DDX

Question 1

Central GGO

Answer 1

pulm edema
alveolar hemorrhage
PCP pneumonia
alveolar proteinosis

Question 2

Peripheral GGO

Answer 2

Organizing pneumonia
chronic eosinophilic pneumonia (upper lobe predominance)
atypical/viral pneumonia
pulm edema (noncardiogenic such as drug)

Question 3

Interlobular Septal Thickening -Smooth

Answer 3

pulm edema (MOST COMMON)
pulm hemorrhage
atypical pneumonia (esp PCP)
pulm proteinosis

Question 4

Interlobular Septal Thickening - Nodular/Irregular

Answer 4

Lymphangitic carcinomatosis

Sarcoidosis

Question 5

Centrilobular Nodules

Answer 5

Infectious

1. bronchopneumonia
2. atypical pneumonia

Inflammatory

1. hypersensitivity pneumonitis
2. respiratory bronchiolitis - interstitial lung disease
3. diffuse panchronchiolitis
4. silicosis

Question 6

Perilymphatic Nodules

Answer 6

sarcoidosis (most common)
pneuomoconioses
lymphangitic carcinomatosis

subpleural
peribronchovascular

Question 7

Random Nodules

Answer 7

Hematogenous mets
septic emboli
Langerhans cell histiocytosis

Question 8

Miliary pattern

Answer 8

disseminated TB
disseminated fungal infection
disseminated mets

Question 9

Tree in Bud

Answer 9

bacterial pneumonia
aspiration pneumonia
atypical pneumonia
aspergillus

Question 10

Lower Lobe Fibrotic Changes

Answer 10

UIP/IPF
NSIP
End stage abestosis (if pleural plaques are present)

Question 11

Upper Lobe Fibrotic Changes

Answer 11

End stage sarcoidosis
Chronic hypersensitivity pneumonitis
End stage silicosis