18F-FDG positron autoradiography with a particle counting silicon pixel detector
18F-FDG positron autoradiography with a particle counting silicon pixel detector
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DOI：
10.1088/0031-9155/53/21/022
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发表时间：
2008-11-07
影响因子：
3.5
通讯作者：
Lastoria, S.
中科院分区：
文献类型：
--
作者：
Russo, P.;Lauria, A.;Lastoria, S.
我们报告的Medipix 2系列的室温粒子计数硅像素探测器作为探测器单元的正电子放射自显影（AR）系统，用于PET研究中使用的F-18-FDG放射性药物标记的样品的测试。硅探测器（1.98厘米（2）敏感面积，300 μ m厚）具有高的固有分辨率（55 μ m间距），并通过计数在一定的能量阈值以上的像素中的所有命中。目前的工作扩展了探测器的特性与F-18-FDG以前的文件。分析了系统的线性度、动态范围、灵敏度、本底计数率、噪声以及对生物样品的成像性能。已在实验室中用F-18-FDG滴剂（37-37 000 Bq初始活性）和离体注射88.8 MBq F-18-FDG的大鼠中进行了测试。在检测器体积中相互作用的粒子在像素簇中产生命中，该像素簇的平均大小在11 keV阈值下为4.3像素/事件，在37 keV阈值下为2.2像素/事件。结果表明，对β（+）的灵敏度为0.377 cps Bq（-1），动态范围至少为5个数量级，检测下限为0.0015 Bq mm（-2）。在500-1000 s曝光时间内，对大鼠脑薄切片（10-20 μ m）进行了F-18-FDG正电子实时AR成像，并与相邻切片的20 h胶片放射自显影进行了比较。对大鼠脑切片的图像对比度和信噪比的分析表明，泊松噪声限制成像可以在短时间内（例如，G. 100 s）曝光，具有类似于100 Bq切片活性，并且硅像素探测器产生的图像质量高于基于胶片的AR。
We report on tests of a room-temperature particle counting silicon pixel detector of the Medipix2 series as the detector unit of a positron autoradiography (AR) system, for samples labelled with F-18-FDG radiopharmaceutical used in PET studies. The silicon detector (1.98 cm(2) sensitive area, 300 mu m thick) has high intrinsic resolution (55 mu m pitch) and works by counting all hits in a pixel above a certain energy threshold. The present work extends the detector characterization with F-18-FDG of a previous paper. We analysed the system's linearity, dynamic range, sensitivity, background count rate, noise, and its imaging performance on biological samples. Tests have been performed in the laboratory with F-18-FDG drops (37-37 000 Bq initial activity) and ex vivo in a rat injected with 88.8 MBq of F-18-FDG. Particles interacting in the detector volume produced a hit in a cluster of pixels whose mean size was 4.3 pixels/event at 11 keV threshold and 2.2 pixels/event at 37 keV threshold. Results show a sensitivity for beta(+) of 0.377 cps Bq(-1), a dynamic range of at least five orders of magnitude and a lower detection limit of 0.0015 Bq mm(-2). Real-time F-18-FDG positron AR images have been obtained in 500-1000 s exposure time of thin (10-20 mu m) slices of a rat brain and compared with 20 h film autoradiography of adjacent slices. The analysis of the image contrast and signal-to-noise ratio in a rat brain slice indicated that Poisson noise-limited imaging can be approached in short (e. g. 100 s) exposures, with similar to 100 Bq slice activity, and that the silicon pixel detector produced a higher image quality than film-based AR.