Signs in pulmonary embolism
Westermark sign is a focal oligemia of the lung due to occlusion of a branch pulmonary artery due to pulmonary embolism. The vessel proximal to the occlusion is dilated.
Hampton’s hump is a peripheral pleural based wedge shaped lung opacity due to pulmonary infarction in a case of pulmonary embolism.
Knuckle sign is the abrupt cut off of a pulmonary artery branch due to pulmonary embolism.
McConnell’s sign is akinesia of right ventricular mid-free wall with sparing apex seen in acute pulmonary embolism. This finding has a sensitivity of 77% and specificity of 94% [Am J Cardiol. 1996;78:469-73]