Search for: [Abstract = "A cylindrical phantom filled with a water solution of 131\"I\" containing a region of \?cold\? spheres as well as a uniform solution \(without any spheres\) was used to perform algorithm evaluation. The reconstructed images obtained by using four different of methods system matrix computation were compared with those achieved using reconstruction software implemented in the gamma camera. The contrast of the spheres and uniformity were compared for each reconstruction result and also with the ranges of those values formulated by the AAPM \(American Association of Physicists in Medicine\)."]