Pericardial effusion - water bottle sign

Case contributed by Assoc Prof Frank Gaillard


Shortness of breath.

Patient Data

Age: Adult
Gender: Male

Chest x-ray (mobile).

Front chest x-ray demonstrates marked enlargement of the cardiac outline. This was due to pericardial effusion and is a good example of the water bottle sign. This refers to the shape of the cardiac silhouette on erect frontal chest x-rays in patients who have a very large pericardial effusion. The fluid, often measuring a liter or more, causes the pericardium to sag mimicking an old-fashioned water bottle sitting on a bench. Typically the effusion has accumulated over many weeks (e.g. in patients with malignancy) and the pericardium has gradually stretched.

Case Discussion

It is always worth remembering that although many radiologists will report chest x-rays as "the cardiac outline is enlarged" or even "the heart is enlarged", this is not always the case. Epicardial, anterior mediastinal or intrapericardial conditions can all look very similar. 

In this case the patient had a large pericardial effusion, confirmed on echocardiography. 

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Case information

rID: 7142
Published: 8th Sep 2009
Last edited: 18th Jan 2020
System: Chest, Cardiac
Inclusion in quiz mode: Included

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