Ultrasound of the pre‐hepatic portal vein (right side of image) entering the liver. Hepatic emphysema is seen as hyperechoic foci within the hepatic parenchyma (large arrow) and associated reverberation artifact (not well‐visualized in the image). Gas bubbles within the lumen of the portal vein are seen as strongly echogenic particles (dashed arrow). Gas shadowing (small arrow) with associated comettail artifact represents bubbles within the non‐dependent portion of the portal vein