Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Westermark sign
Introduction
Overview
Overview
In chest radiography, the Westermark Sign, is a sign that represents a focus of oligemia (vasoconstriction) seen distal to a pulmonary embolus (PE).[1] While the chest x-ray is abnormal in the majority of PE cases, the Westermark sign is seen in only 2% of patients.[2]
The sign results from a combination of:
- the dilation of the pulmonary arteries proximal to the embolus and
- the collapse of the distal vasculature creating the appearance of a sharp cut off on chest radiography.
Sensitivity and specificity
Sensitivity and specificity
The Westermark sign, like Hampton’s hump (a wedge shaped, pleural based consolidation associated with pulmonary infarction), has a low sensitivity (11%) and high specificity (92%) for the diagnosis of pulmonary embolus.[3]
References
References
- ↑ Ray J (2003). “Westermark sign and suspected pulmonary embolism”. Can J Cardiol. 19 (3): 317, author reply 317. PMID 12680403.
- ↑ Worsley D, Alavi A, Aronchick J, Chen J, Greenspan R, Ravin C (1993). “Chest radiographic findings in patients with acute pulmonary embolism: observations from the PIOPED Study”. Radiology. 189 (1): 133–6. PMID 8372182.
- ↑ Gurney J. CT: Diagnosis of Pulmonary Embolism. chestx-ray.com. Available at: http://www.chestx-ray.com/Lectures/PulmEmbLecture/PulmEmbolus.pdf. Accessed on: November 13, 2006.
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Editor-In-Chief: Template:Search infobox C. Michael Gibson, M.S., M.D. [1]