Fertility assessment of hydatid cyst by proton MR spectroscopy

Background. Hydatid cysts, the larvae of the parasite Echinococcus granulosus, may lodge in any organ of intermediate hosts, namely, man and sheep. Complete cyst removal is the treatment of choice; however, spillage of fertile cysts during surgery leads to disease recurrence that may be prevented by preoperative detection of the fertility status of the cyst. With this perspective, ex vivo proton (H-1) MR spectroscopy of hydatid fluid of human and sheep origin was performed to differentiate fertile from sterile cysts on the basis of their metabolite pattern. Patients and materials. Cysts of sheep and human origin were used as source of hydatid fluid. A fraction of this fluid was tested for cyst fertility and the rest was used for ex vivo H-1 spectroscopy. Histopathology of the cyst wall was done as a gold standard for this study. Results. Of 10 sheep samples, 7 were fertile and 3 were sterile, while among 6 human samples, 5 were fertile and 1 was sterile. Spectroscopic and histopathological results corroborated each other. The fluid from microbiologically proven fertile cysts contained malate and fumarate along with other resonances and the histopathology of the fertile cyst wall demonstrated germinal lining and protoscoleces. Conclusions. The ex vivo spectroscopic differentiation of fertile and sterile cysts may be a stepping-stone for their in vivo separation in future and thus help in framing strategies for percutaneous/surgical management. (C) 2002 Elsevier Science (USA).