A Study of Counting Efficiency according to the Window-width on Radionuclides $^{131}I$ and $^{99m}Tc$

방사성(放射性) 의약품(醫藥品) $^{131}I$과 $^{99m}Tc$에서 window폭(幅) 변화(變化)에 따른 계수(計數)의 변화비교(變化比較)에 관(關)한 검사(檢討)

It is an experimental report about optimum window-width on radionuclides $^{99m}Tc$ and $^{131}I$ and obtained results as follows; 1. In case of $^{99m}Tc$, a) The difference of counting rate in each window-width is greater at the below 20% window than above 20% window-width. b) BKG counting is proportionated to the window-width. 2. In case of $^{131}I$, a) The counting rate increased according to the window-width but the increasing course is not equal in all window. The difference of counting rate is greater at the below of 20% window-width than above 20% window. b) BKG counting is proportionated to the window-width.