Appearance of Disease:

This ultrasound image of the right upper quadrant (RUQ) of the abdomen shows an "echodense" gallstone (calculus) impacted in the outlet of the gallbladder. This obstruction to the outflow of bile has resulted in acute inflammation of the gallbladder (cholecystitis), with secondary bacterial infection causing the organ to fill with pus (empyema). Peritoneal fat (omentum) has become adherent to the gallbladder, and is also acutely inflamed.