Hydatid Disease from Head to Toe

http://radiographics.rsna.org/content/23/2/475.full

Pinar Polat, MD ; Mecit Kantarci, MD ; Fatih Alper, MD ; Selami Suma, MD ; Melike Bedel Koruyucu, MD ; Adnan Okur, MD

1 From the Department of Radiology, Faculty of Medicine, Atatürk University, Erzurum, Turkey. Received April 15, 2002; revision requested June 11 and received August 16; accepted August 19. Address correspondence to P.P., Istasyon mah, Kombina cad, Armagan Apt 4/7, Erzurum, Turkey.

Hydatid disease (HD) is a unique parasitic disease that is endemic in many parts of the world. HD can occur almost anywhere in the body and demonstrates a variety of imaging features that vary according to growth stage, associated complications, and affected tissue. Radiologic findings range from purely cystic lesions to a completely solid appearance. Calcification is more common in HD of the liver, spleen, and kidney. HD can become quite large in compressible organs. Hydatid cysts (HCs) can be solitary or multiple. Chest radiography, ultrasonography (US), computed tomography (CT), magnetic resonance (MR) imaging, and even urography can depict HCs. The imaging method used depends on the involved organ and the growth stage of the cyst. US most clearly demonstrates the hydatid sands in purely cystic lesions, as well as floating membranes, daughter cysts, and vesicles. CT is best for detecting calcification and revealing the internal cystic structure posterior to calcification. MR imaging is especially helpful in detecting HCs of the central nervous system. Radiologic and serologic findings can generally help establish the diagnosis of HD, but an HC in an unusual location with atypical imaging findings may complicate the differential diagnosis. Nevertheless, familiarity with imaging findings, especially in patients living in endemic regions, is advantageous in this context.