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One of the scariest moments in an emergency

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department radiology resident's life is when

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you get sent down a study for a neonate where

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the concern is hypoxic-ischemic encephalopathy.

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What I recommend you do is get out your textbook,

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uh, either by Kovitch or otherwise, and sort of review

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it because these are very difficult studies to read.

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Remember that the neonatal brain is basically

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non-myelinated tissue, where everything looks

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kind of watery, and if the patient is a

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premature, uh, child, uh, neonate, then that

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development of the brain is even more immature,

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and it really looks like a bag of water.

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And here you have a patient who you're

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worried about ischemic injury or traumatic

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injury from the, uh, delivery, and you're

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having to read it. It is quite difficult.

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So even me, 30 years later and 30 years

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into reading neuroradiology cases and

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pediatric cases almost every day,

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it gets a little bit concerning.

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This was one of the cases that I actually called

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one of our pediatric neuroradiology specialists,

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one of my colleagues, Ilan Teon,

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and said, "Am I reading this right?"

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So this child, you know, had a traumatic birth, and

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the question was hypoxic-ischemic encephalopathy.

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Here is the T2-weighted scan.

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As you can see, there's like absence—complete

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absence—of gray-white matter differentiation,

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which is typical of a neonate, particularly a premature

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neonate. And I look at this T2-weighted scan.

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All I can really comment on is that the

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ventricles don't look big and that the

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scan is symmetric from right to left.

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Now, one of the areas that you want to

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concentrate on is the caudothalamic notch.

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That's where hemorrhages can occur in premature

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infants that may have hypoxic-ischemic injury.

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And because this is a very vulnerable

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area, in this case, I passed that.

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I think these were just veins—internal

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cerebral veins—coming to the vein of Galen.

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So nothing focal, no midline shift.

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And the T2-weighted scan is not revealing.

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If you go to the FLAIR scan, the

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FLAIR scans are virtually useless

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also in patients who are being evaluated with

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hypoxic-ischemic encephalopathy. Here's a FLAIR scan.

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Nothing much showing here.

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Maybe a little bit of bright

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signal in the subarachnoid space.

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So for hypoxic-ischemic encephalopathy, obviously,

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the images that you want to focus on are the

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diffusion-weighted scan and,

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surprisingly, also the T1-weighted scan.

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The T1-weighted scan may show some

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elements of bright signal intensity

3:01

that may occur in the basal ganglia.

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When you have an ischemic injury,

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in this case, you normally have some

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bright signal in the globus pallidus region.

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You don't want to see it in your thalami, and you obviously want to also look

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for bright signal intensity that might suggest

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subacute hemorrhage with methemoglobin.

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So looking at the T1-weighted scan, and frankly, I've

3:21

read this again as not showing anything in particular.

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However, when we look at the diffusion-weighted

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scan, what you see is that it seems as if there

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is accentuation of the gray matter compared to

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the white matter on the diffusion-weighted scan.

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Now, you might not recognize that.

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Even in itself when I'm showing it to you right

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to left here, where it's so symmetrical, but

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look at the dramatic difference between the

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temporal lobes and the cerebellum and brainstem.

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This is the normal signal intensity that one would

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expect to see on a DWI darkened signal intensity.

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This is diffuse abnormality in

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the gray matter of the cortex.

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In a patient bilaterally and symmetrically.

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So symmetry usually is your friend.

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In this case, this is diffusely abnormal in the

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entire supratentorial space, with some sparing of the

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cerebellum, maybe some involvement of the anterior pons.

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Here on the ADC map, again, this darker signal

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intensity in the cortex is diffusely abnormal.

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Let's compare that to the normal appearance

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of the cerebellum.

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So this striking difference between the sulcal

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space versus the cerebellum is the key that

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this is a diffuse, bilateral, symmetric process.

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So I read this as severe hypoxic-

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ischemic involvement of the entire cerebrum.

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I was a little nervous about it.

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I called up Ireland and said, can you

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verify with me for this?

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She said, yes, I agree.

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And unfortunately, this child

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did very poorly in the NICU and expired shortly

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thereafter from the diffuse HIE injury from

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the acute ischemic neonatal injury to this child.