title: Alveolar echinococcosis: spectrum of findings at cross-sectional imaging.
abstract: Alveolar echinococcosis is a rare parasitic disease caused by the fox tapeworm Echinococcus multilocularis, which is endemic in many parts of the world. Without timely diagnosis and therapy, the prognosis is dismal, with death the eventual outcome in most cases. Diagnosis is usually based on findings at radiologic imaging and in serologic analyses. Because echinococcal lesions can occur almost anywhere in the body, familiarity with the spectrum of cross-sectional imaging appearances is advantageous. Echinococcal lesions may produce widely varied imaging appearances depending on the parasite's growth stage, the tissues or organs affected, and the presence of associated complications. Although the liver is the initial site of mass infestation by E multilocularis, the parasite may disseminate from there to other organs and tissues, such as the lung, heart, brain, bones, and ligaments. In severe infestations, the walls of the bile ducts and blood vessels may be invaded. Disseminated parasitic lesions in unusual locations with atypical imaging appearances may make it difficult to narrow the differential diagnosis. Ultrasonography, computed tomography (CT), magnetic resonance (MR) imaging with standard and diffusion-weighted sequences, and MR cholangiopancreatography all provide useful information and play complementary roles in detecting and characterizing echinococcal lesions. Cross-sectional imaging is crucial for differentiating echinococcosis from malignant processes: CT is most useful for depicting the peripheral calcifications surrounding established echinococcal cysts, and MR imaging is most helpful for identifying echinococcosis of the central nervous system.
authors.affiliation: Department of Radiology, Atatürk University, School of Medicine, 200 Evler Mah. 14. Sok No 5, Dadaskent, Erzurum 25090, Turkey. akkanrad@hotmail.com
authors.forename: Mecit
authors.initials: M
authors.lastname: Kantarci
authors.forename: Ummugulsum
authors.initials: U
authors.lastname: Bayraktutan
authors.forename: Nevzat
authors.initials: N
authors.lastname: Karabulut
authors.forename: Bulent
authors.initials: B
authors.lastname: Aydinli
authors.forename: Hayri
authors.initials: H
authors.lastname: Ogul
authors.forename: Ihsan
authors.initials: I
authors.lastname: Yuce
authors.forename: Muhammet
authors.initials: M
authors.lastname: Calik
authors.forename: Suat
authors.initials: S
authors.lastname: Eren
authors.forename: Sabri Selcuk
authors.initials: SS
authors.lastname: Atamanalp
authors.forename: Aytekin
authors.initials: A
authors.lastname: Oto
mesh_terms: D019412:Anatomy, Cross-Sectional / Q000379:methods*; D003937:Diagnosis, Differential; D004443:Echinococcosis; D004444:Echinococcosis, Hepatic / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*