Hepatic hydatid cyst disease in low- and middle-income countries: Spectrum of imaging findings and complications

Hepatic hydatid cyst disease is a significant public health issue in endemic low-and middle-income countries, and imaging plays a pivotal role in diagnosis, classification, management, and follow-up. In resource-limited settings, ultrasound (US) is often the imaging modality of choice, with computed tomography (CT) and magnetic resonance imaging (MRI) usually reserved for complex or atypical cases. This pictorial review illustrates the characteristic and atypical imaging features of hepatic hydatid cysts across US, CT, and MRI, emphasizing practical imaging approaches applicable in low- and middle-income countries. US features include daughter cysts, hydatid sand, and detached membranes, whereas CT provides a more detailed assessment of cyst morphology, calcifications, and complications. MRI offers superior soft-tissue contrast and improved evaluation of biliary involvement and complex disease. Important complications include exophytic growth, rupture, transdiaphragmatic thoracic involvement, perforation into hollow viscera, peritoneal seeding, biliary communication and abdominal wall invasion. The US based World Health Organization-Informal Working Group on Echinococcosis classification is also illustrated, highlighting its role in guiding treatment and follow-up. A structured, image-based approach using available modalities enables accurate diagnosis and effective management, whereas pictorial recognition of key imaging features facilitates early detection and improved outcomes in resource-limited settings.