<div class="__aliyun_email_body_block"><div  style="clear:both;"><span  style="font-family:Arial,sans-serif;font-size:15.0px;text-align:justify;">Dear CASToR Users and Developers,</span><br ></div><div  style="clear:both;"><div  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor" id="sign_card2" style="margin:.0px;padding:.0px;color:#000000;font-size:16.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:left;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-thickness:initial;text-decoration-style:initial;text-decoration-color:initial;"><div  style="margin:.0px;padding:.0px;border:.0px;outline:.0px;color:#000000;font-family:Tahoma,Arial;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;text-decoration-thickness:initial;text-decoration-style:initial;text-decoration-color:initial;clear:both;">We design a small-caliber PET system that has serious DOI parallactic error. With the help of CASToR, right now I reconstructed 7 point sources placed in different offsets which showed in the attachment. Obviously, the point on the far right deteriorated seriously. Since I used 0.79mm(crystal size) FWHM isotropic Gaussian kernel function as PSF in castor-recon command, detector responses caused by different incident angles are not considered. So I need to design a dynamic PSF with single-photon incidence response instead of Static symmetric Gaussian distribution as the PSF to generate the system matrix on the fly. </div><div  style="margin:.0px;padding:.0px;border:.0px;outline:.0px;color:#000000;font-family:Tahoma,Arial;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;text-decoration-thickness:initial;text-decoration-style:initial;text-decoration-color:initial;clear:both;">Does anyone know how I can make this? Because I just find out how to change the standard normal distribution into another static distribution function, fail to relate <span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor" style="margin:.0px;padding:.0px;border:.0px;outline:.0px;color:#000000;font-family:Tahoma,Arial;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-thickness:initial;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;">the current LOR to </span>the distribution function. Any reply will be appreciated.</div><div  style="margin:.0px;padding:.0px;border:.0px;outline:.0px;color:#000000;font-family:Tahoma,Arial;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;text-decoration-thickness:initial;text-decoration-style:initial;text-decoration-color:initial;clear:both;"><span  class=" __aliyun_node_has_color" style="margin:.0px;padding:.0px;border:.0px;outline:.0px;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"><br  class=" __aliyun_node_has_color" style="outline:none medium;color:#000000;font-family:Tahoma,Arial;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;orphans:2;text-align:start;text-indent:.0px;text-transform:none;white-space:normal;widows:2;word-spacing:.0px;"><span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor" style="margin:.0px;padding:.0px;border:.0px;outline:.0px;color:#000000;font-family:Tahoma,Arial;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-thickness:initial;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;">Thank you a lot,</span></span></div></div></div><div  style="clear:both;"><div  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor" id="sign_card2" style="margin:.0px;padding:.0px;color:#000000;font-size:16.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:left;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-thickness:initial;text-decoration-style:initial;text-decoration-color:initial;"><div  style="margin:.0px;padding:.0px;border:.0px;outline:.0px;color:#000000;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;text-decoration-thickness:initial;text-decoration-style:initial;text-decoration-color:initial;clear:both;">Zhao Xin</div></div></div></di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