Sonographic image of the gastric antrum in the epigastric area obtained in a sagittal plane using a curved-array low-frequency probe. The arrows signal the gastric antrum which appears empty, small, with no discernible content. Note a hypoechoic layer within the gastric wall that corresponds to the muscularis propriae. Ao = aorta; L = liver; P = pancreas; S = splenic vein.