Attenuation correction in cardiac SPECT using consistency conditions

In this work the approach for obtaining the attenuation maps for cardiac SPECT was the estimation directly from the emission data, without transmission imaging, based on consistency conditions of the attenuated Radon transform. Several counting rates and attenuation coefficients on the corrected images were studied, using the MCAT phantom and SimSET package. Given an initial estimate of the attenuation map, the use of consistency conditions always resulted in a same form, for any values initials of the group of parameters. In spite of the fact that the error falls with the increasing counting rate, higher counts are not able to determine the best attenuation coefficient. The results shows that consistency conditions can be useful for attenuation correction, but the scattering correction is the most important factor in the quantitative reconstruction in cardiac SPECT.