0:02

Hello and welcome to Case Crunch rapid case

0:04

review for the core exam, hosted by Medality.

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In this rapid-fire format, faculty will

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show key images along with a multiple-choice

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question, and you'll respond with your

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best answer via the live polling feature.

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After a quick answer explanation,

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it's on to the next case.

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You can access a recording of today's case review

0:21

and previous case reviews by creating a free

0:23

account using the link provided in the chat.

0:26

Today, we are honored to welcome Dr. Kaitlin Marquis

0:28

for a thoracic imaging board prep case review.

0:31

Dr. Marquis completed her radiology residency

0:34

at Mallinckrodt Institute of Radiology, followed

0:37

by a cardiothoracic radiology fellowship.

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She's now an assistant professor at the University of

0:42

Kansas and co-director of advanced cardiac imaging.

0:45

Questions will be covered at the end if time allows,

0:47

so please remember to use the Q&A

0:49

feature to submit your questions. With that,

0:52

we are ready to begin today's board review.

0:54

Dr. Marquis, please take it from here.

0:57

Perfect.

0:57

All right.

0:58

Good evening, everybody.

0:59

Thanks for joining us on this Monday.

1:02

We're excited to have you.

1:03

So the format will go through

1:05

20 to 25-ish, um, kind of rapid-fire questions,

1:10

high-yield, specifically, um, regarding chest for core.

1:14

I have no relevant disclosures.

1:17

So this is just kind of, um, a detailed,

1:20

uh, basically a detailed, um, overview of

1:26

what we'll kind of cover, um, from the

1:30

pamphlet that the ABR actually provides.

1:32

And so I think it's important to recognize that it's

1:34

predominantly chest radiograph, some CT, and maybe a

1:37

handful of MRs. In terms of topics, we'll kind of cover

1:41

each of these, but generally speaking, I think lung

1:44

cancer, including diagnosis and staging, uh, covering

1:48

mediastinal lesions, pleural, and then diffuse lung

1:51

disease, which can be kind of broken up into different

1:53

categories, which we'll see all three of these.

1:57

Um, and then chest X-ray, kind of the classic

2:00

lobar collapse, misplaced catheters, anatomy,

2:03

um, location, and they like asking things that you

2:08

may be more familiar seeing on CT, for example,

2:11

fibrosis, but showing it on radiograph and

2:14

then asking you what it is based on the pattern,

2:16

location, or distribution of the process.

2:20

So that's kind of what we'll go through today.

2:23

Um, let's start with a quick poll

2:26

and just get an idea of who we have in the audience.

2:35

Perfect.

2:36

Okay, so let's go ahead and get into the first case.

2:41

So the first case is a 70-year-old man with a

2:43

left-sided lung cancer, and the question is,

2:46

what is the nodal stage for the lymph node,

2:49

lymph node identified by the arrow?

2:52

Would this be N1, N2, N3, or N4?

3:00

All right.

3:00

Not, not too bad.

3:02

So, the majority of people said N3,

3:03

which is the correct answer.

3:07

So, what's the cutoff between N2 and N3 disease?

3:11

So, supraclavicular is actually anterior to the

3:14

first rib, whereas high paratracheal is posterior.

3:18

So, I think being able to recognize things

3:20

that they would ask, particularly those that

3:22

change management, such as an N2 versus an N3,

3:26

would be high yield.

3:29

And then here's an example of a

3:31

high paratracheal lymph node.

3:32

You can see the center is kind

3:34

of posterior to the first rib.

3:38

So, in terms of high-yield lung cancer staging,

3:41

N1 will be ipsilateral mediastinal,

3:44

ipsilateral hilar. N2 is ipsilateral mediastinal.

3:48

N3 is ipsilateral supraclavicular or

3:52

contralateral mediastinal.

3:56

And then a few other things that I think would be pertinent:

4:00

A satellite nodule, meaning another nodule

4:03

in the same lobe as the lung cancer, would be T3,

4:07

whereas a nodule in a different lobe on

4:09

the same side would be T4.

4:12

And then a nodule on the opposite side would be M1.

4:15

So, I think those are the big key points

4:17

about lung cancer staging that I would focus on.

4:20

They could also ask it in a different way and

4:22

say, what is the name of this lymph node station?

4:26

So, prevascular, peri-aortic, and then right paratracheal.

4:31

And remember that the cutoff for left versus right

4:34

is the left aspect of the trachea.

4:38

Okay, moving on. Case two: What is the Lung-RADS

4:41

for this right lower lobe nodule?

4:48

So, the majority of people said Lung-RADS 2.

