Ultrasound features of folded lung

The ultrasound features of folded lung (rounded atelectasis) have not been described previously. The US findings of folded lung in fourteen patients and correlation with computed tomography are presented. The principal US findings were a pleurally based 'mass' and thickening of the adjacent pleura and extrapleural fat. A highly echogenic line extending from the pleural surface into the mass was seen in 12 patients (86%). We believe this finding corresponds to the scarred invaginated pleura as demonstrated in pathological studies of this condition.