CXR: Mediastinal Shift

Question 1

Which blood vessels are found in the normal mediastinum? (5)

Answer 1

Left brachiocephalic vein
Right brachiocephalic vein
Brachiocephalic artery
Left carotid artery
Left subclavian artery

Question 2

On a CT scan of the mediastinum, describe how you would distinguish the blood vessels.

Answer 2

Veins in front
Arteries at the back
Arteries in the order of the branches from the aortic arch

Question 3

On a CT scan of the mediastinum just above the heart, which 3 vessels are seen?

Where is each one located?

Answer 3

Ascending aorta (anterior)
Descending aorta (posterior)
Pulmonary artery trunk (middle)

Question 4

Describe the features of a pleural effusion on CXR. (4)

Answer 4

Meniscus sign
Blunting of costophrenic angle
Mediastinal shift AWAY from effusion
Displacement of heart

Question 5

Describe the features of pneumothorax on CXR. (3)

Answer 5

Pleural line within the thorax
No lung markings outside pleural line
Diaphragm depression

Question 6

What feature on CXR would indicate tension pneumothorax?

Answer 6

Mediastinal shift

Question 7

Describe the features of pneumothorax on a supine CXR. (4)

Answer 7

Deep costophrenic angle
Increased clarity of mediastinal border
Diaphragm depression
Visualisation of inferior surface of heart

Question 8

Describe the features of a lobar collapse on CXR. (7)

Answer 8

NO mediastinal shift
Tracheal displacement TOWARDS collapse
Displacement of lung fissures TOWARDS collapsed lobe
Golden’s reverse sign
Opacification of collapsed lobe
Veil-like opacification of affected hemithorax
Possible elevated hemidiaphragm (on affected side)

Question 9

What is Golden’s reverse sign?

What condition does it indicate?

Answer 9

Bulging of the oblique fissure medially

Lobar collapse

Question 10

What is the main cause of mediastinal shift with a lucent lung?

Answer 10

Pneumothorax

Question 11

What can commonly cause mediastinal shift TOWARDS an opaque, white lung? (2)

Answer 11

Collapse

Post pneumonectomy

Question 12

What can cause mediastinal shift AWAY from an opaque, white lung? (2)

Answer 12

Pleural effusion

Diaphragmatic hernia

Question 13

List 4 possible causes of bilateral lymphadenopathy on CXR.

Answer 13

Sarcoidosis
Lymphoma
TB
Malignancy

Question 14

Describe the features of an old pneumonectomy on CXR. (4)

Answer 14

Totally white lung
Surgical clips etc.
Mediastinal shift TOWARDS white lung
NO heart displacement

Question 15

How do you differentiate between lung collapse and consolidation of the lung?

Both will cause a white, opaque lung on CXR.

Answer 15

LUNG COLLAPSE:

• Collapsed/occluded bronchi
• Displaced fissures

CONSOLIDATION:

• Patent bronchi
• Normal shape/location of fissures BUT they are outlined in white

Question 16

Describe the features of a right upper lobe collapse on CXR. (2)

Answer 16

Horizontal fissure displaced superiorly

White lung at the apex

Question 17

Describe the features of a right middle lobe collapse on CXR. (4)

Answer 17

Loss of cardiac silhouette
Collapsed lung medially
Fuzzy, not solid opacification
Horizontal fissure displaced superiorly

Question 18

What sort of x-ray view is best used to view a right middle lobe collapse?

Answer 18

Lateral

Question 19

Describe the features of a right lower lobe collapse on CXR. (3)

Answer 19

Loss of diaphragm border
Collapses medially and inferiorly
Right middle lobe expands to take its place

Question 20

Describe the features of a left upper lobe collapse on CXR. (4)

Answer 20

Almost entire left lung seems to be affected
Hazy opacification of lobe
Loss of cardiac silhouette
Emphasis of the aortic arch (Luftsichel sign)

Question 21

Describe the features of a left lower lobe collapse on CXR. (3)

Answer 21

Loss of diaphragm border
Collapses medially and inferiorly
Left upper lobe expands to take its place

Question 22

Apart from pneumothorax, list 5 less common causes of mediastinal shift with a lucent lung.

Answer 22

Bullae
Rotation (technical defect)
Chest wall abnormalities
Pleural abnormalities
Vascular problems (e.g. pulmonary embolism)