4:52

And the reason is that it's most likely a

4:55

juxtapleural nodule or a subpulmonary lymph node.

4:59

So, less than 10 millimeters, and

5:02

abuts the pleura or the fissures.

5:04

I don't think there's a lot that they would ask in

5:06

terms of Lung-RADS screening, but I think recognizing

5:09

that a subpulmonary or subpleural lymph node,

5:12

uh, is just a benign Lung-RADS 2

5:14

would be something reasonable.

5:16

Um, a few other, kind of, high-yield

5:19

facts about lung cancer screening.

5:21

Um, to be eligible, you have a 20-pack-year

5:23

smoking history and you have, have to have smoked

5:26

within the last 15 years.

5:29

Age 50 to 80, and this is done annually.

5:34

And we use a low-dose protocol.

5:35

So, the recommended dose is less than 3

5:39

milligrays, and we use thin slices less than 2.5 mm.

5:43

We use 1 mm at our institution.

5:46

And importantly, we use an average diameter, um, rounded

5:50

to one decimal point, which is probably a little

5:52

bit different than what you do on regular chest CTs.

5:55

Um, and the category is based

5:56

on the most suspicious nodule.

6:00

All right, moving beyond kind of

6:04

the boring screening and cancer.

6:06

So, case number three: What is the best diagnosis?

6:15

All right, perfect.

6:15

More than half, again, got the answer

6:17

correct, which is bronchial atresia.

6:23

So, bronchial atresia is a developmental

6:25

anomaly that results from obliteration

6:28

of the proximal segmental bronchus.

6:30

And then, what we're seeing is kind of the distal

6:33

obstructed bronchus that gets filled with mucocele.

6:36

It results in that tubular opacity that's

6:39

surrounded by air, and it's most commonly found

6:42

in the posterior segment of the left upper lobe.

6:45

And in most patients, they're asymptomatic.

6:48

We just observe and do nothing.

6:50

Um, 20% of patients can get recurrent infections.

6:53

And in that setting, the answer would be to resect.

6:56

So, sometimes they'll show you the bronchial

6:59

atresia but then ask what to do next.

7:01

If the patient is asymptomatic,

7:02

it's do nothing—just observe.

7:04

If they're coming in with infection,

7:07

then the answer would be to resect.

7:10

All right.

7:10

Case number four is a patient presenting with fever.

7:14

What is the best diagnosis?

7:21

Perfect.

7:22

All right.

7:22

More than half of people said infected

7:25

sequestration, which is the correct answer.

7:28

You can see this systemic feeding

7:30

artery going to this consolidation,

7:32

which tells you that it's a sequestration.

7:35

They would have to show you the systemic feeding artery.

7:37

If they wanted to show you lipoid pneumonia,

7:40

for example, they would show you fat attenuation,

7:43

but it would probably be mediastinal windows.

7:46

Uh, and then pneumonia and aspiration would be

7:50

really difficult to differentiate just on CT.

7:54

And then this is kind of a two-part question.

7:56

So what is the best treatment?

8:03

Perfect.

8:03

All right.

8:04

I think our last question may have helped people

8:06

in picking the correct response, which is resect.

8:13

So for sequestration, resection is

8:16

the answer for anybody presenting with

8:18

hemoptysis or recurrent infections,

8:21

which was what this patient came in with.

8:23

And this is an aberrant formation of the segmental

8:26

lung that has no connection to the bronchial tree.

8:29

And we have intralobar or extralobar.

8:32

Importantly, both of them have systemic arterial supply.

8:34

So, like I said, either case, they'll

8:37

have to show you the systemic feeding artery.

8:38

179 00:08:39,985 --> 00:08:42,064 Intralobar is obviously more common.

8:42

Um, the venous drainage is typically

8:44

through the pulmonary veins, and it

8:46

has a shared pleura with the lung.

8:48

Whereas extralobar, they typically present

8:51

younger with respiratory distress, cyanosis,

8:54

and they have a separate pleural covering.

8:57

And then the venous drainage is often

8:59

through the right atrium or systemic

9:01

veins, and it can be outside the lung.

9:03

So intralobar is far more

9:05

common on test and in real life.

9:07

And the most common location would be the

9:09

left lower lobe 60% of the time.

9:14

All right, case number five, what is the best diagnosis?

9:23

So most people said congenital lobar emphysema.

9:27

So we'll kind of walk through, um, the

9:30

why that's incorrect, but the correct

9:32

answer is bronchiolitis obliterans.

9:34

So this is kind of your classic chest

9:36

differential for a hyperlucent lung.

