Reconstruction of the Fresnel-coded gamma camera images by digital computer.

An algorithm for the digital reconstruction of the Fresnel-coded gamma camera image consists of the spatial Fourier transform of the hologram after applying a quadratic phase shift. Background subtraction is implemented by use of positive and negative zone plates. Tomographic planes are reconstructed in 27 sec from a single zone-plate shadow image by successively varying a parameter in the reconstruction algorithm on a small computer system.