基于SiPM的PET探测器设计及插值对PET成像结果的影响

发布时间：2018-02-28 01:19

本文关键词： 正电子发射计算机断层扫描(PET) 数据插值图像重建原始数据硅基光电倍增管(SIPM)　出处：《河北大学》2013年硕士论文　论文类型：学位论文

【摘要】：小动物正电子发射断层(positron emission tomography, PET)成像实现了在活体上的分子水平显像,是研究分子影像的尖端设备,正成为动物模型研究的强有力工具。PET设备在肿瘤及心脑血管疾病诊断、研究和新型药物研发中具有重要作用及广泛应用前景。PET探测器和电路设计是系统设计的重要组成部分,本文着重描述了探测器模块、地址编码及前端电路的设计和实现。 1.硅光电倍增管(SiPM,也称为盖革模式的雪崩二极管)可以很好地兼容核磁共振成像(MRI),并且具有和光电倍增管媲美的增益和时间特性,是一种非常有前景的可以作为PET和PET/MRI的探测器的半导体光电传感器。在本文综述了硅基光电倍增管相比传统的光电倍增管的优势,同时对基于硅基光电倍增管的小动物PET的发展趋势进行了讨论。 2.正电子发射断层成像设备探测器采集到的数据需要进行数据处理,把原始数据转换成正弦图形式的数据才能被用于图像重建。平行束断层重建和扇形束图像重建是图像重建的两种方法,分别对应平行束和扇形束形式的数据处理方法。对原始数据的操作不可避免的破坏了原始数据的完整性。现今,正电子发射断层设备在重建过程中普遍采用平行束重建的方法。平行束的数据分离会对PET数据进行插值操作,扇形束的数据分离不会对PET数据进行插值操作。本文通过对比平行束图像重建和扇形束图像重建结果,研究了数据插值对PET图像重建结果的影响。 3.我们在实现过程中使用了LYSO闪烁晶体耦合SiPM (Silicon Photomultiplier)光电探测器的探测器模块结构设计,探测器系统由27个探测器模块排列成圆环状,有8个断层。为了满足小动物PET对分辨率的高要求,我们在探测器结构上采用了新的提高分辨率的技术。
[Abstract]:Positron emission tomography (pet) imaging in small animals, which realizes molecular level imaging in vivo, is a cutting-edge device for the study of molecular imaging and is becoming a powerful tool for animal model research. Pet equipment is being used in the diagnosis of tumors and cardiovascular and cerebrovascular diseases. PET detector and circuit design is an important part of system design. This paper mainly describes the design and implementation of detector module, address code and front-end circuit. 1. The silicon photomultiplier tube, SiPM-also known as an avalanche diode in the Geiger mode, is well compatible with the magnetic resonance imaging (MRI) and has gain and time characteristics comparable to those of the photomultiplier tube. Silicon based photomultiplier is a promising semiconductor photomultiplier that can be used as a detector for PET and PET/MRI. In this paper, the advantages of silicon based photomultiplier compared with traditional photomultiplier are reviewed. The development trend of small animal PET based on silicon based photomultiplier tube is also discussed. 2. The data collected by the detector of the positron emission tomography equipment need to be processed. Only when the original data is converted into sinusoidal image can it be used in image reconstruction. Parallel beam fault reconstruction and sector beam image reconstruction are two methods of image reconstruction. The operation of the raw data inevitably destroys the integrity of the original data. Parallel beam reconstruction is widely used in positron emission tomography equipment. Data separation of parallel beams interpolates PET data. The data separation of sector beam does not interpolate PET data. In this paper, the effect of data interpolation on PET image reconstruction is studied by comparing the results of parallel beam image reconstruction and sector beam image reconstruction. 3. We use LYSO scintillation crystal coupled SiPM silicon photomultiplier to design the detector module structure. The detector system is arranged into a circular ring by 27 detector modules. There are 8 faults. In order to meet the high resolution requirements of small animal PET, we have adopted a new technique to improve the resolution of the detector structure.
【学位授予单位】：河北大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R318.6;TP391.41

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