3D-localization of single point-like gamma sources with a coded aperture camera.

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Surgical Guidance

Background:

• 3D localization of gamma sources can enhance radio-guided surgery outcomes.
• Coded aperture cameras offer a potential solution for improved gamma source localization.

Purpose of the Study:

• To analyze the localization accuracy of point-like gamma sources using a single coded aperture camera.
• To compare different 3D source positioning methods.

Main Methods:

• Simulated and measured data of an Americium-241 (Am-241) point source at 17 positions.
• Utilized a Tungsten coded aperture mask (MURA rank 31) and a Timepix3 detector.
• Compared iterative search with Gaussian fitting, exponentially modified Gaussian (EMG) fitting, and center of mass methods for 3D localization.

Main Results:

• The EMG fitting method improved localization accuracy by a factor of 4 compared to Gaussian fitting in simulated data.
• Achieved a mean localization error of 0.77mm for simulated data and 2.64mm for experimental data.
• Localization accuracy was evaluated within an imaging range of 20-100mm.

Conclusions:

• Point-like gamma sources in the near-field can be accurately localized with a single coded aperture camera, comparable to stereo cameras.
• Despite limitations in axial resolution, the technology shows promise for surgical applications.
• Further research is needed to understand the impact of source size and photon count on imaging and localization accuracy.