We present a new reconstruction algorithm for single-photon emission comput
ed tomography. The algorithm is based on the Novikov explicit inversion for
mula for the attenuated Radon transform with non-uniform attenuation. Our r
econstruction technique can be viewed as a generalization of both the filte
red backprojection algorithm and the Tretiak-Metz algorithm. We test the pe
rformance of the present algorithm in a variety of numerical experiments. O
ur numerical examples show that the algorithm is capable of accurate image
reconstruction even in the case of strongly non-uniform attenuation coeffic
ient, similar to that occurring in a human thorax.