In this radiology lecture, we discuss the ultrasound and CT appearance of amebic liver abscess. Key points include: * Entamoeba histolytica infection. * Endemic in Africa, Southeast Asia, and Central & South America. * More common in males. * Presents as right upper quadrant pain, fever and hepatomegaly. * Both amebic and pyogenic (bacterial) abscesses can have a layered wall with the “double target” or “double rim” sign. * Amebic more likely to be unilocular (septations present in 30%) without “cluster” sign typical of multiloculated pyogenic abscess. * Amebic more likely solitary, pyogenic more likely multiple. * Can be treated medically (metronidazole), but if diagnosis uncertain, if there is failed response to medical therapy, or if large abscess at risk for rupture = aspiration. Bächler P, Baladron MJ, Menias C, et al. Multimodality Imaging of Liver Infections: Differential Diagnosis and Potential Pitfalls. RadioGraphics 2016 36:4, 1001-1023. Click the YouTube Community tab or follow on social media for bonus teaching material posted throughout the week! Instagram: https://www.instagram.com/radiologistHQ/ Facebook: https://www.facebook.com/radiologistHeadQuarters/ Twitter: https://twitter.com/radiologistHQ