Cases

Question 1

Interstitial Lung Disease Signs and DDx

Answer 1

Usual Interstitial Pneumonia

Fx on HRCT:

• Fine and coarse reticular opacities
• Predominance in basal and subpleural region.
• Honeycombing - Common
• Architectural distortion with traction bronchiectasis due to fibrosis (considered a very good differentiating feature from patients with NSIP).
• Ground-glass opacities : common but are usually less extensive than the reticular pattern.

DDx:

1. Chronic Hypersensitivity Pneumonitis
2. End stage Sarcoidosis
3. NSIP

Question 2

CXR: Interstial Lung Disease DDx

Answer 2

Lymphangitic Carcinomatosis:

Usually arises from adenocarcinomas such as:

• Breast; Lung; Stomach

Findings:

• 50% are unilateral (usu from bronchogenic Ca)
• Reticular / reticular-nodular opacification
• Kerley B Lines
• Pleural effusion

DDx: (these are also for interlobar septal thickening)

1. Pulmonary oedema
2. Sarcoidosis
3. Viral pneumonia
4. Lymphocytic interstitial pneumonitis (LIP)

Question 3

HRCT Interstial Lung Disease

Answer 3

Sarcoidosis

HRCT Fx:

Common Findings

• Small nodules in a perilymphatic distribution.
• Upper and middle zone predominance.
• Lymphadenopathy in left, right hila and paratracheal (Garland’s triad). Often with calcifications (egg shell).

Uncommon findings:

• Conglomerate masses in a perihilar location.
• Grouped nodules or coalescent nodlues surrounded by multiple satellite nodules (Galaxy sign)
• Nodules so small and dense that they appear as ground glass or even as consolidations (alveolar sarcoidosis).
• End-stage fibrosis(20% pts.). Permanent coarse linear opacities typically radiating laterally from the hilum into the adjacent upper and middle zones
• Architectural distortion +/- traction bronchiectasis
• Pleural effusion(s): usually small or moderate in size. Usually resolve within 2 - 3 months

Question 4

What is this Sign and DDx?

Answer 4

Crazy Paving

Refers to reticular opacificaties superimposed on areas of ground-glass opacity.

DDx:

1. Alveolar proteinosis
2. ARDS
3. Pneumonias: Bacterial / Acute interstitial /
4. acute respiratory distress syndrome
5. Pulmonary oedema
6. Pulmonary haemorrhage - diffuse
7. Alveolar microliathesis - calcified interlobular septa and multiple calcified nodules
8. PCP
9. Radiation pneumonitis
10. Cryptogenic organizing pneumonia (COP, formerly BOOP)
11. Mucinous bronchioloalveolar carcinoma
12. Sarcoidosis

Remember the “Ps”

• Alveolar Proteinosis
• Pneumonias: Bacterial / Acute interstial
• PCP
• Pulmonary oedema
• Pulmonary haemorrhage
• Radiation Pneumonitis

Question 5

59yr old with left arm pain on abduction

Answer 5

SUBCLAVIAN STEAL SYNDROME

This condition is due to stenosis of the subclavian artery resulting in “stealing” of blood to the arm by retrograde flow in the ipsilateral vertebral artery

The commonest cause is atherosclerotic disease. Other acquired causes include:

• Takayasu vasculitis
• Embolism
• Aortic dissection
• Radiation fibrosis
• Trauma

Further Management:

CT to identify:

• calcified atherosclerotic plaques
• Site and degree of stenosis.

Surgical or interventional radiology referral for:

• Balloon angioplasty +/- stent insertion or
• Surgical bypass.

Question 6

CXR: Hyperdense Nodules DDx

Answer 6

Healed Varicella Pneumonia

DDx:

• Pulmonary haemosiderosis (secondary to mitral stenosis)
• Metastatic disease (osteosarcoma, thyroid)
• Silicosis
• Repeated pulmonary haemorrhage (Goodpasture’s syndrome).
• Healed granulomata (histoplasmosis)
• Alveolar microlithiasis (case below)

Question 7

CXR: Lower Zone Fibrosis

Answer 7

DDx:

1. IPF (previous image)
2. Scleroderma
3. RA
4. Asbestosis
5. Drugs: Bleomycin