National Electrical Manufacturers Association NU-4 Performance Evaluation of the PET Component of the NanoPET/CT Preclinical PET/CT Scanner
National Electrical Manufacturers Association NU-4 Performance Evaluation of the PET Component of the NanoPET/CT Preclinical PET/CT Scanner
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DOI：
10.2967/jnumed.111.088260
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发表时间：
2011-11-01
影响因子：
9.3
通讯作者：
Marsden, Paul K.
中科院分区：
文献类型：
--
作者：
Szanda, Istvan;Mackewn, Jane;Marsden, Paul K.
NanoPET/CT代表了最新一代的商业临床前PET/CT系统。本文介绍了根据国家电气制造商协会(NEMA)NU-4 2008标准对系统中的PET组件进行的性能评估。方法：NanoPET/CT由12个正硅酸锶：铈模块探测器组成，1个环，轴向覆盖9.5 cm，动物口16 cm。每个探测器晶体的尺寸为1.12×1.12×13 mm，1个模块包含81×39个此类晶体。光学光导将闪烁光传输到平板多阳极位置灵敏光电倍增管。模数转换卡和基于现场可编程门阵列的数据采集卡提供读出。根据NEMA NU-4标准对空间分辨率、灵敏度、计数速率能力和图像质量进行评估。除了标准外，还进行了能量和时间分辨率测量以及小鼠成像研究。结果：511keV能量分辨率为19%。空间分辨率在单层反投影/过滤反投影重建图像上以半高全宽测量，轴向接近1 mm，在轴向中心和四分之一视野处的中央5 cm横轴区均保持在2.5 mm以下。视场中心点源的最大绝对灵敏度为7.7%。对于小鼠和大鼠大小的模体，最大噪声当量计数率在36MBq和27MBq时分别为430kcps和130kcps。用图像质量模型测量了均匀系数和恢复系数，得到了高质量的图像。在一项用F-18标记的甲状腺特异性示踪剂进行的小鼠研究中，尽管甲状腺的大小很小，但甲状腺的两个叶是明显可区分的。灵活的读出系统允许以高效的方式进行实验，并且系统始终保持稳定。结论：探测器晶体数量多，间距细小，具有良好的空间分辨率，是目前商用系统中最好的报道。绝对灵敏度在视场范围内很高。结合出色的图像质量，这些特点使NanoPET/CT成为临床前研究的有力工具。
The NanoPET/CT represents the latest generation of commercial preclinical PET/CT systems. This article presents a performance evaluation of the PET component of the system according to the National Electrical Manufacturers Association (NEMA) NU-4 2008 standard. Methods: The NanoPET/CT consists of 12 lutetium yttrium orthosilicate: cerium modular detectors forming 1 ring, with 9.5-cm axial coverage and a 16-cm animal port. Each detector crystal is 1.12 x 1.12 x 13 mm, and 1 module contains 81 x 39 of these crystals. An optical light guide transmits the scintillation light to the flat-panel multianode position-sensitive photomultiplier tubes. Analog-to-digital converter cards and a field-programmable gate array-based data-collecting card provide the readout. Spatial resolution, sensitivity, counting rate capabilities, and image quality were evaluated in accordance with the NEMA NU-4 standard. Energy and temporal resolution measurements and a mouse imaging study were performed in addition to the standard. Results: Energy resolution was 19% at 511 keV. The spatial resolution, measured as full width at half maximum on single-slice rebinning/filtered backprojection-reconstructed images, approached 1 mm on the axis and remained below 2.5 mm in the central 5-cm transaxial region both in the axial center and at one-quarter field of view. The maximum absolute sensitivity for a point source at the center of the field of view was 7.7%. The maximum noise equivalent counting rates were 430 kcps at 36 MBq and 130 kcps at 27 MBq for the mouse-and rat-sized phantoms, respectively. The uniformity and recovery coefficients were measured with the image-quality phantom, giving good-quality images. In a mouse study with an F-18-labeled thyroid-specific tracer, the 2 lobes of the thyroid were clearly distinguishable, despite the small size of this organ. The flexible readout system allowed experiments to be performed in an efficient manner, and the system remained stable throughout. Conclusion: The large number of detector crystals, arranged with a fine pitch, results in excellent spatial resolution, which is the best reported for currently available commercial systems. The absolute sensitivity is high over the field of view. Combined with the excellent image quality, these features make the NanoPET/CT a powerful tool for preclinical research.