THORACIC Section 11: Alveolar

Question 1

Condition where surfactant accumulates in the alveoli and terminal bronchioles.

Answer 1

Pulmonary Alveolar Proteinosis (PAP)

Question 2

Secondary causes of Pulmonary Alveolar Proteinosis (PAP)

Answer 2

Cancer or inhilation (Silico-proteinosis)

Question 3

Pulmonary Alveolar Proteinosis are at increased risk of what infection?

Answer 3

Nocardia. Can have Nocardia brain abscess.

Question 4

PAP associated disease in children (<age 1)

Answer 4

Alymphoplasia

Question 5

Describe the pattern and areas involved

Answer 5

Interlobular septal thickening and ground glass.
Typically central and symmetric, sparing the apices and costophrenic angles

Question 6

Causes of crazy paving appearance

Answer 6

C - COPD/Cancer/COVID
R - Respiratory distress (Acute)
A - Alveolar proteinosis
Z - Zipper (Lipoid pneumonia, So fat you cannot zip your pants)
Y - Y are you hemorrhageing? hahaha! -
P aving - PCP

Question 7

Describe the pattern

Answer 7

Interlobar septal thickening with GG

Question 8

CT scan appearance of Lipoid pneumonia

Answer 8

Low attenuation/fat density in the consolidation.

Question 9

Results from post obstructive process (cancer) causing build up of lipid laden macrophages

Answer 9

Endogenous Lipoid pneumonia

Question 10

Diagnosis?
Describe

Answer 10

Lipoid pneumonia
Fat Density in the consolidation

Question 11

When showed soft tissue window on lung CT, always think about these things!

Answer 11

fat lesion - think hamartoma or lipoid pneumonia

Question 12

When showed BONE window on lung CT, always think about these things!

Answer 12

Pulmonary microlithiasis.

Question 13

It’s not an active infection (as the name would suggest) but instead granulation tissue deposition within the alveolar spaces secondary to fibroblast proliferation.

Answer 13

Organizing Pneumonia

Question 14

Antibiotics wont work in this type of pneumonia. Respond well to steroids.

Answer 14

Organizing pneumonia

Question 15

Diagnosis?
Describe the pattern

Answer 15

Cryptogenic Organizing pneumonia

Reverse Halo

Patchy air space consolidation or GGO (90%), in a peripheral or peri-bronchial distribution (sometimes a perilobular/arcade-like pattern).

Question 15

Name conditions presenting as peripheral consolidations

Answer 15

Organizing pneumonia

Question 16

Consolidation around a ground glass center.

Answer 16

Reverse Halo (Atoll) Sign

Question 17

Classic sign of Oganizing Pneumonia

Answer 17

REverse Halo (Atoll) Sign

Question 18

Conditions were Reverse Halo Sign is seen

Answer 18

COVID
Organizing pneumonia

Question 19

Describe?
Diagnosis?

Answer 19

Classic Look on CXR:
* Bilateral
* Non-segmental Consohdation
* Favoring the outer 2/3 o f the lungs (peripheral)

Eosinophilic Pneumonia

Question 20

CT Findings of Chronic Eosinphilic Pneumonia

Answer 20

Peripheral GGO or consolidation.
Upper lobes tend to be favored.

Question 21

Name this pneumonia

Can be idiopathic or associated with a known antigen. Peripheral eosinophilia (blood test) is usually present. An asthma history is found in about 50% of cases. It looks exactly like COP (both can present as peripheral consolidations). When you say COP you should say this one too (some people think it’s the same disease as COP).

Answer 21

Chronic Eosinophilic Pneumonia

Question 22

HALO SIGNS:

-Nodule with ground glass around it
-Represents hemorrhage / invasion into surrounding tissues

Answer 22

Halo

Question 23

SIGNS:

Central ground glass with rim of consolidation

Answer 23

Reverse HALO (Atoll)

Question 24

Halo sign is seen in what conditions?

Answer 24

• Invasive Aspergillosis (Classic)
• Other Fungus
• Hemorrhagic Mets
• Adenocarcinoma in Situ (BAC)
• Wegeners

Question 25

Reverse Halo (Atoll) Sign is seen in what conditions?

Answer 25

Cryptogenic Organizing Pneumonia (CLASSIC)
COVID
TB
Pulmonary Infarct
Invasive Fungal and Wegeners
** these can also be seen with regular Halo - COVID

Question 26

This is actually common. It’s caused by inhaled organic antigens. It has acute, subacute, and chronic stages. Most o f the time it’s imaged in the subacute stage.

Answer 26

Hypersensitivity Pneumonitis

Question 27

Patchy ground glass opacities. Ill-defined Centrilobular ground glass nodules (80%). Often has mosaic perfusion, and air trapping.

Answer 27

Subacute Hypersensitivity Pneumonitis

Question 28

Looks like UIP + Air trappins. You are gonna have traction bronchiectasis and air trapping.

Answer 28

Chronic Hypersensitivity Pneumonitis

Question 29

Diagnosis?
Describe

Answer 29

Hypersensitivity pneumonitis
Headcheese
Juxtaposition of 3 different regions
Groundglass + Air Trapping + Normal Lungs

Question 30

Explanation of Headcheese apperance of Hypersensitivity pneumonitis

Answer 30

Infiltrative process (ground glass)
Obstructive process (mosaic attenuation / air-trapping)