Westermark sign: Difference between revisions

In [[chest X-rayradiograph|chest radiography]], the '''Westermark Sign''', is a [[sign (medicine)|sign]] that represents a focus of [[oligemia]] ([[vasoconstriction]]) seen distal to a [[pulmonary embolism|pulmonary embolus]] (PE).<ref>{{cite journal | author = Ray J | title = Westermark sign and suspected pulmonary embolism. | journal = Can J Cardiol | volume = 19 | issue = 3 | pages = 317; author reply 317 | year = 2003 | pmid = 12680403}}</ref> While the chest x-ray is normal<ref>Introduction to Chest Radiography. http://www.med-ed.virginia.edu/courses/rad/cxr/index.html</ref> in the majority of PE cases, the Westermark sign is seen in 2% of patients.<ref>{{cite journal | author = Worsley D, Alavi A, Aronchick J, Chen J, Greenspan R, Ravin C | title = Chest radiographic findings in patients with acute pulmonary embolism: observations from the PIOPED Study. | journal = Radiology | volume = 189 | issue = 1 | pages = 133–6 | year = 1993 | pmid = 8372182}}</ref>

The Westermark sign, like [[Hampton's hump]] (a wedge shaped, pleural based consolidation associated with [[lung|pulmonary]] [[infarction]]), has a low [[sensitivity (test)|sensitivity]] (11%) and high [[specificity]] (92%) for the diagnosis of pulmonary embolusembolism.<ref>Gurney J. CT: Diagnosis of Pulmonary Embolism. chestx-ray.com. Available at: