Abstract: A process and appparatus for obtaining three-dimensional images of an object with an application of the process and the device to the tomography of an organ. The device includes a detector or mobile rays which rotates about the object and mechanisms which provide references for the angular position of the detector with respect to the reference plane. The detector contains detection areas which receive the radiation and are identified by their number and emit signals, the amplitude of which depends on the intensity of the received rays. Also included in the device is an iterative processing machine which operates by convergent processing of the signal amplitude values with the processing mechanism being connecting to visualization devices in order to display the images of the object in various cross-section planes after each iteration.