0:01

Questions.

0:02

Okay. You were gonna take that.

0:03

I think we have one question from earlier.

0:07

I think this is a good one for you.

0:09

Um, uh, Heather, do you use 3D isotropic sequences

0:13

for nerve imaging and in, so, uh, which sequences do you use

0:18

Sometimes?

0:20

So if we are getting cases specifically from a surgeon

0:24

who has a pretty high suspicion of, uh,

0:27

like an anterior neuro

0:29

or posterior neuro osseo sphe syndrome,

0:31

and we're really trying to get that detailed evaluation, uh,

0:34

we will do an isotropic, uh, usually a T one

0:37

and a fluid sensitive.

0:38

So we'll do like a T two sequence as well, um,

0:41

and really use those thin, thin, um, projections.

0:44

It has to be that you have a pretty high suspicion of

0:47

where the abnormality is, um, because

0:49

otherwise they're gonna take forever.

0:51

Right. And you'll be doing kind

0:52

of axial thin axial acquisitions for an hour.

0:56

Um, and so we really use it in a pretty limited fashion.

0:59

If we're, if we're looking more for unknown cases, you know,

1:03

some sort of, of radial nerve entrapment,

1:05

then we'll often just do kind

1:06

of a more routine approach to those cases.

1:09

Megan, does it depend on the, um, the scanner that you're,

1:13

you're scanning with and the age of the scanner,

1:14

whether you use 3D?

1:16

Yeah, sure. You bet.

1:17

And it just depends on how much scan time it is

1:20

and what, what's available.

1:21

If we're imaging three T

1:22

or if we, we only have one five available,

1:24

then sometimes we'll kind of, uh,

1:26

we'll tailor those sequences to the,

1:28

the different opportunities that we have.

1:29

What we can, we try to image on, you know,

1:32

three T higher Tesla strength is certainly gonna help if

1:35

they're post-surgical cases, we will avoid that.

1:37

Right. To kind of reduce the amount of artifact.

1:41

Okay. Megan, another question I think that's,

1:43

uh, apropos for you.

1:44

Um, can you structurally identify the arcade of fros

1:48

and the leash of Henry on imaging?

1:50

Yeah, so I think actually the case that you showed

1:53

of posterior osseous nerve

1:54

and we were able to identify some

1:56

of those different anatomic regions of

1:58

that posterior interosseous nerve.

2:00

Uh, you can look for those different structures,

2:02

whether you're very superficial in that supinator muscle

2:05

or whether you're kind of deeper within

2:06

the muscle belly itself.

2:08

Uh, those are kind of, um, ways

2:10

that you can help distinguish some of these different areas.

2:13

And again, as you, as you noted, the named kind of sites

2:16

of entrapment really are about anatomic as much as they are

2:19

what is causing the entrapment.

2:21

So if you have prominent vasculature, right, you're,

2:24

you're more concerned about a, a a a of an entrapment

2:27

of the, of, from the vasculature itself as opposed to like

2:30

that supinator arch,

2:31

which is gonna be super more superficial in that region.

2:35

And I just threw up a quick picture.

2:36

I don't know if it's displaying,

2:37

I just threw up a quick picture

2:39

of the supinator arch right here.

2:41

Um, another question I think, uh, for you, uh, do you see

2:46

cystic de degener degeneration

2:48

of the nerve fales Megan in compressive neuropathy upstream

2:53

and downstream of the compression site?

2:56

And I think this is a really interesting one,

2:58

is cystic degeneration reversible?

3:02

Um, so usually it's downstream, you can get a little bit

3:05

of proximal migration.

3:08

Usually we see that more in like traumatic injury,

3:10

so if you have a complete transection of the nerve

3:12

as opposed to a compression phenomenon,

3:14

so typically more downstream.

3:16

Uh, and so if you do see some major, uh, cystic, uh, kind

3:20

of changes in the nerve, if you wanna kind

3:21

of search proximally to see if you can identify that side

3:24

of compression, uh, but it can be close

3:26

and sometimes it's hard to tell exactly where it stops.

3:28

It stops and finishes there.

3:30

Um, cystic degeneration reversible?

3:32

Uh, that's a good question.

3:34

I think you can get some reversal

3:36

of the cystic change within the nerve.

3:38

So they, they certainly, we see those po postoperative cases

3:41

where it's not as enlarged.

3:42

Um, I don't know that it ever really returns to normal, um,

3:46

but you can get some definitely decreased, uh, kind

3:50

of pronounced findings in those cases

3:51

after they undergo, um, decompression.

3:54

As far as the timeline, I don't know, I,

3:56

I suspect it'll have to do with how long

3:59

and how severe that compression is

4:01

and how extensive that, uh, that neuro esis

4:04

or the axi esis as you mentioned, um,

4:06

whether it's a complete degeneration

4:08

of the axons or whether it's partial.

4:10

Uh, and so I think that the time course may depend on that.

4:12

I'm not sure about that. Do you, do you happen to know?

4:15

I don't know, but I, you know, I've dealt a lot

4:17

with athletes in lower extremities

4:19

and seen a lot of perineal nerve cystic degeneration,

4:23

and I, I have ne I've never seen any one of those

4:27

revert back to normal, although the patients have gotten

4:29

somewhat better, but they've ne

4:30

they've never gone back to normal.

4:32

But I don't know the answer to it. Okay.

4:35

Are there, is, is that all of our, all of our questions

4:40

Question about T one? Yeah.

4:41

So a question was asked earlier,

4:44

it's not entrapment neuropathy related.

4:46

Um, the, the audience noticed that we included, um,

4:51

non-fat sat T one images in one

4:53

or all planes of our protocols

4:55

and many centers now omit

4:57

a non-fat sat T one weighted image to save time.

5:01

Um, neither, neither Don nor I omit that.

5:05

Uh, we think it's a really important sequence.

5:07

It helps me quite a bit when I'm characterizing bone

5:10

lesions, not only bone lesions or masses,

5:13

but also fractures.

5:14

And Dr. Chung responded

5:16

before she logged off, she said, I like

5:19

to have a non-fat sat T one imaging and one imaging plane.

5:23

The shorter t offers slightly better resolution,

5:26

a minor advantage, but I like

5:27

to assess joint fluid versus synovial

5:30

hypertrophy on this sequence.

5:32

Low T one signal with muscle

5:34

as an internal standard equals simple fluid.