The invention provides a perfusion chamber for use in a phantom comprising a waterproof housing containing a porous material, the porous material defining fluid paths between pores and tubular channels within the porous material. The invention further provides a reservoir for use in a phantom, a pump mechanism for use within the bore of an MRI scanner, a phantom for use in an MRI scanner, and a method for calibrating a scanning device. The invention also provides an apparatus for validating images of a phantom, the apparatus comprising: one or more sensors for coupling to a phantom to be imaged, the sensors being configured to measure parameters associated with the operating state of the phantom; a control/logging system configured to: collect sensor data during imaging of the phantom by the imaging system and pass this as input to a computer model; compare the image data with reference image data produced using the computer model; and return a pass score in dependence on the comparison. The invention also provides a system for verifying images of a phantom and a method for verifying images of a phantom.