Chapter 5 - Emission-Transmission Realignment Using a Simultaneous Emission-Transmission Postinjection Scan

Abstract

This chapter demonstrates that the emission part of the postinjection simultaneous emission and transmission scan (PITsim), is a reliable reference image when aligning brain FDG images and for a large range of neuroreceptor studies. The method presented in the chapter is based on a method for alignment of transmission and emission scan data, but it eliminates the requirement of no motion between the transmission scan and the first scan of the emission sequence. This method can be used even in those cases where the patient needs to exit the scanner between successive scanning sequences or when the patient moves between transmission and emission scans. Phantom studies have indicated that the most reliable quantitative results are obtained when a transmission scan is acquired in the same position as the emission scan. When this is not possible, a registration between transmission and emission scans improves the qualitative and quantitative image degradation because of the spatial mismatch between emission and transmission scans.