三、系统规格 序号 | | | |
1 | 侦测头 | 尺寸 | 80 × 62 × 56 mm (L ×W × H). 约5 kg |
材质 | 由医疗级钨加工制成 |
闪烁晶体 | LYSO |
联机 | 两条高效率光导管,长度2 -- 10 m |
2 | 性能 | 灵敏度 | 导管内径0.28 mm: 0.2 cps/kBq/ml(小鼠) |
导管内径0.58 mm: 0.8 cps/kBq/ml(大鼠) |
导管内径1.00 mm: 2.4 cps/kBq/ml(更大个体) |
3 | 线性度 | | 6000 cps 以下完全线性(无误差),在10000 cps以上,误差小于1% |
4 | 光子侦测单元 | 光子检测装置 | 19英寸光子计数装置与采集系统 |
操作 | 可单独操作,执行系统检查与校正等功能,触摸屏实时数据显[cps] |
5 | 输入 | 辅助模拟输入 | 面板前方提供两个BNC 规格模拟讯号输入孔(0 -- 3.3 V) |
6 | 数据撷取 | 软件 | 软件PMOD 软件PSAMPLE 模块 |
操作系统 | Windows 7, XP, vista, MacOSX, Linux |
传输接口 | TCP/IP (可选配无线传输) |
四、用户名单 序号 | 客户 | 仪器数量 |
1 | University of Zurich | 1 |
2 | Federal Institute of Technology, Zurich | 1 |
3 | Research Institution Juelich Germany | 1 |
4 | University of Antwerp, Belgium | 1 |
5 | Research Institute, Paris | 1 |
6 | University of Hannover | 1 |
7 | University of Oslo | 1 |
8 | Genentech, San Francisco | 2 |
9 | Amgen Biotechnology | 1 |
五、合作伙伴PMOD Technologies Ltd. Unitectra
Zurich, Switzerland Zurich, Switzerland
University of Zurich CSEM
Zurich, Switzerland Neuchatel, Switzerland
六、药物动力学实验论文(部分摘要)Quantification of Brain Glucose Metabolism by 18F-FDG PET
with Real-Time Arterial and Image-Derived Input Function in Mice
Malte F. Alf1,2, Matthias T. Wyss3,4, Alfred Buck3, Bruno Weber4, Roger Schibli1,5, and Stefanie D. Kr?mer11Center for
Radiopharmaceutical Sciences of ETH, PSI, and USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and
Applied Biosciences, ETH Zurich, Zurich, Switzerland; 2Laboratory of Functional and Metabolic Imaging, Institute of Physics of
Biological Systems, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 3Department of Nuclear Medicine,
University Hospital Zurich, Zurich, Switzerland; 4Institute of Pharmacology and Toxicology, University of Zurich, Zurich,Switzerland;
and 5Center for Radiopharmaceutical Sciences of ETH, PSI, and USZ, Paul Scherrer Institute PSI, Villigen, Switzerla
Kinetic modeling of PET data derived from mouse modelsremains hampered by thetechnical inaccessibility of an accurateinput function (IF).
In this work, we tested the feasibility of IF measurement with an arteriovenous shunt and a coincidencecounter in mice and compared the method
with an imagederived IF (IDIF) obtained by ensemble-learning independent component analysis of the heart region. Methods: 18F-FDG brain kinetics were quantified in 2 mouse strains, CD1 and C57BL/6, using the standard 2-tissue-compartment model. Fits obtained with the 2 IFs were compared regarding their goodness of fit as assessed by the residuals, fit parameter SD, and Bland–Altman analysis. Results: On average, cerebral glucose metabolic rate was 10% higher for IDIF-based quantification.The precision of model parameter fitting was significantly higher using the shunt-based IF, rendering the quantification of single process rate constants feasible. Conclusion: We demonstrated that the arterial IF can be measured in mice with a femoral arteriovenous shunt. This technique resulted in higher precision for kinetic modeling parameters than did use of the IDIF. However,for longitudinal or high-throughput studies, the use of a minimally invasive IDIF based on ensemble-learning independent component analysis represents a suitable alternative.
Key Words: energy metabolism; PET; molecular imaging; glucose; kinetic modeling
J Nucl Med 2013; 54:1–7 DOI: 10.2967/jnumed.112.107474
PET with 18F-FDG is a commonly used method to determine glucose metabolism in animal and human tissues (1). Full quantification of 18F-FDG kinetics can be achieved by applying a 2-tissue-compartment model (2). The model requires the time course of the 18F-FDG concentration in the target organ(tissue time–activity curve) and in arterial plasma (input function, IF). In human brain PET, the IF is commonly measured from a catheter placed in the radial artery. An alternative is derivation of the IF from PET images via values measured in a volume of interest placed over the cardiac ventricles or a large vessel. A prerequisite of image-derived IFs (IDIFs) is the location of the blood pool and the organ of interest in the same field of view. In general, one or more arterial blood samples are measured to calibrate the IDIF. In a recent review article for human PET(3), the authors concluded that arterial blood sampling remains the preferred method to define the IF, because invasiveness is hardly reduced by the use of an IDIF.
In small animals, the small blood volume is the major constraint for manual blood sampling. This constraint prompted the development of several alternative methods, such as the sampling of very small volumes via a microfluidic chip (4) or the use of b-probes for measuring the blood radioactivity (5,6). Despite these new physical methods, the main research focus has been on developing the use of IDIFs, where blood radioactivity is estimated directly from the dynamic PET images. IDIF generation from simple analysis of blood pool volumes such as the liver or the heart ventricles is flawed by 18F-FDG uptake by the liver or spillover from surrounding myocardium, cardiac motion, and partial-volume effects. Compensation can be achieved to varying degrees by image processing methods such as factor analysis (7), modelbased techniques (8), independent component analysis (9), so-called hybrid IDIFs (e.g., 10,11), and cardiac gating combined with improved image reconstruction algorithms (12). Most of these methods rely on at least 1 measure from a blood sample for scaling of the IDIF.Hence, blood sampling is not entirely obviated.
To our knowledge, there is currently no gold standard to define the real-time 18F-FDG arterial IF in mice in a reliable and easily accessible manner. In this study, we adapted a method for direct blood radioactivity measurements and an approach for the generation of IDIFs for use in mice. We acquired real-time blood radioactivity curves by means of a new coincidence counter in combination with an arteriovenous shunt and compared the findings to IDIFs generated from PET data of the cardiac region with an ensemblelearning independent component analysis (EL-ICA) algorithm (13).We used 2 different mouse strains to explore the possible strain dependency of our methods: C57BL/6 mice, because they are relevant for studies of genetically modified animals, and CD1 mice, because they are valuable as disease models,such as cerebral ischemia (14). The purpose of this work was 2-fold. First, we evaluated whether the arteriovenous-shunt/ counter technique, which was previously demonstrated in rats (15), is also feasible in mice. Second, we compared 18F-FDG kinetic parameters and fit precisions obtained with the experimental shunt IF and the IDIF.