Process for the reconstruction of three-dimensional images of an object by measurements using a conical radiation and a bidimensional detector array

Claim 1

Process for the reconstruction of three-dimensional images of an object (3) defined by values assumed by a function (f) on points (M) of the object, the function being a property of a conical radiation having a focal point (F) passing through the object (3), in which the function is calculated by means of sums of the function on parametrized planes (P) passing through at least one point of the object and defined in an object mark (O, i, j, k) having an origin (O), the process having at least one series of measurements carried out in different positions of the focal point about the object, each sum of the function on said parametrized planes in the object mark being calculated from at least one of the measurements, each of the measurements being carried out with a bidimensional array (4) of detectors (6) of the radiation oriented towards the focal point and which is displaced on a trajectory about the object perpendicular to a rotation axis, the focal point being displaced at the same time as the detector array so as to be projected orthogonally onto a fixed point (Gd) of the detector array, an inversion algorithm being used for finding again the value assumed by the function on the points of the object with the aid of sums of the function on the parametrized planes, the algorithm having stages of determining at least one position of the focal point belonging to each of the said associated parametrized planes, characterized in that the focal axis, defined as the orthogonal projection line (FGd) of the focal point on the array passes to one side of the origin (O) and in that the determination stages involve calculations using the parameters (Δ, φ, ξ) expressing the variation between the focal axis and the origin and the inclination between the focal axis and the rotation axis.