Iterative reconstruction methods for nonuniform attenuation distribution in SPECT.

Two iterative methods, a generalization of the Chang method and a projection precorrection, were investigated to determine whether the use of an attenuation map could improve nonuniform attenuation compensation. After a detailed description of the methods, results obtained with simulated and phantom data were compared. This study demonstrates that projection precorrection provides accurate quantification and good image quality as early as the precorrection step, whereas the generalized Chang method requires computation of one more iteration.