0:00

So diffusion pitfalls, uh, just like in adults, right?

0:03

If you're not doing in the first like few days,

0:06

which often happens because you're cooling them and stuff,

0:09

or they're not stable, then it

0:11

could pseudo normalize, right?

0:12

So pseudo normalization, um, happens like around a week.

0:16

Uh, so timing is one thing. Also the gradient.

0:18

So what we call the B value, the gradient strength.

0:21

So babies are, are, uh, less an isotropic

0:25

'cause they're not myelinated, right?

0:26

So in adults we typically do B of a thousand as a standard.

0:30

Uh, but in kids we often do B value seven or 800

0:33

because they're more watery, right?

0:35

There's nothing to measure. Um, you can go higher.

0:38

You could go to like, let's say B of 2000

0:40

and you could exaggerate the contrast,

0:42

but you could also over call, right?

0:43

Because you might be exaggerating the

0:45

normal physiologic contrast.

0:46

And if you're not familiar with that appearance,

0:48

you might over call, um, ischemia.

0:50

Uh, and you can also do synthetic gradients.

0:52

So I, I recommend that honestly,

0:53

because if you already have like two, two B values,

0:56

zero in let's say 800, you can,

0:58

you can essentially generate other synthetic ones.

1:00

If you wanna just exaggerate contrast without trying

1:02

to overcall temperature's also an issue, right?

1:05

Because, uh, water molecules diffuse more slowly

1:08

at lower temperatures, right?

1:10

And more fast. So if you're cooling, you're gonna again, uh,

1:13

potentially overestimate the level of restriction.

1:16

And then as you rewarm

1:17

that pseudo normalization may actually be

1:19

stretched out in terms of time.

1:21

Um, so these were all kind

1:23

of like in the middle time period, like maybe like

1:26

around five to seven days where we did diffusion.

1:29

And as you can see, this one has only one spot,

1:30

but it was a moderate HII, it's just that, uh, a lot

1:33

of it had pseudo normalized by then.

1:35

This was a MCA large, uh, large vessel occlusion,

1:38

but only the lenticular trites are

1:40

like, you know, fully restricted.

1:41

The rest was partially pseudo normalized.

1:44

And then these areas again, so, uh,

1:46

if it's a severe insult, right?

1:48

Moderate, severe, you have ongoing injury a day, five

1:50

to seven, that's pretty, that's pretty bad, right?

1:51

Because normally the diffusion stuff comes down

1:54

and starts to pseudo normalize after four days.

1:56

So if you're still seeing diffusion restriction,

1:59

even if you're only seeing like a little spot,

2:00

but the fact that you're seeing it later on means

2:03

that you're probably dealing with a more serious insult, if

2:06

that makes sense.