Chest X-rays

Question 1

Steps for interpreting a chest X-ray

Answer 1

1. Lung fields - compare upper, mid and lower zones
2. Hilum
3. Heart - normal shape and size
4. Mediastinum outlines
5. Diaphragm - right should be higher
6. Costophrenic angles - should be well defined
7. Trachea - should be central
8. Bones and soft tissues - fractures, surgical emphysema, perforation, nodes

Question 2

CXR features of a pneuothorax

Answer 2

White line of visceral pleura parallel to chest wall
No lung markings lateral to the line
Lung fields apprear darker than normal
There may be associated rib fractures

In tension pneumothorax there is mediastinal shift away from the side of the pneumothorax.

Question 3

CXR finding in emphysema

Answer 3

Hyperinflation of the lungs
Reduced vascular markings
Bullae may be present

Question 4

How can you tell if lungs are hyperinflated on CXR?

Answer 4

Anterior end of 6th rib and posterior end of 10th rib should be visible above the diaphragm
More ribs visible = hyperinflation

Question 5

CXR findings in complete lung collapse

Answer 5

All lung fields are opaque due to non-aerated lung
Trachea and heart is shifted towards the opacity.

Cancer is the commonest cause of lung collapse

Question 6

CXR findings in pleural effusion

Answer 6

Lung fields are opaque
Trachea and heart is shifted away from the opacity
Obscures the hemidiaphragm and costophrenic angle
May see a meniscus

Question 7

CXR findings in a patient with consolidation

Answer 7

Accumulation of fluid/cells in the alveoli causes airspace shadowing.

Affected lung parenchyma becomes dense and white, airways remain black (air bronchogram)

Question 8

What is the silhoutte sign?

Answer 8

Seen in CXR indicates airspace disease e.g. consolidation which obscures the borders of the heart.

Question 9

CXR finding in sarcoidosis

Answer 9

bilateral hilar enlargement

parenchymal shadowing

Question 10

How can you localize disease with silhouette sign?

Answer 10

Left diaphragm disappears - left lower lobe
Right diaphragm - right lower lobe
Left cardiac border - left upper lobe
Right cardiac border middle lobe

Question 11

DDx of bilateral hilar lymphadenopathy

Answer 11

lymphoma
TB
Bronchial carcinoma
Sarcoidosis