Alveolar hydatid disease of the liver: Brief review and spectrum of adjacent organ invasion MK Demir, 1 G Kilicog ˘ lu 2 and O Akinci 2 1 Department of Radiology, Trakya University School of Medicine, Edirne, and 2 Department of Radiology, Haydarpasa Numune Education and Research Hospital, Istanbul, Turkey SUMMARY The purpose of this study is to show the spectrum of adjacent organ invasion and to make a brief review of hepatic alveolar hydatid disease (AHD), using CT and MR imaging. We retrospectively reviewed CT and MR images of three patients with various adjacent organ invasions surgically and histologically proven to be AHD. Local invasion to right kidney and adrenal, right hemidiaphragm and lung were detected in one patient, right adrenal in another patient and gall bladder, duodenum, gastric wall and pancreas invasion in the other. AHD may rarely extend to the gall bladder, stomach, duodenum, pancreas, right adrenal and kidney, diaphragm, pleura and lung. The extension of the disease outside the liver is usually encountered in patients with large, peripherally located masses in the advanced stage of the disease. Key words: alveolar hydatid; CT-spiral; cysts; infection; liver; MR-imaging. INTRODUCTION Alveolar hydatid disease (AHD) of the liver is a rare parasitic infection of humans caused by the larvae of echinococcus mul- tilocularis infestation in the liver. 1,2 The clinical course of the disease varies from an asymptomatic liver lesion to an invasive mass. In the latter condition, the disease resembles that of a slowly developing tumour. Invasion of biliary and vascular structures of liver may result in biliary obstruction, portal hyper- tension, oesophageal variceal bleeding or Budd–Chiari syn- drome. Extension outside the liver may rarely occur. 3 Surgical treatment is the main curative treatment for the extrahepatic disease and usually requires preoperative definition of the extension. Computed tomography and MR appearances of adjacent organ invasion in three patients with AHD are described. MATERIALS AND METHOD Patients Three patients (mean age 52 years; range 33–71 years) referred to our institution over a 3-year period and diagnosed with AHD were retrospectively reviewed. All patients, one male and two females, were from eastern parts of Turkey where the disease is endemic. Physical examination finding, laboratory tests and histopathological examinations were available for all three patients. One patient was evaluated with CT imaging only, whereas the others were studied with both CT and MR imaging. Computed tomography and magnetic resonance imaging technique Abdominal CT scans of the patients were performed on a single-slice spiral CT scanner (Pronto; Hitachi, Tokyo, Japan). Unenhanced and contrast-enhanced images were obtained using 8-mm collimation with a table speed of 8 mm/s (pitch = 1), extending from the diaphragm to the level of the iliac crest. Contrast-enhanced images were obtained 50–70 s after i.v. administration of 120 mL of ionic contrast material (meglumine ioxitalamate, 300 mg I/mL (Telebrix 30), Guerbet) using a power injector at a rate of 3 mL/s. Magnetic resonance imaging was performed with 1.5-T scanners (Gyroscan Intera and Gyroscan ACS-NT; Philips Medical Systems, Best, The Netherlands) using a surface phased-array coil (Synergy body array coil; Philips Medical MK Demir MD; G Kilicog ˘ lu MD; O Akinci MD. Correspondence: Professor Mustafa Kemal Demir, 11 Kisim, Yasemin Apt, D blok, Daire 35 Atako ¨ y, Istanbul 34158, Turkey. Email: demirkemal@superonline.com Submitted 6 March 2006; accepted 24 July 2006. doi: 10.1111/j.1440-1673.2007.01748.x Radiology Original Article Australasian Radiology (2007) 51, 346–350 ª 2007 The Authors Journal compilation ª 2007 The Royal Australian and New Zealand College of Radiologists