[18F]Fallypride dopamine D2 receptor studies using delayed microPET scans and a modified Logan plot
[18F]Fallypride dopamine D2 receptor studies using delayed microPET scans and a modified Logan plot
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DOI：
10.1016/j.nucmedbio.2009.06.007
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发表时间：
2009-11-01
影响因子：
3.1
通讯作者：
Peterson, Todd E.
中科院分区：
文献类型：
--
作者：
Tantawy, Mohammed N.;Jones, Carrie K.;Peterson, Todd E.
[F-18]Fallypride PET研究可用于估计大脑多巴胺D2/D3受体富集区域的体内不可替代结合电位（BPND）。这些研究通常需要相当长的时间，长达>= 2小时，限制了吞吐量。在这项工作中，我们研究了在示踪剂施用之后进行的有限持续时间扫描是否产生稳定的BPND估计。特别地，我们应用了修改版本的文件Logan图方法油的最后60分钟的120分钟的数据，并将结果与来自全数据集的分析的结果进行比较。14只雄性Sprague-Dawley大鼠在异氟烷麻醉下静脉注射[F-18]fallypride，在microPET Focus 220扫描仪上采集动态数据120分钟。（DVR=BPND+1）计算从洛根图使用120分钟的数据，并从修改后的版本，仅使用最后60分钟。这些大鼠中的三个再次成像油第二天，以测试再现性。还使用双组织室模型拟合120 min扫描的时间-活性曲线（TAC），以估计参数K-1、k（2）、k（on）、k（4）和B-max。然后，这些参数用于模拟类似的TAC，同时改变k（on）以反映多巴胺能系统的变化。模拟的TAC用作探索仅最后60分钟和完整120分钟模拟数据之间DVR估计差异的方法。结果：完整120分钟扫描的平均DVR为13.8 +/- 0.9，而仅根据最后60分钟数据估计的文件平均DVR（DVR '）为16.3 +/- 1.0。DVR估计值在三只大鼠中显示出良好的再现性（第1天平均DVR=13.8 +/- 1.5，第2天DVR=13.8 +/- 0.9）。仿真结果表明，DVR'和DVR估计之间的关系遵循它的半线性形式与变化的k（上）。结论：虽然BPND估计略有高估在延迟扫描模式（即，无初始放射性示踪剂摄取测量）相比，这种高估主要取决于k（3）（近似于k（on）x B-max），并且在这项工作中已经使用模拟TAC针对宽范围的k（on）值进行了评估。特别地，DVR'对k（on）的变化的灵敏度类似于DVR。这种延迟扫描的方法消除了在放射性示踪剂的初始摄取期间成像的必要性，并且因此可以用于增加研究的吞吐量。(C)2009 Elsevier Inc. All rights reserved.
[F-18]Fallypride PET studies can be used to estimate the nondisplaceable binding potential (BPND) in vivo of dopamine D2/D3 receptor-rich regions of the brain. These Studies often take considerable time, up to >= 2 h, limiting the throughput. in this work, we investigated whether limited-duration scans performed Subsequent to tracer administration yielded stable BPND estimates. In particular, we applied a modified version of file Logan plot method oil the last 60 min of 120-min data and compared the results to those from analysis of the full data set.Methods: Fourteen male Sprague-Dawley rats were injected with [F-18]fallypride intravenously while under isoflurane anesthesia, and dynamic data were acquired on the microPET Focus 220 scanner for 120 min. The distribution Volume ratio (DVR=BPND+1) was calculated from a Logan plot using 120 min of data and from a modified version using only the last 60 min. Three of these rats were imaged again oil a second day to test the reproducibility. A two-tissue compartment model also was used to fit the time-activity Curves (TACs) of the 120-min scans to estimate the parameters K-1, k(2), k(on), k(4) and B-max. These parameters were then used to simulate similar TACs while changing k(on) to reflect changes in the dopaminergic system. The simulated TACs were used as a means for exploring the differences in DVR estimates between the last 60 min only and the full 120 min of simulated data.Results: The average DVR from the full 120-min scans was 13.8 +/- 0.9, whereas file average DVR estimated from only the last 60 min of data (DVR') was 16.3 +/- 1.0. The DVR estimates showed good reproducibility in the three rats (mean DVR=13.8 +/- 1.5 on Day 1 and DVR=13.8 +/- 0.9 on Day 2). The simulations showed that the relationship between DVR' and DVR estimates follows it semilinear form with varying k(on).Conclusion: Although the BPND estimates are slightly overestimated in a delayed scan mode (i.e., no initial radiotracer uptake measurements) compared to a full scan, this overestimation depends primarily on k(3) (approximate to k(on) x B-max) and has been evaluated in this work for a wide range of k(on) values using simulated TACs. In particular, the sensitivity of DVR' to changes in k(on) is similar to that of DVR. This method of delayed scans eliminates the necessity of imaging during the initial uptake of the radiotracer and, thus, can be used to increase the throughput Of Studies. (C) 2009 Elsevier Inc. All rights reserved.