Ultrasonographic Manifestations of Liver Abscesses : An Experimental Study

The livers and portal veins of 3.0-3.5 kg male rabbits were inoculated with S. aureus, and E. coli combined with B. fragilis to induce liver abscesses and relate ultrasonographic images to pathologic findings. There were no morphological differences between those of S. aureus and the anaerobic infections. Small abscesses were generally echogenic, and consisted histologically of polymorphs, coagulation and granulation tissue. These irregularly-margined structures with liquefective necrosis had "bull's-eye" appearances. So-called "established abscesses" with hypoechoic surroundings were also observed, with central liquefective necrosis, polymorphs and granulation tissue peripherally. The peripheral echo-free halos were attributed to coagulation necrosis.