Finucane Ciara M, Murray Iain, Sosabowski Jane K, Foster Julie M, Mather Stephen J
Centre for Molecular Oncology and Imaging, Barts Cancer Institute, Queen Mary University of London, London EC1M 6BQ, UK.
Int J Mol Imaging. 2011;2011:197381. doi: 10.1155/2011/197381. Epub 2011 Mar 16.
We investigated the accuracy of a single photon emission computed tomography (SPECT) system in quantifying a wide range of radioactivity concentrations using different scan times in both phantom and animal models. A phantom containing various amounts of In-111 or Tc-99m was imaged until the activity had decayed close to background levels. Scans were acquired for different durations, employing different collimator pinhole sizes. VOI analysis was performed to quantify uptake in the images and the values compared to the true activity. The phantom results were then validated in tumour-bearing mice. The use of an appropriate calibration phantom and disabling of a background subtraction feature meant that absolute errors were within 12% of the true activity. Furthermore, a comparison of in vivo imaging and biodistribution studies in mice showed a correlation of 0.99 for activities over the 200 kBq to 5 MBq range. We conclude that the quantitative information provided by the NanoSPECT camera is accurate and allows replacement of dissection studies for assessment of radiotracer biodistribution in mouse models.
我们在体模和动物模型中，研究了单光子发射计算机断层扫描（SPECT）系统在使用不同扫描时间对广泛放射性浓度进行定量时的准确性。对含有不同量铟 - 111或锝 - 99m的体模进行成像，直至其放射性衰变至接近本底水平。采用不同的准直器针孔尺寸，对不同时长进行扫描。进行感兴趣区（VOI）分析以量化图像中的摄取量，并将所得值与真实活度进行比较。然后在荷瘤小鼠中验证体模实验结果。使用合适的校准体模并禁用背景扣除功能后，绝对误差在真实活度的12%以内。此外，对小鼠体内成像和生物分布研究的比较表明，在200 kBq至5 MBq范围内，活度的相关性为0.99。我们得出结论，NanoSPECT相机提供的定量信息准确，可替代解剖研究用于评估小鼠模型中放射性示踪剂的生物分布。
