2/Many know anterior circulation ASPECTS. It uses a 10 point scoring system to semi-quantitate the amount of the MCA territory infarcted on non-contrast head CT.
If you need a review: here’s my tweetorial on ASPECTS:
3/But it’s only useful for the anterior circulation. Posterior circulation accounts for ~25% of infarcts. Even w/recanalization, many of these pts do poorly bc of the extent of already infarcted tissue. So there’s a need to quantitate the amount of infarcted tissue in these pts
4/Posterior circulation ASPECTS, or pc-ASPECTS for short, is also a 10 point system—but for the vertebrobasilar circulation. Patients get points for each region NOT infarcted on the initial CT.
5/Similar to anterior ASPECTS, points are GOOD
It’s like a city—when a region infarcts, it is like the lights go out in that city region (literally, tissue darkens on CT)
In ant & post ASPECTS, you are counting the regions where the lights are still on—so high ASPECTS is good
6/Which regions get scored?
The biggest prognostic factors in posterior strokes are time & amount of already infarcted tissue.
It’s a little different than anterior ASPECTS, where every region just got one point
For pc-ASPECTS, think of it like a mother. She only has 2 arms. So if there are two kids, they have to split the arms—only one arm can be wrapped around each kid
8/So unpaired structures, like the brainstem, are like having only one kid—you get both arms wrapped around you = 2 arms = 2 points.
If the structures are paired, like the cerebellum, it’s like having two kids--they must split the arms. Each gets only 1 arm = 1 point
9/So lets go through our regions using the mnemonic.
Each thalmus is worth only 1 point, bc they’re paired & have to share their mother’s arms.
The unpaired midbrain is worth 2 points (gets both arms)
10/Pons is unpaired, so it is worth 2 points.
But the paired cerebellar hemispheres & occipital cortex are each only worth 1 point per side, as each side claims only one of the mother’s arms
11/While there’s evidence that higher pc-ASPECTS means poorer outcome, there’s no consensus about what pc-ASPECTS score definitively confers a UFO (unfavorable outcome).
But the consensus about what confers a UFO in anterior circulation ASPECTS may change soon as well!
12/So now you know the regions & scoring for pc-ASPECTS!
Remember, the anterior circulation isn’t the only aspect of ASPECTS!
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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.
3/Proposed new criteria bring a paradigm shift from relying on a combination of dissemination in both space in time, to relying on other factors that can replace dissemination in time
It also proposes that new imaging features specific to MS can be used in diagnosis as well
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!
3/Let’s start with L1. L1 radiates to the groin.
I remember that b/c the number 1 is, well, um…phallic.
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?
3/Well, you don’t want just gestalt it—that is a recipe for inconsistency & disagreement
But you don’t want to measure everything either—measurements are not only cumbersome, they introduce reader variability & absolute measurements don’t mean the same thing in every patient.