MCA territory infarcted on non-contrast head CT

If you need a review: here’s my thread on ASPECTS: Image
Jul 2 18 tweets 7 min read
1/The medulla is anything but DULL!

Does seeing an infarct in the medulla cause your heart to skip a beat?

Does medullary anatomy send you into respiratory arrest?

Never fear, here is a thread on the major medullary syndromes! Image 2/The medulla is like a toll road.

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

That’s a lot of tracts for a very small territory. Luckily you don’t need to know every tract Image
Jun 30 10 tweets 4 min read
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
Jun 27 20 tweets 8 min read
1/”I LOVE spinal cord syndromes!” is a phrase that has NEVER, EVER been said by anyone.

Do you become paralyzed when you see cord signal abnormality?

Never fear—here is a thread on all the incomplete spinal cord syndromes to get you moving again! Image 2/Spinal cord anatomy can be complex. On imaging, we can see the ant & post nerve roots. We can also see the gray & white matter. Hidden w/in the white matter, however, are numerous efferent & afferent tracts—enough to make your head spin. Image
Jun 23 13 tweets 5 min read
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
Jun 19 8 tweets 3 min read
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 2/There’s an easy rhyme to help you remember the important neuroimaging findings of alcohol use disorder

“Basal ganglia is white...”

Get intrinsic T1 shortening in the BG that makes it look white as a ghost! Image
Jun 9 11 tweets 5 min read
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 2/A is for alignment

Look for:
(1) Unstable injuries

(2) Malalignment that causes early degenerative change. Abnormal motion causes spinal elements to abnormally move against each other, like grinding teeth wears down teeth—this wears down the spine Image
Jun 6 20 tweets 8 min read
1/Raise your hand if you’re confused by the BRACHIAL PLEXUS!

I could never seem to remember or understand it—but now I do & I’ll show you how!

A thread so you will never fear brachial plexus anatomy again! Image 2/Everyone has a mnemonic to remember brachial plexus anatomy.

I’m a radiologist, so I remember one about Rad Techs.

But just remembering the names & their order isn’t enough.

That is just the starting point--let’s really understand it Image
Jun 4 20 tweets 8 min read
1/Having trouble remembering what to look for in vascular dementia on imaging?

Almost everyone w/memory loss has infarcts. Which are important?

The latest @theajnr SCANtastic has what you need to know:

ajnr.org/content/46/5/1…Image @TheAJNR 2/Vascular cognitive impairment, or its most serious form, vascular dementia, used to be called multi-infarct dementia.

It was thought dementia directly resulted from brain volume loss from infarcts, w/the thought that 50-100cc of infarcted related volume loss caused dementia Image
Jun 2 16 tweets 6 min read
1/Having trouble remembering how to differentiate dementias on imaging?

Is looking at dementia PET scans one of your PET peeves?

Here’s a thread to show you how to remember the imaging findings in dementia & never forget! Image 2/The most common functional imaging used in dementia is FDG PET. And the most common dementia is Alzheimer’s disease (AD).

On PET, AD demonstrates a typical Nike swoosh pattern—with decreased metabolism in the parietal & temporal regions Image
May 27 12 tweets 5 min read
1/Feel perplexed by the lumbosacral plexus??

This plexus doesn’t have to be so complex-us

Here’s what you need to know from this month’s @Radiographics!



@cookyscan1 @RadG_editor doi.org/10.1148/rg.240…Image @RadioGraphics @cookyscan1 @RadG_Editor 2/The lumbosacral plexus is like a love story

The lumbar & sacral plexuses met & fell in love

They loved each other so much they came together to create the nerves to the lower extremities! Image
May 6 16 tweets 7 min read
1/Have disagreements between radiologists on the degree of cervical canal stenosis become a pain in the neck?

Worried about sticking your neck out & calling severe cervical stenosis?

This month’s @theAJNR SCANtastic has the latest about Cspine MRI!

ajnr.org/content/46/4/7…Image @TheAJNR 2/In the lumbar spine, it is all about the degree of canal narrowing & room for nerve roots.

In the cervical spine, we have another factor to think about—the cord.

Cord integrity is key. No matter the degree of stenosis, if the cord isn’t happy, the patient won’t be either Image
May 2 20 tweets 8 min read
1/Do radiologists sound like they are speaking a different language when they talk about MRI?

T1 shortening what? T2 prolongation who?

Here’s a translation w/an introductory thread to MRI. Image 2/Let’s start w/T1—it is #1 after all! T1 is for anatomy

Since it’s anatomic, brain structures will reflect the same color as real life

So gray matter is gray on T1 & white matter is white on T1

So if you see an image where gray is gray & white is white—you know it’s a T1 Image
Apr 28 20 tweets 8 min read
1/Asking “How old are you?” can be dicey—both in real life & on MRI! Do you know how to tell the age of blood on MRI?

Here’s a thread on how to date blood on MRI so that the next time you see a hemorrhage, your guess on when it happened will always be in the right vein! Image 2/If you ask someone how to date blood on MRI, they’ll spit out a crazy mnemonic about babies that tells you what signal blood should be on T1 & T2 imaging by age.

But mnemonics are crutch—they help you memorize, but not understand. If you understand, you don’t need to memorizeImage
Apr 25 20 tweets 7 min read
1/Radiologist not answering the phone?

Just want a quick read on that stat head CT?

Here's a little help on how to do it yourself w/a thread on how to read a head CT! Image 2/In bread & butter neuroimaging—CT is the bread—maybe a little bland, not super exciting—but necessary & you can get a lot of nutrition out of it

MRI is like the butter—everyone loves it, it makes everything better, & it packs a lot of calories. Today, we start w/the bread! Image
Apr 23 19 tweets 7 min read
1/Time to FESS up! Do you understand functional endoscopic sinus surgery (FESS)?

If you read sinus CTs, you better know what the surgeon is doing or you won’t know what you’re doing!

Here’s a thread to make sure you always make the important findings! Image 2/The first step is to insert the endoscope into the nasal cavity.

The first two structures encountered are the nasal septum and the inferior turbinate. Image
Apr 21 17 tweets 6 min read
1/Ready for a throw down?

MMA fights get a lot of attention, but MMA (middle meningeal art) & dural blood supply doesn’t get the attention it deserves.

A thread on dural vascular anatomy! 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
Apr 16 9 tweets 3 min read
1/ Need a global perspective on dementia?

Do you know the global cortical atrophy (GCA) score for evaluating dementia patients—or are you still gestalting volume loss???

Don’t estimate when you can calculate!

Here’s a thread of what you need to know about the GCA score! Image 2/The global cortical atrophy score calculates cortical volume loss on a scale of 0-3 in 13 different regions & ventricular dilatation

Gyri shrink down w/atrophy, the same way your cheeks shrink down with aging! Image