9:39

And really the key here is

9:41

which side is their volume loss or

9:44

is the lung, um, hyperexpanded.

9:46

So in congenital lobar emphysema, you'll have

9:49

mediastinal shift away from the hyperlucent lung.

9:53

Whereas in bronchiolitis obliterans or Swyer-James,

9:55

you'll get volume loss and mediastinal shift

9:59

toward the hyperlucent lung, which is what we have here.

10:02

Um, and so that's the main difference in

10:04

terms of, uh, differentiating these two.

10:06

Obviously, we didn't see a great

10:08

pleural line to suggest a pneumo.

10:10

And typically, congenital pulmonary airway

10:12

malformation will present sort of as a cystic mass

10:15

rather than sort of a diffuse hyperlucent lung.

10:20

All right.

10:22

Next case.

10:24

What is the most likely cause?

10:31

Perfect.

10:31

All right.

10:33

This is, most people said a mass,

10:36

which is the correct answer.

10:38

So this is a classic kind of

10:39

appearance of left upper lobe collapse.

10:42

So you can see this veil-like opacity, uh,

10:45

with volume loss and maybe a little bit of

10:48

hyperlucency that represents the Luftsichel sign.

10:52

Um, and so typically in an outpatient coming

10:55

in, you're worried about an obstructing

10:57

mass causing this left upper lobe collapse.

11:00

So not quite as obvious as most of the other

11:02

collapses where you have, you know, significant

11:04

volume loss, but being able to recognize this

11:06

kind of veil-like opacity with the volume loss.

11:09

And then, um, considering that

11:11

there's an obstructing mass.

11:14

All right.

11:15

Another— you can see we, we are very chest radiograph

11:19

heavy because I think these are kind of the bread

11:21

and butter that we don't always see every day running

11:24

through the inpatient stacks, but are just important

11:27

almost Aunt Minnies that you should just recognize.

11:30

All right.

11:31

So what is the best next step?

11:38

All right.

11:38

Perfect.

11:39

So about a third of people got it correct.

11:42

Um, so let's go through. The best next step

11:48

I think would be an MRI phase

11:50

contrast to quantify this shunt.

11:53

So what we're looking at here is PAPVR or Scimitar

11:58

syndrome, where we have this anomalous right

12:00

lower lobe pulmonary vein draining to the IVC.

12:04

Um, and so to quantify the amount

12:05

of shunt, we can get an MRI,

12:09

um, and calculate the Qp/Qs, where we compare the flow

12:12

in the pulmonary artery to the flow in the aorta.

12:16

Um, and if that ratio is greater than 1.5,

12:18

then they'll typically go ahead

12:20

and treat and repair that PAPVR.

12:24

Um, in terms of other associations that they

12:26

could ask, um, the right upper lobe PAPVR

12:29

is associated with a sinus venosus ASD.

12:33

So recognizing what that looks like

12:34

on CT, I think just on a still image.

12:37

And then the right lower lobe, the Scimitar,

12:39

which is what this one is—Turkish sword—

12:42

is associated with a sequestration.

12:45

And the left upper lobe one is often isolated.

12:49

All right.

12:52

Case eight.

12:54

What is the most likely cause of the imaging findings?

13:03

All right.

13:03

Good.

13:03

The majority of people got this one correct.

13:06

Asbestos.

13:07

79%.

13:10

All right.

13:11

So we can see kind of the classic

13:13

holly leaf sign of the pleural plaques.

13:16

Um, and this is what the CT correlate looks like.

13:19

You can see these calcified plaques that involve

13:21

the diaphragmatic and costal pleura. Um, and it

13:25

typically is the parietal pleura that's involved.

13:29

And you can get the incomplete border sign on a chest

13:32

radiograph, uh, because it's a pleural process.

13:36

Um, and then we typically reserve "asbestosis"

13:40

as the actual pathologic, uh, pulmonary

13:43

fibrosis that results from asbestos.

13:46

And there's a higher increase of lung

13:48

cancer even compared to mesothelioma.

13:53

All right.

13:54

Case number nine. What lobe is abnormal?

14:02

All right.

14:02

There was some discrepancy on this one.

14:05

Um, most people said right upper

14:08

lobe, which I could see why.

14:12

Um, but the correct answer is right lower lobe.

14:15

So I think you can kind of see—I think people

14:18

maybe thought this was kind of an S-sign

14:19

of Golden, but see how almost see-through

14:22

that is, we're just looking at kind

14:23

of mediastinal fat and vessels here.

