Takeyama E, Yamamoto M, Kadowaki H, Imanaga H, Jimbo M
No Shinkei Geka. 1975 Jun;3(6):485-94.
It is well known that the gamma ray emitted by a radionuclide is a Poisson process, so its statistic nature should be taken in consideration when the scintiscanning is performed. But very few attempts have been done from this point of view. After examining in detail the imaging pulse charactristics, the authors introduced a mean for evaluating the fidelity of the collected data, and based on this criterion, pointed out some problems in the conventional scanning method and finally described a statistical way of improving the scintigram. In the present investigation, as a measure of the stochastic fidelity of the scanned data the relative deviation eplision(n) = sigma(n)/E(n) is introduced; sigma is the standard deviation and E(n) is the expectation value of the counting rate. In the conventional scanning in which the detector moves with a costant speed, the relative deviation varies from area to area according to the concentration of the radioisotope in the brain. In the so-called cold area of the brain scintigram, the relative deviation fluctuates remarkably because of a rather low density of radioisotope in this area.
众所周知，放射性核素发射的伽马射线是一个泊松过程，因此在进行闪烁扫描时应考虑其统计特性。但从这一角度进行的尝试很少。在详细研究成像脉冲特性之后，作者引入了一种评估采集数据保真度的方法，并基于此标准指出了传统扫描方法中的一些问题，最后描述了一种改进闪烁图的统计方法。在本研究中，引入相对偏差ε(n)=σ(n)/E(n)作为扫描数据随机保真度的度量；σ是标准差，E(n)是计数率的期望值。在探测器以恒定速度移动的传统扫描中，相对偏差会根据大脑中放射性同位素的浓度在不同区域有所变化。在脑闪烁图的所谓冷区，由于该区域放射性同位素密度相当低，相对偏差会显著波动。
