Performance evaluation of the microPET R4 PET scanner for rodents
Performance evaluation of the microPET R4 PET scanner for rodents
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DOI：
10.1007/s00259-002-1052-6
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发表时间：
2003-05-01
影响因子：
9.1
通讯作者：
Heiss, WD
中科院分区：
文献类型：
--
作者：
Knoess, C;Siegel, S;Heiss, WD
microPET R4扫描仪是用于啮齿动物研究的专用正电子发射断层扫描仪（PET）。在这项工作中确定了许多扫描仪参数，如空间分辨率，灵敏度，散射和计数率性能，这表明microPET R4是一种适合小鼠和大鼠等小动物的PET扫描仪。在视场（FOV）的中心处，由锗-68线源在250-750 keV的能量窗口内的测量计算出中心点源的最大灵敏度为43.66 cps/kBq。用直径为1 mm的钠-22点源在中心测量轴向方向的半高宽（FWHM）为1.85 mm，轴向方向的FWHM为1.66 mm的空间分辨率。在FOV的内部20 mm内，体积分辨率优于15.6穆尔，对应于在所有三个维度上小于2.5 mm的线性分辨率。高分辨率体模图像以及小鼠和大鼠研究的图像说明了扫描仪的良好性能。最大噪声等效计数率（NECR）达到174 kcps的小鼠体模和93 kcps的大鼠体模（能量窗口250-750 keV）。对于250-750 keV的能量窗口和与小鼠和大鼠相似的体模直径，测量的散射分数在0.30和0.42之间。与用于灵长类动物的microPET P4模型的比较说明了由于较小的探测器环直径而导致的灵敏度增益以及NECR的变化。
The microPET R4 scanner is a dedicated positron emission tomograph (PET) for studies of rodents. A number of scanner parameters such as spatial resolution, sensitivity, scatter, and count rate performance were determined in this work, which showed that the microPET R4 is a suitable PET scanner for small animals like mice and rats. In the center of the field of view (FOV) a maximal sensitivity of 43.66 cps/kBq for a centered point source was calculated from a measurement with a germanium-68 line source within an energy widow of 250-750 keV. A spatial resolution of 1.85 mm full-width at half-maximum (FWHM) in the axial direction and 1.66 mm FWHM in the transaxial direction was measured in the center with a 1-mm-diameter sodium-22 point source. Within the inner 20 mm of the FOV the volumetric resolution is better than 15.6 mul, corresponding to a linear resolution of less than 2.5 mm in all three dimensions. Images of a high-resolution phantom and from mice and rat studies illustrate the good performance of the scanner. A maximal noise equivalent count rate (NECR) was reached at 174 kcps for a mouse phantom and at 93 kcps for a rat phantom (energy window 250-750 keV). Scatter fractions were measured between 0.30 and 0.42 for an energy window of 250-750 keV and phantom diameters similar to mice and rats. A comparison with the microPET P4 model for primates illustrates the gain in sensitivity due to a smaller detector ring diameter but also the changes in NECR.