Development of Ultra-high Resolution Single Photon Emission Computed Tomography(SPECT) Using Pinhole-Collimator

使用针孔准直器的超高分辨率单光子发射计算机断层扫描 (SPECT) 的开发

• 批准号: 04680235
• 负责人: MUKAI Takao
• 金额: $ 1.34万
• 依托单位: Kyoto College of Medical Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04680235/
• 关键词: Pinhole collimator; Single Photon Emission CT (SPECT); Gamma Camera; Radiopharmaceutical; Blood Flow; Neuro Transmitter; Neuro Receptor; ガメマカメラ; ピンホールコリメーター; 放射性化合物

Radionuclide imaging of small animals is useful for development of the radiopharmaceuticals as well as for studying various animal disease models. Although todays SPECT systems provide an excellent resolution(8-10mm), these are not sufficient for small animal studies including rats, mice and gerbils.In order to achieve less than 2mm spatial resolution, we have attempted to construct an ultra-high resolution SPECT system using pinhole collimators. The pinhole collimator were made of cone shaped lead shield and tungsten pinhole with effective aperture size of 1.0 and 2.0mm. Four pinhole collimators are attached to 4-head SPECT scanner with fixed distance from pinhole to camera (130mm) and from pinhole to rotating axis (50mm). The field of view was 50mm in diameter and 12.3mm in axial direction with minimum slice thickness of 0.51mm. Filtered back projection algorithm was used to reconstruct SPECT images after fan-parallel projection data conversion.The system provided spatial resolution of 1.65mm (FWHM) and sensitivity of 116 cps/kBq/ml with 1.0mm pinhole collimator. In animal studies by rats with Tc-99m blood flow tracers, brain structures and myocardial wall were resolved clearly. Dynamic SPECT imaging of benzodiazepine receptor in rat brain showed the meaning time activity curves at every region of the brain.This ultra-high resolution pinhole SPECT system will contribute to development of new radiopharmaceuticals and disease models in living animals.

小动物的放射性核素成像可用于开发放射性药物以及研究各种动物疾病模型。尽管当今的SPECT系统提供了出色的分辨率（8-10mm），但这对于包括大鼠、小鼠和沙鼠在内的小动物研究来说还不够。为了实现小于2mm的空间分辨率，我们尝试构建超高分辨率SPECT使用针孔准直器的系统。针孔准直器由锥形铅罩和钨针孔制成，有效孔径尺寸为1.0和2.0mm。四个针孔准直器连接到 4 头 SPECT 扫描仪，从针孔到相机 (130mm) 以及从针孔到旋转轴 (50mm) 的距离固定。视场直径为50mm，轴向为12.3mm，最小切片厚度为0.51mm。扇形平行投影数据转换后，采用滤波反投影算法重建SPECT图像。系统采用1.0mm针孔准直器，提供1.65mm（FWHM）的空间分辨率和116 cps/kBq/ml的灵敏度。在使用 Tc-99m 血流示踪剂对大鼠进行的动物研究中，大脑结构和心肌壁清晰可见。大鼠大脑中苯二氮卓受体的动态SPECT成像显示了大脑每个区域的有意义的时间活动曲线。这种超高分辨率针孔SPECT系统将有助于开发新的放射性药物和活体动物疾病模型。