0:01

Let's talk about that practical

0:03

approach that I mentioned before.

0:04

So if you have someone pulmonary fibrosis, so you know,

0:07

what is pulmonary fibrosis, reticulation,

0:09

these tiny little lines in lungs, traction,

0:12

bronchis honeycombing.

0:13

I think everyone knows that they're dealing with a case

0:15

of pulmonary fibrosis on HR ct,

0:18

even if they don't have any formal training.

0:21

Why is that? I don't know. It's just, it seems obvious even

0:23

to medical students when I show them an HRCT

0:26

that has pulmonary fibrosis on them,

0:28

even if they don't have never seen pulmonary

0:31

fibrosis before.

0:32

And I haven't really taught them about pulmonary fibrosis.

0:34

If I show 'em an HRCT, oftentimes they'll see things like,

0:38

oh, that looks like scarring, or something like that.

0:40

Which is essentially what fibrosis is.

0:41

It's a, it's a progressive type of scarring of the lungs.

0:45

And so I don't know what it is,

0:46

but there's something about it

0:47

that I think is quite characteristic.

0:49

But once you know it's pulmonary fibrosis,

0:51

that's actually the hard part.

0:52

Now what do you do with it?

0:54

So I think this algorithm will help you quite a bit.

0:59

And so the first step is to look at that HRCT

1:01

and try to determine is this a typical UIP

1:04

or a probable UIP pattern on ct?

1:07

If it is, as a radiologist, you're done.

1:09

You could drop that mic, you're done.

1:11

You've achieved the answer from a radiological standpoint.

1:16

Why is that? I'll tell you in just a little

1:17

bit why that's the case.

1:19

But typical UIP, probably UIP,

1:21

when we see this pattern, we should be quite happy.

1:23

'cause this is actually when we are most accurate in terms

1:26

of predicting what the UIP pattern would be had we be able

1:29

to do X explan and look at the whole lung.

1:33

If it's not typical UIP

1:34

or probably UIP, you gotta go to the next step.

1:36

You gotta ask yourself, is this a high confidence pattern?

1:39

Like I will eat my hat if it's not this diagnosis kind

1:42

of pattern of nonspecific interstitial pneumonitis,

1:46

hyper pneumonitis or sarcoidosis.

1:48

You're gonna hear me interchange pneumonia and pneumonitis.

1:52

A lot of people do this and so they are interchangeable.

1:55

But I will say, I think the favored P

1:57

nomenclature is to call it pneumonia.

1:58

So nonspecific interstitial pneumonia, same thing

2:01

as nonspecific interstitial pneumonitis.

2:03

Okay? But you're gonna hear me kind

2:05

of use them interchangeably because I just

2:07

can't, I can't keep it straight.

2:08

Uh, just, it just comes out naturally.

2:11

If you can, you're, again,

2:13

we're done from an imaging standpoint.

2:14

You drop the mic and you say,

2:15

this is a high confidence pattern for one of these different

2:19

alternative disease categories, NSIP, HP or sarcoidosis.

2:25

And then step three is, well,

2:27

you gotta kind of have to punt.

2:28

So if it's not one

2:29

or two, then it's probably something weird.

2:32

And so within the framework

2:34

of pulmonary fibrosis diagnosis on imaging,

2:38

you have two categories that you can leverage

2:41

to address these cases.

2:43

So one is the alternative diagnostic category.

2:45

These are cases where you're essentially saying,

2:47

this just does not look like UIP does not feel like typical

2:51

UIP or probable UIP.

2:53

This feels like something else.

2:55

Um, and maybe you just can't put your finger

2:57

on exactly what it is.

2:58

And then there's the indeterminate for UIP category,

3:01

which is a great category.

3:02

The indeterminate for UIP category essentially is saying,

3:05

I have no idea what this is.

3:07

I don't think it's UIP,

3:08

but I'm not confident that it's something else.

3:10

I don't know what pattern this is.

3:11

This is kind of thrown up your hands.

3:12

And so this pattern is often invoked in cases

3:17

of very mild pulmonary fibrosis where you're like, Hmm,

3:20

I don't really, is this early NSIP?

3:22

It's early UIP. It could be early hp.

3:24

I mean, there's a little bit of air trapping.

3:25

You're just not quite sure.

3:26

So that's good for interterm of UIP

3:28

or for more advanced cases

3:30

where you just really have no clue.

3:32

And so I call it punting.

3:34

Again, you're not really sure what

3:35

to do, but this is helpful.

3:36

If a radiologist says, I have no clue what it is,

3:39

then this actually acts more like this alternative

3:42

diagnostic category,

3:43

like a non UIP category than it does UIP.

3:47

I wanted to just underline this fact.

3:49

I know I mentioned this before. Remember,

3:50

multidisciplinary diagnosis is the gold standard in

3:53

achieving diagnosis in interstitial lung disease

3:56

and pulmonary fibrosis.

3:58

It's just the way it is. And why is this?

4:00

Is 'cause we're not talking about one single little nodule

4:02

that you're sticking a needle and you're doing biopsy on.

4:04

Right? In those cases, you can be pretty sure

4:07

whatever the pathologist tells you is gonna be accurate.

4:09

Like, like there's no way that if you,

4:11

you cord out a big hunk of a pulmonary nodule, he came back

4:14

with lung cancer, there's no way the radiologist's gonna

4:16

come back to the pathologist and the pulmonologist

4:18

or oncologist and say, oh no, this is not lung cancer.

4:21

This is something else. No way, right?

4:23

Pathology, that's gonna be the gold

4:24

standard diagnosis in that setting.

4:26

But an ILD, because you have a diffuse lung disease,

4:29

you can either sample if you're doing surgical lung biopsy

4:32

areas that are too fibrotic,

4:34

or maybe just the fact that it's,

4:36

it's such a diffuse process, you're gonna sample areas

4:38

that maybe don't give you the right answer.

4:40

And so there is some data out there,

4:42

a little older data now,

4:43

but it shows that if you get a pathologist

4:45

and you give them their pathological slides

4:48

and then you bring the pathologist back to an MDD setting,

4:52

multidisciplinary diagnostic setting,

4:55

and then everyone discusses the cases,

4:56

the pathologist will change his

4:58

or her mind in about 20% of cases, 20% of cases.

5:03

That's crazy, right? So no way would that happen

5:06

with a pulmonary nodule.

5:07

Again, we're gonna trust what the pathologist says

5:09

by the setting of interstitial lung disease

5:11

and pulmonary fibrosis.

5:13

MDD is really what we're gonna be trusting.