A new gamma camera was designed to reduce edge effect that can occur in conventional gamma cameras and
increase the useful field of view (UFOV). In order to reduce edge effect and increase UFOV, a new gamma camera
was designed to collect light incident on the side of the scintillator by plaing an additional photosensor used
in the conventional gamma camera to prevent the occurrence of edge effect. DETECT2000 was used to evaluate
the useful field of view of the desinged gamma camera and the conventional gamma camera. As a result, the
UFOV of the new gamma camera was improved by about 95.8 % compared to the UFOV of the conventional
gamma camera. If the results of this study are used when designing a gamma camera, it is considered that edge
effects can be prevented and an expanded UFOV can be achieved.