Emission based attenuation correction of PET images of the thorax

Reports investigations on a method for obtaining an emission based attenuation correction of PET studies specifically in the thorax. The following components of the method were evaluated: body contour determination, lung contour estimation using a lung atlas, refinement of the lung contour using the consistency conditions and additional refinement of the attenuation map using a coupled iterative algorithm to alternately update both the emission and transmission distributions. Body contours could be determined with a high degree of accuracy, but the lung contours could not. The consistency conditions (up to and including the second order) did not provide a substantial improvement to the initial lung contour estimate. The coupled reconstruction algorithm also did not converge to an acceptable solution. It is concluded that these techniques are insufficient for generating an attenuation correction based solely on emission data