Two-dimensional ultrasonographic findings of atelectatic lung segments.

Thirteen cases with pulmonary atelectasis were examined by two-dimensional sonography in our clinics between October 1990 and April 1993. Patients' ages ranged from 2 to 16 years. Five patients revealed atelectasis with pleural effusion and eight patients had only atelectasis. Two-dimensional sonography showed a solid mass indistinguishable from lung parenchyma in patients with atelectatic lung segment without pleural effusion while atelectatic segment was readily identified in those with pleural effusion. We conclude that sonography is a useful and non-invasive technique in differentiating cardiac from extracardiac masses, because atelectatic lung segment with moderate to large pleural effusion may mimic intrapericardial masses.