Chest X-Rays

Question 1

What is the most common reason for apparent mediastinal widening on chest X-ray?

Answer 1

Technical factors, especially patient rotation.

Question 2

What are the main true pathological causes of mediastinal widening?

Answer 2

Thoracic aortic aneurysm, lymphoma, retrosternal goitre, teratoma, thymic tumours.

Question 3

What imaging helps distinguish anterior vs posterior mediastinal masses?

Answer 3

Lateral chest X-ray, though CT is now preferred.

Question 4

What is the most common cause of lobar collapse in older adults?

Answer 4

Lung cancer.

Question 5

What are other common causes of lobar collapse?

Answer 5

Asthma (mucous plugging) and foreign body aspiration.

Question 6

What chest X-ray signs suggest lobar collapse?

Answer 6

Tracheal deviation toward the collapse, mediastinal shift toward the collapse, elevation of the hemidiaphragm.

Question 7

What are the key infectious causes of cavitating lung lesions?

Answer 7

Lung abscess from Staph aureus, Klebsiella, or Pseudomonas; tuberculosis.

Question 8

What are the key non-infectious causes of cavitating lung lesions?

Answer 8

Squamous cell lung cancer, Wegener’s granulomatosis, pulmonary embolism, rheumatoid arthritis, aspergillosis, histoplasmosis, coccidioidomycosis.

Question 9

What CXR features indicate pulmonary oedema?

Answer 9

Interstitial oedema, bat-wing perihilar shadowing, upper lobe diversion, Kerley B lines, pleural effusions, cardiomegaly if cardiogenic.

Question 10

Which cancers commonly metastasise to the lungs?

Answer 10

Breast, colorectal, renal cell, bladder, and prostate cancer.

Question 11

What are ‘cannonball metastases’?

Answer 11

Multiple round, well-defined pulmonary metastases, most often from renal cell cancer but also choriocarcinoma or prostate cancer.

Question 12

When is calcification seen in lung metastases?

Answer 12

Rarely; most commonly in osteosarcoma or chondrosarcoma metastases.

Question 13

What are the main causes of white shadowing on a chest X-ray?

Answer 13

Consolidation, pleural effusion, collapse, pneumonectomy, tumours, pulmonary oedema.

Question 14

How does tracheal deviation help interpret a hemithorax ‘white-out’?

Answer 14

Pulled toward: pneumonectomy, total collapse, pulmonary hypoplasia. Central: consolidation, pulmonary oedema, mesothelioma. Pushed away: pleural effusion, diaphragmatic hernia, large thoracic mass.

Question 15

Where should the tip of an NG tube be located on a chest X-ray?

Answer 15

Below the diaphragm within the stomach.

Question 16

Why is checking NG tube position essential before use?

Answer 16

Misplacement (e.g., into bronchial tree) can cause aspiration pneumonia and death.

Question 17

Who often must confirm NG tube placement before use?

Answer 17

A radiologist, according to many hospital policies.