1/To call it or not to call it? That is the question!

Feeling wacky & wobbly when it comes to normal pressure hydrocephalus?

Don’t want to overcall it, but don’t want to miss it either!

Check out the latest in NPH w/this month’s @theAJNR SCANtastic!

ajnr.org/content/45/10/… 2/NPH was first described in 1965—but, of the original 6 pts, 4 were found to have underlying causes for hydrocephalus.

This begs the question—when do you stop looking & call it idiopathic? When do you suggest it on imaging?

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. 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

1/Time is brain!

So you don’t have time to struggle w/that stroke alert head CT.

If there’s no flow, what are the things you need to know??

Here’s a thread to help you with the five main CT findings in acute stroke. 2/CT in acute stroke has 2 main purposes—(1) exclude intracranial hemorrhage (a contraindication to thrombolysis) & (2) exclude other pathologies mimicking acute stroke.

However, that doesn’t mean you can’t see other findings that can help you diagnosis a stroke.

1/They say form follows function!

Brain MRI anatomy is best understood in terms of both form & function.

Here’s a short thread to help you to remember important functional brain anatomy--so you truly can clinically correlate! 2/Let’s start at the top. At the vertex is the superior frontal gyrus. This is easy to remember, bc it’s at the top—and being at the top is superior. It’s like the superior king at the top of the vertex.

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! 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!

1/Want to TRI to learn something new about the TRIGEMINAL nerve?

If you’re only looking at the skullbase, you are missing a significant part of the trigeminal nucleus!

Let my help you TRI to up your game when it comes to TRIGEMINAL anatomy 2/We normally think of the trigeminal nerve nucleus in the brainstem.

But the trigeminal nucleus actually extends into the spine like a ponytail called the spinal trigeminal nucleus.

1/Having trouble remembering what you should look for in vascular dementia on imaging?

Almost everyone worked up for dementia has infarcts. Which ones are important?

Here’s a thread on the key findings in vascular dementia 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

1/Ready to seize the day w/epilepsy imaging?

Everyone knows mesial temporal sclerosis (MTS)!

But did you know there are different KINDS of MTS??

Read on for this month's @theAJNR SCANtastic on what YOU need to know in the latest in epilepsy imaging!

ajnr.org/content/45/9/1…
2/The name of the “hippocampus” comes from its shape on gross anatomy.

Early anatomists thought it looked like an upside down seahorse—w/its curved tail resembling the tail of a seahorse.

Hippocampus literally means seahorse.

1/Have MULTIPLE questions about the new criteria for MULTIPLE sclerosis?

ECTRIMS 2024 just came out w/proposed new changes to the McDonald criteria for multiple sclerosis.

The changes are complex, but here is a thread w/the basics that you NEED to know! 2/The 2017 criteria were complex as well, but the basic theme was that they required dissemination in both time & space.

So you needed lesions in multiple locations and of multiple different ages.

1/“Tell me where it hurts.”

How back pain radiates can tell you where the lesion is—if you know where to look!

Do YOU know where to look?

Here’s how to remember the lumbar radicular pain distributions! 2/Why is it important to know the radicular pain distributions?

Most times patients have many POSSIBLE sources of pain--and when you are looking at an MRI, it's your job to decide which finding is the most LIKELY source of pain

These pain distributions can help you do that!

Having trouble visualizing the location of the visual cortex?

Wish you knew where to look for where you see?

Let me open your eyes w/a quick & easy way to find the visual cortex on imaging so that you’re never caught looking! 2/Coronal plane is actually the easiest plane to find the visual cortex because it is directly perpendicular to the Calcarine fissure.

1/Hate it when one radiologist called the stenosis mild, the next one said moderate--but it was unchanged?!

How do you grade it?

Do you estimate? Measure? Guess???

Here’s a thread about a lumbar grading system that’s easy, reproducible & evidence-based! 2/Lumbar stenosis has always been controversial.

In 2012, they tried to survey spine experts to get a consensus as to what are the most important criteria for canal & foraminal stenosis.  

And the consensus was…that there was no consensus

So what should you use to call it?

