The Design Of High Spatial Resolution Animal PET Detector Based On SiPM

Positron Emission Tomography(PET)is a sophisticated non-invasive imaging tech-nique.It could provide the biochemical reactions,metabolic activities and biological activi-ties quantitatively and dynamically.It plays a significant role in the diagnosis and treatment of oncology,cardiovascular disease and nervous system,as well as in the fields of biomed-ical research and drug development.The main content of this thesis is the design of high spatial resolution detector based on Silicon Photomultiplier(SiPM)and digital PET technology.As a semiconductor photomul-tiplier ASIC,SiPM has the advantages of small package,low-cost,high gain,low supply voltage,and insensitivity to magnetic fields.In the PET design,SiPM is gradually replacing the photomultiplier tube(PMT)as a new generation of basic components.Due to the small package of the SiPM array,a large number of channels will be used when building a PET system.In order to reduce the number of channels and increase system integration to sim-plify its complexity,this thesis applies channel multiplexing to SiPM arrays,and multiplexes72 SiPMs signals into 5 signals outputs.A cutting light guide is used in the detector unit to improve the performance of the detector.In digital signal acquisition,a multi-threshold voltage method based on prior information is applied to electronics design.A gain adaptive method is proposed to reduce the application difference of SiPM arrays which is the same model and different gain.A PET detector ring experiment setup is built to evaluate its performance.The detector module designed in this thesis has a detection area of 106×53mm~2.Finally,the performance of the detector module is evaluated.All the crystal can be clearly resolved in teh position map.The average energy resolution of the module is 14.7%@511keV,and the PET detector has a time resolution of 1.4ns while the basic detection unit has a 1.1ns resolution.A spatial resolution of 1.0mm was obtained by using a micro-Derenzo phantom.