Abstract: Tomographic or sectional X-ray images (46) of a subject (32) are obtained rapidly by a method and apparatus that do not inherently require motion of the X-ray source (12) and detectors (13) or motion of the subject in order to generate the tomographic image data. In the source, a charged particle beam (17) is directed to a broad target plate (18) and raster scanned to produce a moving X-ray origin point (19). X-ray count values are obtained at a plurality of spaced apart detection points (D1, D2, D3, D4, D5, D6, D7) situated at the opposite side of the subject from the source. Successive count values from a first detection point are combined with successive count values from at least one other detection point that originated at a later time in the course of the raster scan to provide a sequence of composite data values.