Axial tomography

In an apparatus for producing an axial tomographic image of an object, with a detector for receiving radiation along a plurality of sets of paths, with said sets of paths overlapping each other, providing a plurality of sets of radiation detector output signals, the improvement including in combination:

• first means for storing said detector output signals in analog form at a surface with signals of one set overlying signals of another set whereby the signals resulting from radiation through a zone of the object are summed at a corresponding zone at said surface producing a first stored signal;
• first means for reading said first stored signal, including means for scanning across said surface and means for producing second signals, with a second signal for a scan point being a function of the magnitude of the first stored signal at the scan point and varying substantially inversely proportional to distance from the scan point;
• second means for storing said second signals producing second stored signals;
• and
• second means for reading said second stored signals at each of a plurality of points of said second storage means and including means for producing a video signal for each point, with a video signal being substantially the Laplacian of the second stored signal for the point, and with the video signal corresponding to the desired image.