1. A method for producing a radiological phantom comprising obtaining a radiograph representing a radiographic image of a particular view of a body part to be simulated in a defined radiographic environment, densitometrically scanning the radiograph with a densitometer, digitizing and sampling the densitometer output at a sampling rate sufficient to produce data defining a densitometric image of the body part having a spatial resolution sufficient that the phantom can substantially reproduce the original radiograph when imaged in the same environment, obtaining the phantom, such as to relate radiographic density to material thickness in the radiographic environment used for obtaining the radiograph and over a range of densities comprising the density range of the radiograph, using the calibration data to translate the densitometric data defining the image into thickness data, and using said thickness data to form from the same material as the sample a three dimensional representation of the thickness data configured to overlay a radiographic image plane and to produce in said defined radiographic environment an image similar to that which would have been produced by said particular view of the original body part in that environment.