Figure 1c: Images of anthropomorphic CT phantom used to study multi–detector row CT scanner attenuation values. (a) Photograph (transverse view) shows phantom with customized 140-HU renal insert. K = Kidney. (b) Diagram of renal insert (side view) shows stacked 7-, 10-, and 15-mm-diameter cylindric cysts measuring 0 and 50 HU. (c) Transverse multi–detector row CT scan shows internal phantom components that simulate normal anatomic structures and both 0-HU (white arrow) and 50-HU (black arrow) cylindric cysts within left kidney.