Abdominal hydatid disease: role of imaging in diagnosis, complications, and management

Hydatid disease is a relatively common parasitic infection. Incidence can reach more than 50 per 100,000 person-years in endemic areas. It can affect all organs but favors the liver and lungs. Presentation is often asymptomatic. Imaging plays a crucial role in diagnosis in conjunction with serology. Primary evaluation is usually by ultrasound, often followed by CT or MRI, to understand disease extent, including lesion size, internal architecture, multiplicity, location, and adjacent structure involvement. CT better detects lesion calcifications. MRI is advantageous for certain complications such as biliary communication. Cystic lesions with membranes or daughter cysts are highly indicative of hydatid disease. In comparison, diagnosis during the inactive stage can pose challenges at imaging and often also requires tissue sampling. Due to varying appearances at different developmental stages, hydatid disease can mimic various pathologies ranging from cysts to malignancy. Image-guidance aids management. Treatment is based on cyst type, size and location; with uncomplicated cysts typically amenable to PAIR (puncture, aspiration, injection, and re-aspiration) or modified catheterization technique (MoCAT) using scolicidal agents. In contrast, surgical intervention is required for complicated cysts such as those located in a hepatic subcapsular location, those that exhibit biliary communication, or have ruptured.