The subpulmonic pleural effusion: sonographic aspects

A pleural effusion might be missed on an ultrasound examination if it is done only with the patient in a supine position. Ultrasound should be done sitting or standing to rule out pleural effusions. A patient is presented who had a subpulmonic pleural effusion on a chest radiography. The effusion was not visualized on supine sonography but was clearly visualized with the patient upright.