Computed tomography of pulmonary hydatid disease.

The CT findings in 20 patients with pulmonary hydatid disease were reviewed. Sixty-four intrapulmonary cysts were imaged, 22% of which were ruptured or complicated. Simple hydatid cysts and water-density lung cysts of other etiology may have a similar CT appearance; however, the demonstration of the cystic nature of a lung lesion in endemic areas makes hydatid disease the primary consideration. Pathognomonic features in ruptured or complicated hydatid cysts that can be visualized better by CT than by conventional radiography include detached or collapsed endocyst membrane(s), collapsed daughter cyst membranes, and intact daughter cysts.