Introduction:  In  this  study,  we  utilized  the  MCNP4C  Monte  Carlo  code  to  quantitatively  evaluate  the  influence of crystal size and material on intercrystal scatter and parallax effects.   Materials and Methods:  For each of the 5 selected crystals (BGO, LSO, LYSO, LuAP, GSO), transport of  511  keV  photons  originating  from  a  point  source  and  incident  on  the  central  cry...

Introduction: The position estimation in gamma detection system will have constant misplacements which can be corrected in the calibration procedure. In the pixelated crystal uniformly irradiation of detector will produce irregular shape due to position estimation errors. This image is called flood field image and is used to calibrate the position estimation. In this work we pr...

objectives this study aimed to assess the effect of object position in the field of view (fov) of cbct on detection of vrfs in teeth with intra-canal posts. materials and methods the crowns of 60 extracted premolar teeth were cut at the level of cementoenamel junction (cej). root canals were filled with gutta-percha and filling of the coronal 2/3 of the root canals was subsequently removed to f...