1/Nothing is more CENTRAL to reading an MRI than finding the CENTRAL sulcus?

How do YOU find it?

Are you just using gestalt when you say “frontal” or “parietal”? 

Time to recenter your search pattern with this thread on how to find the central sulcus on a brain MRI! 2/On axial images, at the very top of the brain, the superior frontal gyrus & precentral gyrus combine to look like a bent knee

You can remember that bc precentral is the motor strip & you move by bending your knee!

1/Sometimes the tiniest thing can be the biggest pain—that’s microvascular compression of the trigeminal nerve!

But seeing such a tiny finding can be hard!

Here’s a thread about how to look at the trigeminal nerve on MRI! 2/The most important thing to remember is that the nerve is 3D so you have to look at it in all three planes.

So what is the normal and abnormal appearance of the trigeminal nerve in each plane?

1/Feeling mad every time they ask you if it’s safe to give gad?

Do you know which gadolinium contrast material is safe to give?

At an impasse about the contrast class?

Read on as this month’s @theAJNR SCANtastic answers the question: Is Gad Bad?

ajnr.org/content/45/8/1…
2/Whether or not to give gadolinium is a common question, as almost 1/2 of all MRI studies use gadolinium contrast.

Contrast-enhanced imaging can help elucidate many different pathologies, including tumors, demyelinating disease, & infection

1/Do questions about brainstem anatomy cause you to suddenly get a case of locked in syndrome?!

Do you try to localize the lesion or just wait for the MR?

Wait no more!

Here’s a thread about the brainstem Rule of Four to help you localize brainstem lesions! 2/The hallmark of a brainstem lesion/syndrome is:

(1) Ipsilateral cranial nerve deficit

(2) Contralateral body deficit (be it weakness, sensory loss, or ataxia)

1/Is your understanding of medial temporal anatomy, well, temporary?

If only there was a way to make hippocampal anatomy memorable!

Here is a thread of the basics of hippocampal anatomy that will hopefully stay in your hippocampus! 2/Its name “hippocampus” comes from its shape on gross anatomy.

Early anatomists thought it looked like an upside down seahorse—w/its curved tail resembling the tail of a seahorse.

Hippocampus literally means seahorse.

1/Tired of stressing if a brain tumor is progressing?

Wish you had some insurance about calling tumor recurrence?

Here’s the cheat sheet you NEED for the best signs of tumor progression! 2/Just when treatment thinks it’s got tumor trapped at cliff, tumor is able to get away

Think how you would get away if you were chased to a cliff’s edge.

These are same signs of tumor progression!

1/Tired of always speculating about MR spectroscopy?

If you've ever looked at an MR spectroscopy & thought: "I have no idea what I’m looking at!"--then this cheat sheet is for you!

Here's a thread on the 4 basic rules you need to understand the spectrum of basic spectroscopy! 2/First you need to know the peaks.

There are 3 main peaks: Choline, Creatine, NAA

Remember the order bc a spectrum looks like mountain peaks & it is cold in the mountains.

And CHOld CREATures NAp or hibernate in the mountains

1/Wish that your knowledge of autoimmune encephalitis was automatic?

Do you feel in limbo when it comes to the causes of limbic encephalitis?

Do you know the patterns of autoimmune encephalitis?

Here’s a thread with some hints to help you figure it all out! 2/Two pearls:
(1) Most common pattern is limbic encephalitis
(2) Small cell can cause any autoimmune pattern.

You can also remember the causes by the demographic:
🔸Young man: testicular
🔸Older: Small cell
🔸Woman with psychiatric symptoms: breast

1/To call it or not to call it? That is the question!

Do you feel a bit wacky & wobbly when it comes to calling normal pressure hydrocephalus on imaging?

You don’t want to overcall it, but you don’t want to miss it either!

Let me help you out w/a thread about imaging in NPH! 2/First, you must understand the pathophysiology of “idiopathic” or iNPH.

It was first described in 1965—but, of the original six in the 1965 cohort, 4 were found to have underlying causes for hydrocephalus.

This begs the question—when do you stop looking & call it idiopathic?