Intramural hydatid cysts of pulmonary arteries: CT and MR findings

Involvement of the pulmonary artery by echinococcosis usually occurs due to pulmonary embolization after rupture of the cyst in the right ventricle or, rarely, by dissemenation from a hepatic focus. This paper presents an adult patient with intramural hydatid cysts of the pulmonary arteries, which apparently grew slowly toward the lumina resulting in complete luminal occlusion, enabling sufficient time for development of sufficient perfusion from the bronchial arteries. The condition apparently resulted from embryos of the parasite, which entered the "vasa vasorum" of the pulmonary arteries, a previously unreported mechanism. © 1995 Springer-Verlag.