Figure 1. 19-year-old male with gas in portal and systemic venous system. (a) Grey scale ultrasound reveals gas bubbles in the right main portal vein demonstrating the string of pearls sign. (b) Ultrasound images show the hyperechogenic appearance of the liver parenchyma due to gas bubbles in the peripheral venous structures (short arrows). Also note air bubbles in the lumen of inferior vena cava and hepatic veins.