The quality of gamma camera images is determined by the characteristics of the image collimator. The size and
length of the collimator’s holes, as well as the thickness of its septa, directly impact sensitivity and spatial resolution.
These factors have conflicting optimization relationships with each other, and sensitivity and spatial resolution
variations manifest differently based on combinations of different variables such as larger or smaller
diameter holes, shorter or longer holes, thinner or thicker septa, and so on. Accordingly, appropriate collimator
design plays a crucial role in optimizing the quality of gamma camera images. In this study, referencing the
structure of an ELEGP collimator, we design a collimator that optimizes sensitivity and spatial resolution. To
achieve this, collimators with various hole sizes, lengths, and septa thicknesses were designed, and simulations
were conducted. Through this process, the most suitable conditions for optimizing the image quality of the
gamma camera system were obtained. Geant4 Application for Tomographic Emission (GATE) simulations
were performed for collimator optimization. Among 820 simulation results, the best image quality was achieved
with a hole diameter of 2.6 mm, length of 28 mm, and septa thickness of 0.4 mm. If the collimator designed in
this study is used, it is expected to provide superior images compared to those obtained with existing gamma
camera systems.