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The V-line: a sonographic aid for the confirmation of pleural fluid

Paul Atkinson12*, James Milne1, Osama Loubani3 and Glenn Verheul2

Author Affiliations

1 Dalhousie Medicine New Brunswick, 100 Tucker Park Road, Saint John, NB, E2L 4L5, Canada

2 Department of Emergency Medicine, Dalhousie University, Saint John Regional Hospital, 400 University Ave., Saint John, NB, E2L 4L2, Canada

3 Department of Emergency Medicine, Dalhousie University, Halifax Infirmary Suite 355-1796 Summer St., Halifax, NS, B3H 3A7, Canada

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Critical Ultrasound Journal 2012, 4:19  doi:10.1186/2036-7902-4-19

Published: 24 August 2012



Ultrasound is being used increasingly to diagnose pathological free fluid accumulation at the bedside. In addition to the detection of peritoneal and pericardial fluid, point-of-care ultrasound allows rapid bedside diagnosis of pleural fluid.


In this short report, we describe the sonographic observation of the vertebral or ‘V-line’ to help confirm the presence of pleural fluid in the supine patient. The V-line sign is a result of the fluid acting as an acoustic window to enable visualization of vertebral bodies and posterior thoracic wall, thus confirming the presence of pleural fluid.


The V-line is a useful sonographic sign to aid the diagnosis of pleural free fluid.