Modified convolution-subtraction scattering correction technique for 3D PET

A modified convolution-subtraction (CS) scatter correction technique in 3D PET imaging has been proposed and evaluated. It can compensate for the shortcomings with the conventional CS techniques, which are commonly used in 2D PET data. The shortcomings include requiring the position-dependent scatter-kernel calibration, the non-standard convolution and long processing time. The modified CS technique assumes that the position-dependent scatter response function (SRF) can be modeled by a product of an average SRF, an adjustable parameter and a relative scatter fraction function. The relative scatter fraction function is a function of source position. The technique was applied to both simulated and measured data. The preliminary results indicate that the modified CS scattering correction technique is practical and robust to the sizes of objects. It provides more accurate scatter estimates than the conventional CS techniques, especially for highly nonuniform distributed sources.