Fig. 1.

Example of a gastric ultrasonographic image. The antrum was located superficially between the left lobe of the liver anteriorly and the pancreas posteriorly in a sagittal or parasagittal scanning plane in the epigastrium. Important vascular landmarks including the inferior vena cava (IVC) and the superior mesenteric vein was marked the standard scanning plane of the antrum. Antralcross-sectional area (CSA) can be measured by using two perpendicular diameters (antero-posterior diameter and craniocaudal diameter) and the formula of the area of an ellipse