CROSS-PLANE SCATTERING CORRECTION - POINT-SOURCE DECONVOLUTION IN PET

Most previous scattering correction techniques for PET are based on assumptions made for a single transaxial plane and are independent of axial variations. These techniques will incorrectly estimate the scattering fraction for volumetric PET imaging systems since they do not take the cross-plane scattering into account. We propose a new point source scattering deconvolution method (2-D). The cross-plane scattering is incorporated into the algorithm by modelling a scattering point source function. In the model, the scattering dependence both on axial and transaxial directions is reflected in the exponential fitting parameters and these parameters are directly estimated from a limited number of measured point response functions. Our results comparing the standard in-plane line source deconvolution to our cross-plane point source deconvolution show that for a small source, the former technique overestimates the scatter fraction in the plane of the source and underestimates the scatter fraction in adjacent planes. In addition, we also propose a simple approximation technique for deconvolution.