US manifestations of liver abscesses: An experimental study

Staphylococcus aureus and Bacillus fragilis with Escherichia coli were inoculated into the livers, gallbladders, and portal veins of 3.0-3.5-kg male rabbits, respectively, to induce liver abscesses and for comparison of their US and pathologic findings. No morphologic difference was noted between S. aureus and anaerobic infections. Small abscesses were generally echogenic. Histologically, these abscesses consisted of the abscess and coagulation and granulation tissues. The same structure with an irregular margin and a partial colliquative necrosis produced a bull's-eye appearance. Central lower echoes of a so-called established abscess was caused by colliquative necrosis, with echogenic surroundings from abscess material and granulation tissue