Evaluation of transmission methodology and attenuation correction for the microPET Focus 220 animal scanner
Evaluation of transmission methodology and attenuation correction for the microPET Focus 220 animal scanner
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DOI：
10.1088/0031-9155/51/16/008
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发表时间：
2006-08-21
影响因子：
3.5
通讯作者：
Rosenfeld, Anatoly B.
中科院分区：
文献类型：
--
作者：
Lehnert, Wencke;Meikle, Steven R.;Rosenfeld, Anatoly B.
体内分子示踪剂分布的定量microPET研究需要受试者中光子衰减的准确、低噪声估计。在这项工作中，几个传输为基础的测量技术进行了比较，包括符合模式与和没有棒开窗，单一模式与两种不同的能源（Ge-68和Co-57），和后注入透射扫描。此外，传输分割的有效性和传输偏差和噪声到发射图像的传播进行了检查。Co-57单粒子测量提供了最精确的衰减系数和上级信噪比，而Ge-68单粒子测量由于来自物体的散射而退化。Ge-68透射数据的散射校正提高了10 cm体模的准确性，但对小鼠体模过度校正。Co-57扫描也导致低偏差和噪音在注射后传输扫描的排放活动高达20 MBq。分割工作最可靠的传输数据与Co-57，但衰减系数和信噪比的准确性的微小改善可能无法证明其使用，特别是对小的主题。我们的结论是，钴-57单透射扫描是最合适的方法测量衰减校正的microPET焦点220动物扫描仪。
An accurate, low noise estimate of photon attenuation in the subject is required for quantitative microPET studies of molecular tracer distributions in vivo. In this work, several transmission-based measurement techniques were compared, including coincidence mode with and without rod windowing, singles mode with two different energy sources (Ge-68 and Co-57), and postinjection transmission scanning. In addition, the effectiveness of transmission segmentation and the propagation of transmission bias and noise into the emission images were examined. The Co-57 singles measurements provided the most accurate attenuation coefficients and superior signal-to-noise ratio, while Ge-68 singles measurements were degraded due to scattering from the object. Scatter correction of Ge-68 transmission data improved the accuracy for a 10 cm phantom but over-corrected for a mouse phantom. Co-57 scanning also resulted in low bias and noise in postinjection transmission scans for emission activities up to 20 MBq. Segmentation worked most reliably for transmission data acquired with Co-57 but the minor improvement in accuracy of attenuation coefficients and signal-to-noise may not justify its use, particularly for small subjects. We conclude that Co-57 singles transmission scanning is the most suitable method for measured attenuation correction on the microPET Focus 220 animal scanner.