14:26

But here, you can see in the right lower lobe this kind

14:28

of triangular opacity that points toward the hilum.

14:33

Um, and this is a right lower lobe

14:34

collapse due to an obstructing mass.

14:40

You can still see the right heart border,

14:42

so we know it's just the right lower lobe.

14:46

If they showed you, uh, the right heart border

14:48

being obscured, then you would think about some

14:50

sort of lesion in the bronchus intermedius,

14:52

causing right middle and lower lobe collapse.

14:56

All right, case number 10.

14:59

What is the most likely cause?

15:04

This is sort of a sneaky way they can ask

15:06

things without directly telling you what the

15:09

diagnosis is, but it makes it a little bit more—

15:16

All right, again, some discrepancy on this one.

15:18

I think partly because of the way the question is asked,

15:21

but in my experience, I took boards not too long ago,

15:24

and this is sort of the way that they ask things.

15:27

Um, so the correct answer is congenital, um,

15:32

because the answer is congenital pulmonic stenosis.

15:35

So this is sort of an Aunt Minnie radiograph

15:37

that you want to kind of burn into your head.

15:39

Um, and it results in asymmetric enlargement of

15:43

just the left and the main pulmonary artery, whereas

15:45

the right pulmonary artery looks pretty normal.

15:48

Um, and this is due to the, um, the jet or

15:53

the flow asymmetrically hits the left pulmonary

15:56

artery, making it larger compared to the right.

15:59

Um, and you can see that there's

16:01

significant right ventricular hypertrophy.

16:04

Um, and so this is just sort of a classic radiograph

16:06

that you need to burn in the back of your mind.

16:09

It's valvular congenital

16:10

pulmonic stenosis is the most common.

16:12

Um, and again, the next step would be getting an

16:15

MRI phase contrast rather than looking for the Qp:Qs.

16:19

Here, we could look at the flow, um, the mean pressure

16:22

gradient, and the peak velocity to assess the degree

16:26

or severity of the congenital pulmonic stenosis.

16:29

Treatment is balloon valvuloplasty,

16:32

surgical valvotomy, or valve replacement.

16:36

All right.

16:37

Case 11.

16:40

Where is the lesion located?

16:47

Perfect.

16:47

All right.

16:48

The majority of people said pleural,

16:49

which is the correct answer.

16:55

And this is a fibrous tumor of the pleura.

16:57

So the majority of them will

16:59

be indolent and sort of benign.

17:01

A minority can be locally aggressive.

17:03

Um, they can invade adjacent structures

17:05

and will have increased FDG uptake.

17:07

Um, and they arise from the visceral pleura

17:10

most commonly. Again, a minority can metastasize

17:14

to the pleura of the lung or the liver.

17:16

I think we had a question about

17:18

associated paraneoplastic syndromes.

17:20

So it was obviously a fibrous

17:21

tumor of the pleura, but it said,

17:23

um, you know, what is the associated,

17:26

uh, paraneoplastic syndrome?

17:28

So hypoglycemia related to insulin-like

17:31

growth factor—that's a common one you'll hear

17:33

about—hypertrophic osteoarthropathy, and then

17:37

hypercalcemia related to parathyroid-like hormone.

17:40

So just kind of remember these three things,

17:43

and then obviously the management would be resection.

17:48

All right.

17:48

Case 12.

17:50

What is a common presenting symptom?

17:57

Perfect.

17:57

All right.

17:58

The vast majority got this one correct.

18:00

So the correct answer is hemoptysis.

18:05

So this is a mycetoma, or a fungus ball,

18:08

which fills a preexisting cavity, whether

18:10

it's from TB, sarcoidosis, bronchiectasis,

18:14

cystic fibrosis, emphysema. And sputum

18:17

culture most commonly shows aspergillus.

18:20

Um, and it results in hemoptysis because it erodes the

18:24

adjacent blood vessels within the lung tissue.

18:27

And so treatment is directed

18:29

toward, um, the fungus itself.

18:33

Um, but in the case of massive hemoptysis,

18:35

bronchial artery embolization or even

18:36

surgical resection can be considered.

18:39

I don't really think that they would ask management

18:41

on that, but just, uh, knowing that it can

18:44

present with hemoptysis, I think, is important.

18:49

All right.

18:50

This is kind of a softball.

18:52

What is the best diagnosis?

18:59

All right, perfect.

19:00

So the vast majority got this correct as well.

19:03

Fibrosing mediastinitis.

19:05

So we can see, uh, right

19:07

hyaluronic soft tissue thickening with calcification.

19:10

It often, um, is kind of right-sided.

