SPECT reconstruction by simulated annealing.

The technique of simulated annealing has been introduced for reconstruction in single photon emission computed tomography (SPECT) of data from rotating gamma camera systems. This is a much used technique in fields other than medical imaging but has only been used for one previous medical imaging application by Barrett et al (1983). It is shown that for noiseless data, the method can give perfect quantitative results, even when photon attenuation is included in the problem. This is true whatever the object distribution. With noisy data, mean level quantitation is still achievable although image mottle is worse. This paper describes simulated annealing in the language of SPECT, paying particular attention to the computational tricks which are central to a practicable implementation. The results of many computer simulations are presented to show the potential power of the method. A short comparison with other reconstruction techniques is made.