TY - JOUR ID - 1936 TI - A New Approach for Scatter Removal and Attenuation Compensation from SPECT/CT Images JO - Iranian Journal of Basic Medical Sciences JA - IJBMS LA - en SN - 2008-3866 AU - Oloomi, Shabnam AU - Noori Eskandari, Hadi AU - Zakavi, Seyed Rasoul AU - Knoll, Peter AU - Kalantari, Faraz AU - Hajizadeh Saffar, Mohsen AD - Department of Medical Physics, Mashhad University of Medical Science, Mashhad, Iran AD - Department of Applied Mathematics, School of Mathematical Sciences, Ferdowsi University of Mashhad, Mashhad, Iran AD - Nuclear Medicine Research Center, Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran AD - Department of Nuclear Medicine Wilhelminenspital Vienna, Austria AD - Research Center for Nuclear Medicine, Tehran University of Medical Sciences, Tehran, Iran Y1 - 2013 PY - 2013 VL - 16 IS - 11 SP - 1181 EP - 1189 KW - Attenuation correction MLEM Scatter correction SPECT DO - 10.22038/ijbms.2013.1936 N2 -   Objective(s): In SPECT, the sinogram contains scatter and lack of attenuated counts that degrade the reconstructed image quality and quantity. Many techniques for attenuation and scatter correction have been proposed. An acceptable method of correction is to incorporate effects into an iterative statistical reconstruction. Here, we propose new Maximum Likelihood Expectation Maximization (MLEM) formula to correct scattering and attenuating photons during reconstruction.   Materials and Methods: In this work, scatters are estimated through Klein-Nishina formula in all iterations and CT images are used for accurate attenuation correction. Reconstructed images resulted from different MLEM reconstruction formula have been compared considering profile agreement, contrast, mean square error, signal-to-noise ratio, contrast-to-noise ratio and computational time. Results: The proposed formula has a good profile agreement, increased contrast, signal-to-noise (SNR) & contrast-to-noise ratio (CNR), computational time and decreased mean square error (MSE) compared with uncorrected images and/or images from conventional formula. Conclusion: In conclusion, by applying the proposed formula we were able to correct attenuation and scatter via MLEM and improve the image quality, which is a necessary step for both qualitative and quantitative SPECT images. UR - https://ijbms.mums.ac.ir/article_1936.html L1 - https://ijbms.mums.ac.ir/article_1936_163bd50f33052275b849fecd75daaaf7.pdf ER -