19:13

Um, and it can be from TB in the developing world.

19:17

Um, in the Midwest, where I am,

19:20

histoplasmosis is the vast majority.

19:22

Um, but IgG4 and even idiopathic causes

19:26

can also result, and typically, it causes

19:29

occlusion of the pulmonary veins first, um,

19:32

then the bronchi, and then the arteries.

19:34

And the treatment is typically with

19:36

stents, uh, for the veins and the airways.

19:44

All right.

19:44

Case number 14.

19:46

This was a 32-year-old woman with a history of asthma.

19:49

And if they're going to tell you

19:50

a history, it's probably relevant.

19:52

So pay attention to that.

19:55

And what is the best next step?

20:02

Perfect.

20:02

All right.

20:02

The majority got this correct.

20:04

The correct answer is steroids.

20:08

And so, this is a case of chronic eosinophilic pneumonia.

20:12

Imaging-wise, it looks the same as organizing pneumonia,

20:15

but on pathology,

20:17

they'll notice more eosinophils.

20:20

And the only real way you'd be able to tell

20:23

this by imaging is the history of asthma.

20:25

So asthma is chronic eosinophilic pneumonia, and it's

20:29

managed the same way as organizing pneumonia but tends

20:32

to be kind of peripheral, ground-glass consolidation,

20:35

um, and so steroids is the primary management.

20:39

All right, here is the next case: a 49-year-old

20:41

woman presenting, uh, with dyspnea.

20:44

What is the most likely cause?

20:51

All right, perfect.

20:52

So the majority got this one correct.

20:55

Um, the correct answer is scleroderma.

21:00

Um, and you can see the other answers,

21:01

442 00:21:03,150 --> 00:21:05,470 rheumatoid arthritis is a connective tissue disease,

21:05

but it more commonly presents with a UIP pattern.

21:08

Um, aspiration doesn't typically

21:10

cause, uh, fibrosis in and of itself.

21:13

Um, and so this is sort of a classic

21:16

NSIP pattern.

21:18

Um, we can see basilar-predominant ground-glass

21:21

reticulation and traction bronchiectasis.

21:24

Uh, no real honeycombing here.

21:27

And you can see it's relatively symmetric

21:29

and homogeneous within the lung bases.

21:33

Um, it can be idiopathic or secondary to other

21:35

processes, including other, uh, connective

21:38

tissue diseases—except rheumatoid arthritis,

21:41

which typically will have a UIP pattern.

21:43

So I think that kind of makes it a high-yield point.

21:47

Um, and I think just burning these images and

21:50

knowing how to differentiate them and maybe

21:52

even looking at them on a chest radiograph,

21:55

um, would be useful.

21:57

So see how the UIP pattern is a

21:59

little bit more heterogeneous?

22:01

It doesn't look quite the same.

22:02

We've got areas of more involved lung

22:05

directly adjacent to relatively spared lung.

22:08

Um, we can see some honeycombing.

22:10

So this is a very classic look

22:11

for usual interstitial pneumonia.

22:13

It's commonly seen in older men,

22:16

and the treatment is antifibrotics.

22:18

Nonspecific interstitial pneumonia

22:20

is the one we just talked about.

22:21

There's more ground-glass.

22:22

It tends to be more homogeneous.

22:24

Um, they'll have—

22:26

You'll hear of subpleural sparing. Um, you can see

22:29

in contrast to the UIP, which directly abuts the

22:31

pleura, the fibrosis. You can see the traction

22:34

bronchiectasis, and even the fibrosis, um, isn't all

22:37

located right at the subpleural or pleural area.

22:41

So that's kind of relative subpleural sparing.

22:43

And like we mentioned, it can be idiopathic or

22:46

related to other connective tissue diseases.

22:48

And depending on what the underlying cause is,

22:50

um, the treatment will be based on that, but it's

22:52

mostly dependent on steroids and immunosuppressants.

22:56

And then lastly, fibrotic hypersensitivity pneumonitis.

22:59

So this tends to be—have a different distribution,

23:01

with more mid and anterior lung involvement.

23:04

So they may even show, you know, a chest radiograph of

23:07

somebody with fibrotic HP and ask you to differentiate,

23:10

you know, between these two or at least three.

23:13

And just because it's upper lung

23:15

predominant, you should think fibrotic HP.

23:17

Um, and you'll hear people talk about

23:19

the three-density or head-cheese sign.

23:21

And that just refers to kind of the

23:23

three different densities we see.

23:24

So we can see relatively normal lung,

23:26

and then some areas of ground-glass and reticulation,

23:29

and then some areas of focal air trapping.

