Pleural effusion in a 16-year-old boy, showing fine echoes, extending 2 cm (doted green line) from parietal pleura (down-pointing thin arrows) to the diaphragm (up-pointing thin arrows). An atelectatic compressed lung is visible at the bottom of the picture as a triangular hypoechoic formation (white triangle). Image captured using a 1.0–7.0 MHz curved array transducer.