A comparative evaluation of scatter correction techniques in high resolution detectors based on PSPMTs and scintillator arrays

SPECT images suffer from low contrast as a result of photons scatter. The standard method for excluding scatter component in pixelized scintillators is the application of an energy window around the central photopeak channel of each crystal cell, but small angle scattered photons still appear in the photopeak window and they are included in the reconstructed images. A number of scatter correction techniques have been proposed in order to estimate the scatter component but they have not yet been applied in pixelized scintillators, where most groups use the standard one-photopeak window for scatter correction. In this work we have assessed three subtraction techniques that use a different approach in order to calculate the scatter component and subtract it from the photopeak image: The dual energy window subtraction technique (DEWST) the convolution subtraction technique (CST) and a deconvolution technique (DT). All these techniques are compared to the standard method