Chest Xray: Abnormalities

Question 1

What is the most likely cause of this tracheal displacement?

Answer 1

The trachea is shifted left of the midline.

Due to a soft tissue mass mainly to the right of the trachea
? mediastinalthyroid enlargement?

Question 2

Bilateral hilar enlargement on chest xray should raise the suspicion of?

What other signs would raise this suspicion?

Differential diagnoses?

Answer 2

Sarcoidosis

Particularly if there is evidence of paratracheal enlargement or lung parenchymal shadowing.

DD: lymphoma, metastatic disease, infection, pulmonary artery hypertension

Question 3

Asymmetric hilar enlargement should raise the suspicion of?

Answer 3

Metastatic disease.

Question 4

What can be the cause of ‘consolidation’ ?

Answer 4

pus (pneumonia), fluid (pulmonary oedema), blood (pulmonary haemorrhage), cells (cancer)

It does not always mean infection!

Question 5

Describe the phenomenon of an ‘air-bronchogram’

Answer 5

If an area of lung is consolidated (dense and white), the larger airways are often spared (remain black/low density).

This is an ‘air bronchogram’ and is a characteristic sign of consolidation!

Question 6

Most common cause of a pneumothorax?

Answer 6

Trauma where the visceral pleura is lacerated by a fractured rib leading to air in the pleural space!

Question 7

When do you know its a tension pneumothorax and what . is the clinical significance of this?

Answer 7

When the trachea and mediastinal structures are displaced contralaterally, splaying of the ribs, flattening of the ipsilateral diaphragm.

**haemodynamic compromise: tachycardia, hypotension

Question 8

Causes of pleural plaques

Answer 8

• Asbestos exposure (can be calicified (benign))
• Previous infection
• TB (unilateral)

Can be a mesothelioma

Question 9

Malignant cause of pleural thickening?

Answer 9

mesothelioma

Question 10

What are the causes of costo-phrenic angle blunting?

Answer 10

• Pleural effusions
• Lung disease in that region
• Lung hyperexpansion

Question 11

What is this and why do we worry about it?

What’s Rigler’s sign?

Answer 11

Pneumoperitoneum: free intra-abdominal airunder the diaphragm

This is a sign of bowel perforation!
Usually due to an ulcer

Rigler’s sign (blue lign) is where black air can be seen on both sides of the bowel wall

Question 12

Causes of a raised hemi-diaphragm?

Answer 12

• Damaged phrenic nerve
• Lung disease causing volume loss
• Diaphragmatic hernia
• Diaphragm trauma

Question 13

If the CTR is enlarged and you suspect heart failure, what other signs can you look for on chest xray?

Answer 13

1. Upper zone vessel enlargment (should be smaller then the lower one vessels)
2. Pulmonary oedema: interstitial oedema (Kerley B lines)
3. Pulmonary oedema: septal oedema (airspace/batwing shadowing)
4. Pleural effusions

Question 14

Why and when do we get Kerley B lines?

Answer 14

Kerley B or ‘septal’ lines are caused by thickening of the interlobular septa which seperate the secondary lobules of the lungs due to interstitial oedema and should increase suspicion of heart failure

Question 15

Signs of left atrial enlargement on chest xray?

Answer 15

• A double right heart border
• Bulging of the left heart border
• Splaying of the carina to greater then 90 degrees

Question 16

What is this?

Answer 16

thoracic aortic aneurysm!

• Sternal wires and aortic valve prosthesis (arrowhead)
• Massive aortic knuckle (red line)
• Displaced trachea (arrow)
• Widened, tortuous descending aorta (blue lines)

Question 17