A phantom for use in quality control of tomographic images, the phantom including a cylindrical plate made of a uniform material having a density d1, with two cylinders being inserted in the plate, the cylinders being made out of uniform materials having different densities d2, d3, the density of one of the cylinders being greater than the density d1 of the plate, and the density of the other cylinder being less than the density d1 of the plate, and including a first series of pairs of holes of different diameters drilled in the plate, the axes of the holes of the first series being oriented axially relative to an axis of revolution of the plate, and the holes in a given pair being spaced apart from each other by a distance equal to their diameter.