Development of novel and low-cost readout electronics for large FOV gamma camera detector

Abstract

Abstract Objective: Gamma cameras based on scintillation crystals play a crucial role in nuclear medicine. We designed a readout method for a large field-of-view (FOV) gamma detector, reducing N × M analog signals of photomultiplier tubes (PMTs) to N + M analog sums of each row and column, thus improving complexity and cost considerations while preserving image quality. Methods: In this study, we developed a gamma detector consisting of 48 square PMTs using novel readout electronics, reducing 6 × 8 to 6 + 8 analog signals. All 14 analog signals were converted to digital signals using AD9257 high-speed analog to digital converters (ADC) driven by the SPARTAN-6 family of field-programmable gate arrays (FPGA) in order to calculate the signal integrals. The positioning algorithm was based on the digital correlated signal enhancement (CSE) algorithm, which was implemented in the acquisition software. The performance characteristics of the developed gamma camera were measured using the NEMA NU1 standard. Results: The measured energy resolution in the developed detector was 8.7%, intrinsic spatial resolution was 3.9 mm, uniformity was within 0.6%, and linearity was within 0.1%. Conclusions: The performance evaluation demonstrated that the developed detector has proper specifications for imaging purposes.