Method and apparatus for tomography wherein signal profiles derived from an out-fanning beam of penetrating radiation can be reconstructed into signal profiles each corresponding with a beam of parallel incident rays

摘要

A method and apparatus for pre-processing by means of analogue techniques radiological information obtained by exposing a subject at various spaced positions on one side of this subject to an out-fanning, substantially flat beam of penetrating radiation. The resultant ray transmissions on the other side of the subject are recorded on a record medium as continuous and analogue signals located along a collection of recording paths each having a predetermined trajectory and a spatial orientation related to an associated position of exposure. The radiological information thus recorded is then scanned and read-out along another collection of adjacent scanning paths each having a predetermined trajectory which intersects different recording paths and likewise having a spatial orientation related to the associated position of exposure. The information thus read out represents analogue radiological information resulting from a virtual exposure to substantially parallel rays of penetrating radiation, and permits the reconstruction of desired laminal planes of the subject by means of a process involving a single convolution function.