Modelling and Image Reconstruction Evaluation of a Scintillation Camera with Silicone Photomultiplier

Background: Recent research on photon detection has led to the introduction of a silicone photomultiplier (SiPM) that operates at a low voltage and is insensitive to magnetic fields. Objective: This work aims to model a scintillation camera with a SiPM sensor and to evaluate the camera reconstructed images from gamma ray projection data.Material and Methods: The type of study in this research is experimental work and analytical. The scintillation camera, modelled from an SiPM sensor array SL۴-۳۰۰۳۵, coupled with a scintillation material Caesium Iodide doped with Thallium (CsI(Tl)), is used in the experimental part. The performance of the camera was evaluated from reconstructed images by a back-projection technique of a radioactive source Caesium-۱۳۷ (Cs-۱۳۷). Results: The experiments conducted with a ۱ µCi Cs-۱۳۷ radioactive source have revealed that the bias voltage (Vbias) of the SiPM needs to be set to ۲۷.۸ V at an operating temperature between ۴۳ °C to ۴۴ °C. The radioactive source has to be placed within a ۱ cm distance from the sensor to obtain the optimum projection data. Finally, the back-projection technique for image reconstruction with linear interpolation pre-processing has revealed that the Ram-Lak filter produces a better image contrast ratio compared to others. Conclusion: This research has successfully modelled a scintillation camera with SiPM that was able to reconstruct images with an ۸۶.۴% contrast ratio from gamma ray projection data.

Keywords:

Gamma Cameras , Silicone Photomultiplier (SiPM) , Photomultiplier Tubes (PMT) , Image reconstruction , Filter Back-Projection , Radionuclide Imaging , Scintillation Counting