0:00

So now let's talk about NSIP.

0:02

And so now what, where are we in the practical approach?

0:05

We've gone past step one.

0:06

So let's say it's not a high confidence typical UIP pattern

0:11

or a probable UIP pattern.

0:13

It looks like something else. So now we've gone to step two.

0:15

So we're asking ourselves, is it NSIP, is it hp?

0:19

Is it sarcoid? But

0:21

with a high confidence sort of level, right?

0:24

So now is it not as like are

0:25

there some elements of these things?

0:27

Is it like, will I eat my hat?

0:29

You know, I'll eat my hat if it's not this sort

0:31

of specific disease pattern.

0:33

Okay. And so the first thing we're gonna start with is NSIP,

0:36

non-specific interstitial pneumonitis.

0:38

The first thing to remember about NSIP is

0:41

that these cases are usually secondary.

0:43

I alluded to before that UIP, most

0:46

of those cases are usually idiopathic pulmonary fibrosis.

0:49

Again, not all of them, but most of them.

0:51

So if we actually do the numbers, UIP with IPF,

0:53

it's about 70% of UIP cases are IPF

0:58

with NSIP, it's the converse.

1:00

So almost all cases

1:02

of NSIP will be secondary to something else.

1:06

And so things that we think about are connective tissue

1:08

disease, sometimes hypersensitivity, pneumonitis,

1:11

and drug related pulmonary fibrosis.

1:14

In this disease setting, you're looking

1:16

for basal predominant disease.

1:18

In fact, I'd say NSIP is even more basal predominant than

1:21

UIP, but it's less coarse in most cases.

1:25

So instead of seeing a lot of reticulate abnormality,

1:27

you can see reticulation as well.

1:29

But very often you're gonna see a significant amount

1:31

of ground lass opacity

1:33

and sometimes it's gonna be a pure ground opacity without

1:36

much superimposed reticulation.

1:39

In these patients with NSIP, it's not uncommon

1:42

to get this exuberant traction bronchiectasis,

1:44

though it's not part of the diagnostic criteria.

1:47

But I'll tell you the most high confidence thing

1:50

that tells you this NSIP is the distribution.

1:53

So in the axial plane,

1:55

if you have a central lung preponder pattern

1:57

or relative subpleural sparing, I'll show example

2:00

of it in the next few slides.

2:02

You can be fairly confident.

2:04

I shouldn't even say fairly, you can be very confident.

2:06

This is a case of NSIP, all case of UIP,

2:10

especially in the setting of idiopathic pulmonary fibrosis.

2:13

They start from the lung periphery, subpleural lung

2:16

and they march inward.

2:18

So if you see any evidence of subpleural sparing,

2:20

it really draws you away from UIP toward

2:22

alternative diagnoses.

2:24

And then really the pattern

2:25

that you wanna think about in those settings is NSIP.

2:28

So subpleural sparing,

2:29

you should be thinking about NSIP one, two and three.

2:32

Don't start thinking about UIP until

2:34

you've exhausted all other alternative etiologies.

2:40

Here's an example of NSIP, clearly basal predominant.

2:42

You see how there's bore ground glass here?

2:44

It's a prettier pattern, maybe a little bit

2:47

of traction bronchiectasis in some areas.

2:49

This is NSIP being pretty typical.

2:52

Another example of NSIP

2:53

and some with interstitial pneumonia

2:55

with autoimmune features, right?

2:57

So this is a subtype, um,

2:58

An experimental subtype.

3:00

We haven't really defined it yet of someone

3:02

who has connected tissue disease like disease.

3:05

So not a defined connect tissue disease,

3:07

but patients who in the clinicians are thinking might have a

3:10

subtype of connect tissue disease.

3:12

And so sequential axial images clearly base are predominant.

3:15

See how there's more wrong loss here than were reticulation.

3:18

There's just some mild reticulation

3:20

and you can kind of hallucinate

3:21

some relative subpleural sparing.

3:23

You really gotta hallucinate. Sometimes you really gotta

3:25

look and and maybe do a prone

3:27

and try to try to show it to your friends

3:29

and try to figure out whether there is

3:31

relative subpleural sparing or not.

3:32

Here's the prone to reformation.

3:35

And so again, I think that maybe there's a little bit

3:38

of relative subpleural sparing,

3:39

but I think this is a soft call.

3:40

This would be one where I wouldn't be confident

3:42

of any sort of subpleural sparing.

3:43

But again, it just has that flavor.

3:46

Here's another example of NSIP

3:48

and this patient actually had hypersensitivity pneumonitis.

3:51

We see this central ground lap opacity.

3:54

A little bit of consolidation here.

3:55

So you start thinking about maybe some superimposed

3:57

organizing pneumonia.

3:59

When I see this pattern, I actually start thinking about

4:01

myositis, which is a type of connected disease.

4:03

But this patient end up having hypersensitivity pneumonitis.

4:06

But look at this beautiful subpleural sparing on the coronal

4:09

reation, which again is great for distribution.

4:11

This is two dye for subpleural sparing.

4:14

Look at this along the hemi diaphragms bilaterally.

4:16

Completely spared there.

4:18

So this is like a textbook case of subpleural sparing.

4:21

NSIP as I alluded to

4:23

before, you see the ground lasts in NSIP,

4:25

but very commonly you'll see this

4:27

traction bronchiectasis sometimes out of proportion

4:30

to the degree of underlying macroscopic pulmonary fibrosis.

4:34

Beautiful case NSIP here, another patient with NSIP,

4:39

a little bit more reticulation here as well.

