| 摘要 |
PURPOSE:To calculate distribution to plural sampling points at a high speed by calculating previously the values of the respective distribution quantities of plural positions of pixels and storing as a table, and reading the table of projection directions and object pixels of projection. CONSTITUTION:The value of the projection quantity of every finite number of positions is written previously in a distribution memory 5 according to the distribution of the projection quantity of one pixel determined by a projection direction. When a projection direction and a pixel position are specified, the projection position of the center point of the pixel and sampling points at its periphery are calculated by an address calculator 2. A projection value of each position of a pixel in the due projection direction is read out of the distribution memory 5 and added by an adder 6 and the quantity of distribution to respective sampling points is calculated by a distribution calculator 3. The concentration distribution of nuclear species stored in a tomographic image memory 1 is read out and the concentration value regarding this pixel is multiplied by the distribution quantity by multipliers 8 and 9, and the results are stored in a synogram memory 12.
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