The influence of filters on the SPECT image of Carlson phantom

Abstract

Filter backprojection is an important method of im-age reconstruction technique in clinical nuclear medi-cine imaging. Because of noisy images due to less available photon statistics and different factors asso-ciated with imaging system in nuclear medicine to-mography, using optimal filter to suppress the noise with keeping the proper signal is one of the significant steps in image reconstruction strategy for clinical use. In this paper, we present the effect of implementation of different filters on the hot region of Carlson phan-tom SPECT image in reconstruction process. By de-fining some criteria such as image smoothness and contrast, estimation of spatial resolution and location of hot cylindrical sources and their detectability the best filter with specified parameter have been deter-mined and the results have been interpreted. Results show that the perceived image quality of hot region and also their detectability has been improved when Shepp-Logan and Ram-Lak filters with cut-off fre-quency of 0.4 has been used.