4:41

There is some mild ground left opacity superimposed on it.

4:44

Clearly some traction bronchis.

4:45

But look, look at the subpleural spar least

4:48

relative sub flowal sparing.

4:49

The coronal reformation I think is really good for looking

4:52

for subpleural sparing.

4:54

And I think that's something that's not leveraged as much.

4:55

So I encourage you, if you guys aren't using coronals

4:58

to look at these HR cts in terms of distributions,

5:01

I encourage you to do so.

5:04

So we're gonna take a little bit of a tangent here.

5:06

This still is about NSIP, right?

5:08

But this is, uh, about a sign.

5:10

So there is a sign called the STRAIGHTED Sign.

5:14

And so this sign has been shown

5:17

to help us differentiate UIP from NSIP on

5:21

the Coronal Reformation.

5:22

And really the best way to see this is on that coronal.

5:25

And so that's again why I encourage you to use

5:27

that coronal reformation for delineation of distribution.

5:31

And so UIP on the coronal, it tends

5:34

to creep up the sides like this.

5:36

I I like to call it meniscus sign. That's not a real sign.

5:38

Don't say meniscus sign if you're a resident or a fellow.

5:40

Don't say, oh yeah, meniscus.

5:42

Jonathan Chung was talking about meniscus sign.

5:43

Uh, 'cause your attending will probably get mad at you.

5:46

Um, yeah, don't, don't throw me under the bus like that.

5:48

But bottom line, I like to think of this like a meniscus,

5:51

kinda like fluid crawling up the sides of like a little,

5:53

little test tube as opposed to NSIP

5:56

Very commonly on the Corona Reformation,

5:58

it has a straight edge morphology like this.

6:01

And so like with the edge of your paper,

6:03

you can delineate normal from abnormal lung.

6:05

You see the straight edge sign much, much more likely

6:08

to be NSIP than UIP.

6:10

Here it is sort of translucent as you can see here.

6:12

So meniscus, UIP, straight edge NSIP.

6:16

We have some data we published on this a while ago.

6:18

And so this is dual center, so national Jewish

6:20

and Denver, where I previously worked near Chicago

6:22

where I previously worked.

6:24

And so we had data from both places

6:25

and both places showed that again,

6:27

if you have straight edge sign, the NSIP pattern,

6:30

NSIP is gonna be much more likely than UIP.

6:32

This was based on a pathological gold standard

6:36

bonus imaging pearl.

6:37

And so this also includes a straight edge sign.

6:40

So this is a slightly different disease setting.

6:42

So this is not something where we're trying to differentiate

6:45

NSIP from UIP.

6:47

This is more in the setting of UIP.

6:49

So what did I say before about UIP?

6:52

I said most cases about 70% of cases of URP are gonna be due

6:56

to idiopathic pulmonary fibrosis.

6:58

But if 70% are due to IPF,

7:00

that means 30% are due to something else.

7:03

And so a big chunk of those 30%, which are not due to IPF,

7:07

but have a UIP pattern are actually due

7:09

to connective tissue disease.

7:11

So things like rheumatoid arthritis,

7:12

sometimes mixed connective tissue disease,

7:14

sometimes even systemic sclerosis,

7:16

which usually gives you NSIP that's gonna can manifest

7:20

as a UIP pattern.

7:22

And so the any one of these three signs, if you have them,

7:26

and if in someone with UIP on imaging,

7:29

it should start pushing you toward a diagnosis

7:32

of a connective tissue disease related ILD rather than a UIP

7:37

from idiopathic pulmonary fibrosis.

7:40

These signs are the anterior upper lobe sign,

7:42

the straight head sign, which I just showed you,

7:43

and the exuberant honeycombing sign.

7:46

So the anterior upper lobe sign, what is this?

7:48

It's when you have pulmonary fibrosis,

7:50

not just at the lung bases,

7:51

but also in the anterior aspect

7:53

of the upper lobes bilaterally.

7:54

Other people have called this the propeller sign.

7:56

Other people have called this the four corner signs.

7:58

So Dr. Christian Cox, who I used to work

8:01

with in Denver now works in Nebraska as a chair there.

8:05

He coined the term, uh, the four corner sign.

8:07

I like that as well. So, you know, four corners.

8:09

One in the antra upper lobe is one of the,

8:11

the posterior lower lobes

8:12

and it's bilateral, so it's four corners.

8:14

If you have this and you have UIP, much more likely

8:16

to be connect than idiopathic pulmonary fibrosis.

8:20

And again, as I alluded to, if you have the straight edge

8:22

sign and you had a UIP pattern, then you're,

8:24

it's gonna be much more likely

8:25

to be connect disease than idiopathic pulmonary fibrosis.

8:28

We already defined what that is.

8:30

And then exuberant honeycomb sign also, again, very,

8:32

very suggestive of connected tissue disease rather than

8:36

idiopathic pulmonary fibrosis.

8:38

What is exuberant honeycombing sign?

8:40

It's if over 70% of the fibrosis, so none of the lung,

8:45

70% of the fibrosis is comprised of honeycomb cyst.

8:49

So bottom line, you have a case of clear pulmonary fibrosis,

8:52

but all the fibrosis

8:54

or nearly all the fibrosis is comprised

8:56

of these honeycomb cyst.

8:57

Very commonly the honeycomb cysts are larger

8:59

than you typically see.

9:01

If you see this, you should be thinking about connects

9:04

rather than idiopathic pulmonary fibrosis.