Local complications of hydatid disease involving thoracic cavity: imaging findings

Hydatid disease, a worldwide zoonosis, is caused by the larval stage of the Echinococcus tapeworm. Although it can involve almost every organ of the body, lung involvement follows in frequency the hepatic infestation in adults and is the predominating site in children. Radiologically, hydatidosis usually demonstrates typical findings, but many patients are at risk of developing various complications of hydatid disease with atypical imaging findings and these are rarely described in the literature. In this pictorial review, the imaging features of local complications of hydatid disease involving the thorax including intrapulmonary or pleural rupture, infection of the ruptured cysts, reactions of the adjacent tissues, thoracic wall invasion and iatrogenic involvement of pleura are described. Additionally, imaging characteristics of transdiaphragmatic thoracic involvement of hepatic hydatid disease are presented. To prevent the development of subsequent catastrophic results, all radiologists need to be aware of the atypical imaging appearances of complications of pulmonary hydatid disease.