Chest radiograph signs of Pulmonary Embolism

Classic chest radiograph signs of pulmonary emboli include –

Signs of Pulmonary EmbolismFindings on X-Ray
1 ‘Westermark sign’ Regional oligaemia
2 ‘Palla sign’ Right descending pulmonary artery enlargement
3 ‘Fleishner sign’ Central pulmonary artery enlargement
4 ‘knuckle sign’ Abrupt pulmonary artery tapering

Westermark sign – regional oligaemia

Westermark sign is a sign that represents a focus of oligemia

  1. Dilation of the pulmonary arteries proximal to the embolus
  2. Collapse of the distal vasculature creating the appearance of a sharp cut off on chest radiography.
  3. Low sensitivity (11%) and high specificity (92%) for the diagnosis of pulmonary embolism

Palla sign – right descending pulmonary artery enlargement

Palla sign describes an enlarged right descending pulmonary artery which suggestive of an occlusion of a lobar or segmental pulmonary artery, or widespread occlusion of small arteries.

Fleischner sign – central pulmonary artery enlargement

Fleischner sign refers to a prominent central pulmonary artery that can be commonly caused either by pulmonary hypertension or by distension of the vessel by a large pulmonary embolus

Knuckle sign – abrupt pulmonary artery tapering

knuckle sign refers to the abrupt tapering or cutoff of a pulmonary artery secondary to a pulmonary embolus

Newsletter Signup

100% FREE ! Subscribe to our newsletter For Updates and New Publications in Medicine Question Bank.

Subscribe to our weekly newsletter below and never miss the latest Information. 

Medicine Questions, MCQs ,Viva questions, Image questions

100% FREE