The antrum is round and distended with thin walls. The content appears anechoic or hypoechoic. The size of the antrum is proportional to the gastric volume. The antrum will appear larger in the right lateral decubitus position compared to the supine position.
Reproduced with permission from: Van de Putte P, Perlas A. Image Acquisition: Scanning Technique. Gastric Ultrasound. Copyright © 2018. Available at:
https://gastricultrasound.org (Accessed on June 29, 2018).