PET Detector And List-Mode Map Design Based On SiPM

PET (Positron Emission Tomography) is the highest level of functional imagingtechnology in nuclear medicine field. PET systems have important effect and the prospect ofapplication in many filed, such as diagnose and research in cancer, angiocardiopathy andcerebrovascular disease, development of new drugs. PET detector and electronics design is animportant part of the system design. This paper describes the detector module, address codingand the front-end electronics design and implementation.The PET detector ring is arranged by several detector modules. The detector slicenumber and the thickness of every slice determine the axial vision of PET system. Thedetector module in the detector ring determine the PET system the resolution. The detectormodule usually contains several crystal coupling photodetector blocks. The scintillator crystalreceiving γ photonic and convert it to light. The photodetector convert the light to electricalsignals, which supply for the electronics processing.The connections between coincidence detectors called Line-Of-Response. The LOR canreflect the annihilating events position information. Coding all LOR form the List-Mode map,the List-Mode map have to ensure that one LOR corresponding one code only. The List-Modemap is used in coincidence electronics and data processing, it’s a necessary part of the PETsystem.The front-end electronics include amplification, time information extraction, coincidenceidentify, output coding parts. The detector output signal is usually very weak and need anamplification processing. Extracted different detector output signal time information, Identifydifferent time information in coincidence time window. This process called electroniccollimation. A pair of coincidence signals corresponding an annihilating event. Coincidenceelectronics coding the event by the List-Mode map, the coincidence code send to computerfor data processing.We used LYSO scintillator coupling SiPM (Silicon Photomultiplier) in the detector module design.27detector modules arranged the detector ring, which have eight slice. ManyFPGAs and ASICs are used in front-end electronics, which greatly reduce the circuitrycomplexity, and increase the circuit flexibility. In order to meet the high resolutionrequirements in small animal PET, we use a cross-crystal technology in the detector moduledesign to improve spatial resolution, this technology has declared national invention patent.