Preliminary evaluation of the tomographic performance of the mediSPECT small animal imaging system
Preliminary evaluation of the tomographic performance of the mediSPECT small animal imaging system
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DOI：
10.1016/j.nima.2006.10.123
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发表时间：
2007-02
影响因子：
1.4
通讯作者：
R. Accorsi;A. S. Curion;P. Frallicciardi;R. Lanza;A. Lauria;G. Mettivier;M. Montesi;P. Russo
中科院分区：
文献类型：
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作者：
R. Accorsi;A. S. Curion;P. Frallicciardi;R. Lanza;A. Lauria;G. Mettivier;M. Montesi;P. Russo
我们报告了那不勒斯大学和 INFN 开发的原型 (MediSPECT) 系统的测试，该系统用于对具有小视场 (FoV) 和高空间分辨率的小动物进行单光子发射计算机断层扫描 (SPECT) 成像。 MediSPECT 是一种 SPECT 成像系统，基于 1 毫米厚的 CdTe 像素探测器，凸块接合到以单光子计数运行的 Medipix2 CMOS 读出电路。 CdTe探测器具有256×256像素方阵，像素间距为55μm，敏感区域为14×14mm2。在当前版本中，该系统采用安装在旋转龙门架上的单个探测器头。为了对采集设备和图像重建算法进行初步测试和校准，以步进拍摄模式采集了 90 个 γ 射线点源（109Cd）通过单个针孔（直径 0.4mm；旋转半径约 2.5cm；焦距约 4.5cm）的投影，每个投影 20 分钟。将直径800μm的毛细血管排列成Y形，形成更复杂的体模（125I，针孔直径1mm，45个投影，每个投影25分钟）。使用实现标准 OS-EM 的自定义算法重建图像，并进行旋转中心校正，并在 2mm 的 FoV 上获得 0.2mm 的空间分辨率。
We report on the tests of a prototype (MediSPECT) system developed at University & INFN Napoli, for Single Photon Emission Computed Tomography (SPECT) imaging on small animals with a small Field of View (FoV) and high spatial resolution. MediSPECT is a SPECT imaging system based on a 1-mm-thick CdTe pixel detector, bump-bonded to the Medipix2 CMOS readout circuit operating in single-photon counting. The CdTe detector has 256×256 square array of pixels arranged with a 55μm pitch, for a sensitive area of 14×14mm2. In its present version, this system implements a single detector head, mounted on a rotating gantry. For preliminary testing and calibration of the acquisition equipment and image reconstruction algorithms, 90 projections of a γ-ray point source (109Cd) through a single pinhole (diameter 0.4mm; radius of rotation about 2.5cm; focal length about 4.5cm) were acquired for 20min each in a step-and-shoot mode. Capillaries, 800μm in diameter, were arranged in a Y-shape to form a more complex phantom (125I, 1mm pinhole diameter, 45 projections, each acquired for 25min). Images were reconstructed with a custom algorithm implementing standard OS-EM with center of rotation correction and spatial resolution of 0.2mm over a FoV of 2mm was obtained.