The invention relates to a phantom device for reproducing the fluid perfusion in a body, said device comprising a phantom organ that may be introduced into a scanner, said phantom organ comprising a housing in which are defined a plurality of fluid channels, suitably of differing cross-sectional areas; a feed tube arranged to supply liquid to a first end of all of said channels and means for collecting liquid from the other end of the channels. Alternatively or additionally, the device may comprise an element comprising a phantom heart through which fluid can flow, wherein the phantom heart comprises a first chamber representing a right atrium which is arranged to receive fluid from a fluid supply, a second chamber representing a right ventricle which receives fluid leaving said first chamber, a third chamber representing a left atrium which receives fluid leaving the second chamber and a fourth chamber representing left ventricle which receives fluid leaving the third chamber; and wherein a phantom thoracic system is interposed between the second chamber and the third chamber.Uses of the device in quality control, validation or calibration of monitoring devices such as magnetic resonance (MR) or computerized tomography (CT) scanners, in teaching or training of machine operatives or for research purposes including for research into scanners, scanning techniques or reagents such as contrast agents used in such processes, form further aspects of the invention.