Positron tomography plane detection system
|Keywords||Positron Emission Tomography(PET) Scintillation crystal Position sensitive photomultiplier tube (PS-PMT) Mento Carlo simulation|
PET (Positron Emission Tomography) is one of the most important imaging tools in the field of medical imageology. From the level of molecular in living body, PET gives functional information about specific area of the body by three dimensional pictures, as compared to the structural pictures by other imaging tools. The basic idea of Positron imaging is injected chemical compounds labeled with positron-emitting nuclides into a body, then the distribution of the nuclides from the annihilation of positron and electron can be measured. The specificity and high sensitivity make PET to be a powerful means for studying molecular pathways and the processes of biochemical reactions.The BGO (bismuth germanate) scintillation crystal coupled with a position sensitive photomultiplier tube R5900-00-M64 are used to build the y -ray detector ,.The planar y -ray imaging system is just composed of two such block detectors mainly for plant studies. The circuit driving system for mechanical plate is designed . Also deep research of scintillation crystal and PS-PMT is made during the experiment, some method of measurement of the characteristics of scintillation crystal and position sensitive photomultiplier tubes is discussed and brought in experiment. AT last, the open questions are brought forward , the research are summarized and expected in this paper.The choice of the reflector, coupling material and optical condition of the crystals are the dominated factors affecting the light signal from the scintillator. In order to obtain optimal method to build the scintillation block, the simulation study of the light collection from Nal, BGO, LSO, GSO, YSO scintillator is carried out by means of Monte Carlo method. Besides, the Monte Carlo simulation of y -rays transference in the scintillation block is taken and study of energy resolution of BGO scintillator is carried out.Different spatial position histogram of scintillator arrays are taken with the MicroPET planar system with a 22Na source. All these work lay a good foundation for the later research of MicroPET.