23:32

And it tends to be this kind of very lobular air

23:34

trapping, um, which should make you think fibrotic

23:38

hypersensitivity pneumonitis. And this, unlike

23:40

the other two, is an inhalational exposure.

23:43

So it'll be somebody that, you know, has

23:45

birds in their house, or molds, or a hot tub,

23:49

or has been exposed to chemicals at work.

23:52

Um, and so I think burning these three pictures

23:54

into your mind and then kind of recognizing the, uh,

23:57

causes and treatments would be high-yield.

24:02

All right.

24:03

Moving on.

24:03

A 38-year-old man with shortness of breath.

24:07

And what is the best next step in management?

24:16

All right.

24:16

Perfect.

24:17

92% percent of people got this one correct.

24:19

Smoking cessation.

24:20

That was probably a little bit

24:22

too obvious for the answer.

24:24

Um, but this is a very classic look for, uh,

24:27

Langerhans cell histiocytosis or eosinophilic, um,

24:32

granulomatosis, and the answer is smoking cessation.

24:34

So, uh, this is typically seen in young adult smokers,

24:38

male, um, and it's characterized as these bizarre

24:41

shaped cysts, often with some scattered nodules,

24:45

and it's due to a peribronchial proliferation of Langerhans

24:48

cells. And these nodules then cavitate and can

24:51

become thick- and thin-walled, forming these bizarre shapes.

24:55

And it is typically reversible with smoking cessation.

25:00

And patients often have pulmonary hypertension

25:03

due to a small vessel vasculopathy.

25:06

Um, and just being able to distinguish

25:07

it from other cystic lung diseases.

25:09

So, LAM, um, is typically more uniform cysts.

25:14

It's seen in younger women.

25:15

Um, LIP is classically associated with Sjögren's.

25:20

Um, and they just look pretty different.

25:23

So I think just recognizing these bizarre

25:25

shapes, this upper lung predominant pattern,

25:27

they're going to be a young adult male smoker.

25:32

All right.

25:33

Case 17.

25:35

What is the most likely cause?

25:41

All right.

25:42

This one was a little bit tricky.

25:43

So we already had a fibrous tumor of the pleura.

25:46

So I don't love that.

25:48

Um, you can see there is some pleural thickening and then

25:52

this kind of rounded opacity in the right lower lobe.

25:55

So this is a good look for rounded atelectasis.

25:58

And you can see that this is only unilateral.

26:01

So most likely it's either from prior

26:04

infection like an empyema or prior hemothorax.

26:07

Here we can see the patient had,

26:09

um, some— had a prior CABG.

26:12

And so this was likely a sequela of hemothorax,

26:15

561 00:26:16,390 --> 00:26:18,550 um, and resulted in some pleural thickening

26:18

and a little bit of rounded atelectasis.

26:21

So the answer was hemothorax.

26:24

So unilateral, you think about hemothorax,

26:26

empyema, like we mentioned. If it's

26:28

kind of a large, obviously malignant,

26:31

um, should be at the top of your diff.

26:32

And then, pleurodesis would kind of be a little bit

26:33

570 00:26:35,350 --> 00:26:37,620 more nodular and sometimes hyperdense.

26:38

Um, asbestos exposure tends to be bilateral.

26:42

And then again, kind of the classic

26:44

appearance of rounded atelectasis.

26:45

That comet tail shape, and then you'll

26:48

get curving of the vessels and bronchi

26:51

into that area.

26:53

All right.

26:54

Case 18 is a 28-year-old, status

26:57

post-stem cell transplant.

27:00

What is the best diagnosis?

27:07

Perfect.

27:07

All right.

27:07

The majority got this correct.

27:09

The correct answer is bronchiolitis obliterans.

27:13

So here we can see an inspiratory

27:16

and an expiratory image.

27:17

You can identify the expiratory image by

27:20

the flattening of the posterior trachea.

27:22

Um, and then you can see, um, all these areas of

27:26

geographic air trapping. So we refer to it

27:29

as mosaic attenuation on the inspiratory.

27:32

It's a little bit tougher to appreciate on the

27:34

inspiratory, but, kind of, you can see this area where

27:38

it becomes more obvious on the expiratory, um,

27:42

and then compared to the more normal lung, which becomes

27:45

more dense and, uh, loses volume on the expiratory.

27:49

And so, this can have a number of different

27:52

causes and results from progressive

27:54

narrowing or fibrosis of the small airways.

27:57

And so, it's an obstructive lung disease.

27:59

So you'll see a decrease in FEV1.

