System design of a small OpenPET prototype with 4-layer DOI detectors

Area of Science:

• Nuclear Instrumentation
• Medical Imaging Physics

Background:

• In-beam Positron Emission Tomography (PET) requires specialized detector geometries for simultaneous imaging during particle therapy.
• Existing PET systems face challenges in accommodating the open geometry needed for in-beam applications.

Purpose of the Study:

• To present the design and performance evaluation of a small-scale OpenPET prototype.
• To demonstrate the feasibility of in-beam PET imaging using the developed prototype.

Main Methods:

• Designed a prototype with two axially separated detector rings, each featuring 8 depth-of-interaction detectors.
• Utilized 784 Lutetium(2x)Gadolinium(2(1-x))SiliconOxide:Cerium (LGSO) crystals per detector in a 4-layer configuration, coupled to position-sensitive photomultiplier tubes (PS-PMTs).
• Implemented signal processing techniques including 2D position histograms and separated front-end electronics to mitigate radiation damage and reduce system scale.

Main Results:

• Achieved sufficient LGSO crystal identification and negligible crosstalk between detectors.
• Demonstrated timing resolution of 3.0 ns and energy resolution of 14%.
• Observed minimal random coincidences, indicating suitability for in-beam PET experiments despite minor timing shifts due to coaxial cables.

Conclusions:

• The OpenPET prototype exhibits promising performance characteristics for in-beam PET imaging.
• The design effectively addresses challenges related to detector geometry and radiation exposure.
• The system holds potential for advancing simultaneous imaging capabilities in particle therapy settings.