Pleural effusion - supine

Case contributed by Paul Heyworth
Diagnosis certain


Severe pancreatitis. Intubated and ventilated in ICU. X-ray requested for: 1) assessment of NGT position 2) changes in air entry on the right side.

Patient Data

Age: 55 years
Gender: Male

Supine position


NGT, ETT, right sided PICC and left CVL are in appropriate position. Right CVL tip projected at the level of the right proximal clavicle. 

Obscuration of the right heart border is favored to be due to rotation. Lungs are clear. Veiling opacity of the left hemithorax is in keeping with a left sided pleural effusion. 


Moderate left sided pleural effusion with mild left lower lobe atelectasis confirmed on CT. Postsurgical changes within the abdomen and large peripancreatic collection.

Case Discussion

On supine projections, pleural effusions produce a "veiling opacity", which is due to pleural fluid preferentially collecting posteroinferiorly in the pleural space. On erect films, pleural effusions are most commonly a basal opacity with a meniscus. 

Other causes of a veiling opacity include left upper lobe collapse.

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