28:02

Um, and so in post-lung transplant patients,

28:05

we call it chronic lung allograft dysfunction or CLAD.

28:09

In allogeneic stem cell transplant,

28:11

we call it graft-versus-host disease.

28:14

Um, but it can also be from, you know, post-infectious

28:16

like in Swyer-James that we saw earlier, um, often

28:20

from adenovirus or mycoplasma and even other

28:24

disease processes like rheumatoid arthritis,

28:27

IBD, or diffuse neuroendocrine cell

28:31

hyperplasia, and some medications and drugs.

28:36

All right, case number 19.

28:39

What is the most likely diagnosis?

28:46

All right, perfect.

28:48

A slight majority got this one correct.

28:50

The correct answer is granulomatosis

28:52

with polyangiitis or Wegener's.

28:55

And this kind of brings up the classic

28:57

differential for tracheal narrowing.

29:00

So we have, uh, two things that, kind of, cause circumferential

29:04

thickening of the trachea, and the first being

29:07

granulomatosis with polyangiitis, which is what we saw.

29:10

Um, and then amyloid is the other that we think

29:13

about, which tends to be a little bit more

29:15

nodular and calcified compared to, uh, Wegener's.

29:20

And then the two that spare the posterior membrane

29:23

are relapsing polychondritis.

29:25

They can have calcification or not.

29:28

Sometimes it just looks like smooth thickening.

29:30

Um, and then TPOP.

29:32

And this one, again, tends to be a little bit more

29:35

irregular, nodular, and calcified, but in contrast

29:38

to amyloid, which involves the posterior membrane,

29:41

TPOP does not. And it's easy to remember that

29:44

these two are circumferential because they're

29:46

both systemic processes, um, whereas these two

29:49

are, um, primarily just tracheal processes.

29:55

All right, here is a 42-year-old female with a dry cough.

30:00

What is the distribution of micronodularity?

30:08

Perfect.

30:08

All right.

30:09

The vast majority got this correct.

30:11

So the correct answer is perilymphatic.

30:15

So this was a case of sarcoidosis,

30:17

um, which is non-caseating granulomas.

30:19

Here you can see some symmetric, uh, mediastinal

30:23

and bilateral hilar lymphadenopathy and then extensive

30:26

perilymphatic nodularity, kinnd of along the

30:29

bronchovascular bundles and the fissures.

30:32

Um, and it tends to be upper lung predominant.

30:36

Sometimes you'll hear people talk about

30:37

the galaxy sign, where you'll have, kind of,

30:40

um, nodules surrounding a larger nodule.

30:43

Um, and it can also present with small airways disease,

30:46

again with that mosaic attenuation and air trapping.

30:49

Um, and then, uh, in some cases, it can lead

30:51

to fibrosis, which again will be upper lung

30:53

predominant, kind of, retraction of the hila.

30:56

They'll often show you some

30:57

perilymphatic nodularity with it.

30:59

Um, and in terms of the differential, um, other

31:03

granulomatous processes like infections

31:06

or inflammation can result in a similar imaging

31:09

appearance, or even lymphangitic carcinomatosis,

31:12

um, often seen with breast cancer, lung cancer, or stomach.

31:14

Um, so just something to keep in mind.

31:19

All right.

31:19

Case 21, a 65-year-old non-smoker

31:22

presenting for progressive dyspnea.

31:25

And the question is, what is the best diagnosis?

31:29

You can see the vast majority of questions

31:31

are "What is the best diagnosis?" and then a

31:33

few are sort of "Tell me something else about

31:36

the disease" or the next best treatment.

31:44

Okay, perfect.

31:45

Most people got this one correct.

31:46

The correct answer is hypersensitivity pneumonitis.

31:50

Um, and if you remember, we said a non-smoker.

31:55

So you can see, uh, kind of, diffuse centrilobular

31:57

micronodules, upper lung predominant.

32:00

Um, so if this was a smoker, uh, imaging-wise,

32:04

you would think respiratory bronchiolitis.

32:05

It looks very similar.

32:07

Um, but since we said it was a non-smoker,

32:10

hypersensitivity pneumonitis is the correct answer.

32:13

And this kind of leads us down to

32:15

the micronodule, uh, discussion.

32:17

So perilymphatic nodules, we kind of hit with that,

32:21

uh, granulomatous infection, inflammation, sarcoid.

32:25

Um, anytime I think of sarcoid,

32:26

I also think of silicosis.

32:28

Um, and then, now we're kind of focusing

32:31

on the centrilobular pattern.

