Basic Research on a New Generation PET system (Semiconductor Three Dimensional PET) toward Ultra Low Dose and High Spatial Resolution

面向超低剂量和高空间分辨率的新一代 PET 系统（半导体三维 PET）的基础研究

• 批准号: 11558060
• 负责人: ISHII Keizo
• 金额: $ 8.83万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11558060/
• 关键词: Ultra low Dose PET; New Generation PET; Semiconductor 3D-PET; Whole Body PET; Image Reconstruction for 3D-PET; 3次元TPE画像再構成法

First, the performance of several types of semiconductor detectors was inveatigated aiming at the development of a high resolution PET system using semiconductor detectors. The detectors of TIBr of three different shapes (a thin detector 12mm^2×0.47mm, a block type detector 9mm^2×3mm and a laminated type detector 16mm^2×0.5mm×10 pieces) were made, and their performance was evaluated. The peak of 0.511ke V was obtained with the thin detector. This peak was not observed with the other TIBr detectors, due to a large noise appearing at the low energy side.Second, the time resolution characteristics of CdTe semiconductors as detector foe PET were examined in parallel with the development on TLBr semiconductors. The time resoluhon of the CdTe semiconductor of 16mm^2×0.5mm for PET was 15ns.From these results, it is shown that at present, the CdTe detector is suitable as detector for a small semiconductor PET, and the use of thin detector crystals allows obtaining a good time resolution.We investigated theoretically the limit of spatial resolution for a PET system and obtained a spatial resolution limit of 0.8mm in the case of gantry diameter 25cm. Based on the present results, we built a mini-semicomductor PET, opposing the detector blocks consisting of CdTe crystals of 0.5×5×5mm^3 in four rows of two layers at 2.4mm intervals (16 detectors in total). The hyperfine structure Phantom that consisted of two or more^<22>Na hot spots of 1mm and 0.6mm diameter was tested, and the PET image of these spots was separated with a spatial resolution of 0.5mm.This is the first high resolution PET device to date and demonstrates that considerable improvement in spatial resolution can be obtained compared to existing PET facilities.

首先，对几种半导体探测器的性能进行了研究，目的是开发高分辨率的PET系统。制作了三种不同形状的TIBr探测器（12mm^2×0.47mm薄片探测器、9mm^2×3mm块型探测器和16mm^2×0.5mm×10层合型探测器），并对其性能进行了评价。用薄探测器测得0.511ke V的峰。由于在低能侧出现了很大的噪声，其他TIBr探测器没有观察到这个峰。其次，结合TLBr半导体的发展，考察了CdTe半导体作为PET探测器的时间分辨特性。16mm^2×0.5mm的CdTe半导体对PET的时间分辨率为15ns。这些结果表明，目前CdTe探测器适合作为小型半导体PET的探测器，并且使用薄探测器晶体可以获得良好的时间分辨率。我们从理论上研究了PET系统的空间分辨率极限，得到了龙门直径为25cm时的空间分辨率极限为0.8mm。基于目前的结果，我们构建了一个微型半导体PET，相对于由0.5×5×5mm^3的CdTe晶体组成的探测器块，以2.4mm的间隔组成四排两层（共16个探测器）。测试由两个或多个直径为1mm和0.6mm的^<22>Na热点组成的超精细结构Phantom，并以0.5mm的空间分辨率分离这些热点的PET图像。这是迄今为止第一个高分辨率PET设备，表明与现有PET设备相比，可以获得相当大的空间分辨率改进。

项目成果

Nagasawa M.,Suguki A.,Ishii K.Yamagaki H.,Matsugama S. et al: "Phase Correction Analysis between EEG and MEG Simultanuously Measured by a simple System Composed of one-channel SQULD Fluxeseter and true-channel EEG device"CYRIC Annual Repoct 1999. 91-96 (2

Nagasawa M.,Suguki A.,Ishii K.Yamagaki H.,Matsugama S.等人：“由单通道 SQULD Fluxseter 和真通道 EEG 装置组成的简单系统同时测量 EEG 和 MEG 之间的相位校正分析”CYRIC

T.Mizuta et al.: "A boundary Formation Method Using a Median Filter Processing for Attenuation Correction in 3D-PET"CYRIC Annual Report 1999. 82-90 (2000)

T.Mizuta 等人：“使用中值滤波器处理进行 3D-PET 衰减校正的边界形成方法”CYRIC 年度报告 1999. 82-90 (2000)

四月朔日聖一,藤原竹彦,石井慶造,伊藤正敏,北村圭司: "全身用ポジトロン断層撮影装置(島津:SET-2400W)の2次元および3次元データ収集画像の分解能とカウント・リカバリ係数の測定"核医学. 37巻1号. 35-41 (2000)

Seiichi Shigatsu、Takehiko Fujiwara、Keizo Ishii、Masatoshi Ito、Keiji Kitamura：“全身正电子断层扫描设备（岛津：SET-2400W）的 2D 和 3D 数据收集图像的分辨率和计数恢复系数”测量“核医学”。第 37 卷，第1期。35-41（2000）

Mizata T.,Ishii K.,Yamagaki H.Matsuyama S.,Oishi Y.,Itoh M.,Yamaguchi K. et al: "A Boundary Formation Method Using a Median Filter Processing for Attonuation Correction in 3 D-PET"CYRIC Annual Report 1999. 82-90 (2000)

Mizata T.、Ishii K.、Yamagaki H.Matsuyama S.、Oishi Y.、Itoh M.、Yamaguchi K. 等人：“使用中值滤波器处理进行 3 D-PET 衰减校正的边界形成方法”CYRIC 年刊

M.Iemitsu, M.Itoh et al.: "Regional Cardiac Glucose Metabolism During Running Measured by 3D Positron Emission Tomography in Human"Adv.Exerc.Sports Physiol.. 17. 53-58 (2001)

M.Iemitsu、M.Itoh 等人：“通过 3D 正电子发射断层扫描测量人类跑步期间的区域心脏葡萄糖代谢”Adv.Exerc.Sports Physiol.. 17. 53-58 (2001)