Alveolar echinococcosis in a 34-year-old man. (a) CT plain scan shows a cyst-solid mixed hepatic mass involving both lobes of liver with irregular margin and necrosis areas of low density in the center. (b) Post-contrast phase shows a non-enhancing, hypo-attenuating lesion. (c) Blood flow map, and (d) blood volume map, at CT perfusion, show the micro-circulation in the marginal area of AE.