32:33

So, uh, ground glass—again, a non-smoker, it will

32:35

be hypersensitivity pneumonitis, and then,

32:38

in a smoker, it will be respiratory bronchiolitis.

32:41

And then random will be, uh, some distribution

32:43

of both of these.

32:45

So they'll abut the pleura and fissures, and then

32:48

some will be, kind of, centrilobular.

32:50

And this is often hematogenous infection or METS.

32:53

So think about thyroid, RCC,

32:56

chorio, um, or TB, histo, varicella.

33:00

I think they had a few questions showing

33:02

calcified nodules, and the answer was varicella.

33:06

All right.

33:06

Case 22, what is the normal, uh,

33:10

structure the arrow is pointing to?

33:17

Okay, perfect.

33:18

The slight majority, uh, got the correct

33:20

answer, which is the left upper lobe bronchus.

33:24

Um, and we'll go through one more.

33:27

Um, what is this normal structure pointing to?

33:34

The lateral radiograph anatomy

33:36

just makes for high-yield.

33:39

Easy questions.

33:44

And on the actual exam, they actually gave you

33:46

an arrow and said, "Drag the arrow or point to,"

33:50

and then would say what they wanted you to show.

33:53

Um, so this one, uh, only, uh, 29% got the

33:58

correct answer, which is the bronchus intermedius.

34:01

So here you can see this kind of U-shaped is the right

34:03

upper lobe bronchus, and then we have the bronchus

34:06

intermedius, and we're looking at kind of the posterior

34:09

wall. Um, and then here, this rounded structure is

34:12

the left upper lobe bronchus. Um, and so I think

34:15

those are kind of the high-yield, hilar structures.

34:18

Then we have the pulmonary vein-artery confluence. Um,

34:23

and so the correct answer was bronchus intermedius.

34:28

All right, I think we hit all of those there.

34:31

All right.

34:32

Last case, which valve is repaired?

34:36

Hopefully, you can see.

34:43

Some of the images on the actual

34:45

exam also were a little questionable.

34:49

So this is probably an accurate representation.

34:58

All right, perfect.

34:59

So 60% got the answer

35:00

correct, which is tricuspid.

35:03

Um, I think it's helpful that the——to remember

35:05

that the tricuspid valve often points up to the

35:07

left shoulder, shown here, whereas the mitral

35:10

valve will point up to the right shoulder.

35:13

Um, and so even if the patient is a little bit rotated,

35:15

like they are here, you can differentiate the tricuspid

35:19

from the mitral based on, sort of, the way that it points.

35:25

And here is just kind of a reminder,

35:27

um, to burn in the back of your head.

35:29

Here was the tricuspid.

35:30

Here, you can see how the mitral valve

35:32

sort of points up toward the right shoulder,

35:34

whereas the tricuspid points up to the left.

35:37

Um, and then the pulmonary valve is sort of

35:39

the highest, most anterior valve.

35:45

All right, so I think that was kind of a

35:47

rapid-fire 25 high-yield, kind of, reviewing

35:50

um, broad topics that they like asking about.

35:53

And hopefully, giving you idea of how they can

35:55

ask things in a little bit more of a tricky way.

35:59

Um, but let me know if you guys have any questions,

36:03

and we are very happy that you guys joined us.

36:07

Thank you so much for that case review.

36:09

Appreciate that.

36:11

At this time, we will open the floor for

36:13

questions from the audience, and you can

36:15

submit those through the Q&A feature,

36:17

if you'd like.

36:19

There's a question there right now.

36:21

Um, what was the diagnosis on question 14, on case 14?

36:27

14? Let's see.

36:30

14—chronic eosinophilic pneumonia.

36:35

So it looks the same as organizing pneumonia,

36:37

but we gave you the history of asthma.

36:40

Um, and it was kind of peripheral

36:42

ground-glass opacities.

36:44

Um, and so the answer was chronic eosinophilic

36:46

pneumonia, and you would treat with steroids.

36:49

Okay, I think we'll wrap there.

36:51

Thank you so much for this case review.

36:53

We really appreciate you being here, Dr. Marquis.

36:55

Thanks, everybody.

36:56

Have a good night.

36:57

Thanks everyone else for participating.

36:59

You can access the replay of previous reviews

37:02

and this review by creating a free account.

37:05

Be sure to join us for our next

37:07

review in the series on Monday, March 17th with Dr. Navid Farajii.

37:11

He'll lead us in a review of MSK imaging cases.

37:15

You can register for that at the link

37:16

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37:18

social media for updates on future meetings.

37:21

Thanks again for learning with us,

37:22

and we'll see you soon.