Simultaneous transmission/emission imaging for SPECT using energy spectrum fitting

Abstract

Energy information is used to generate emission (/sup 99m/Tc, E/spl gamma/=140 keV) and transmission (/sup 57/Co, E/spl gamma/=122 keV) images from a combined projection data set. These components are separated from each other and from Compton scatter by fitting the spectra at each pixel with a simple model. The method is tested using a cylindrical phantom containing inserts with differing attenuation. Emission and transmission position and energy (xyE) data were acquired in list mode and later summed to simulate simultaneous acquisition. Therefore, the emission and transmission images are known. The quality and quantitative accuracy of the technique are evaluated by comparing images extracted from the combined data set to the true scatter-corrected transmission and emission images, respectively. These results are presented and the potential of this technique for accurate attenuation correction in SPECT is discussed. >