Sonographic demonstration of air-fluid levels in abdominal abscesses

Abdominal sonograms were obtained for three patients who had clinically suspected abscesses. There were abnormal fluid collections that, when viewed from a posterior position, demonstrated a horizontal line representing an air-fluid level. Abdominal abscesses containing air were confirmed by both horizontal beam radiography and surgery. Since ultrasound examination is frequently performed before radiography in patients thought to have abscesses, it is important to look for and recognize the sonographic appearance of an air-fluid level.