Ultrasonography of hepatic hydatid cysts: new diagnostic signs.

Eighty-five cases of hepatic hydatid cysts were examined by ultrasonography. On the basis of sonographic patterns (as well as clinical symptomatology and surgical, bacteriologic, and pathologic findings), four groups of cysts were identified: uninfected, organizing, suppurative, and degenerated. A specific sign is defined to differentiate hydatid cysts from cystic lesions of other types. Organizing cysts are defined and ways to differentiate them from infected cysts sonographically are discussed. An analysis was made of the echographically detected material between the daughter cysts previously referred to as "matrix." Clues are given to differentiate infected cysts from liver abscesses. A classification correlating the pathology with the life cycle of the parasite in the human body is proposed.