Radiological manifestations of hydatid disease and its complications

Hydatid disease (HD) is endemic in many parts of the world. HD can affect virtually any organ system in body and should be kept as differential diagnosis of cystic lesion. HD is mostly asymptomatic; however, it demonstrates a variety of characteristic imaging findings depending on the site of involvement, stage of growth, mass effect, complications, or hematogenous spread, which helps in diagnosis. Radiography, ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI) are commonly used imaging modalities. Radiography is helpful in chest and for demonstrating calcification. USG demonstrates characteristic findings such as cystic nature, daughter vesicles, membranes, septa, and hydatid sand. CT and MRI are modalities of choice for number, size, anatomic location, identification of local complications, and systemic spread. CT is, especially helpful for osseous involvement, and MRI is better for biliary and neurological involvement. Knowledge of these imaging findings helps in early diagnosis and timely initiation of appropriate therapy.