Casey M E, Hoffman E J
J Comput Assist Tomogr. 1986 Sep-Oct;10(5):845-50.
A method of processing accidental coincidence events (AC) and detector efficiency (DE) calibration data, which reduces the statistical noise in these measurements, and, consequently, reduces the noise in positron emission tomographic images using the technique, is described. The technique uses the fact that, in these measurements with N detectors in coincidence with N other detectors, N2 values of ACs or DEs are measured. However, these values are composed of only 2N components, which are either singles rates or individual DEs. The full set of data is used to implicitly solve for these values and the individual ACs or DEs recalculated with an improvement in statistical error equivalent to an N2/(2N + 1) increase in accumulated events for the case of a uniform distribution. This result was verified experimentally.
描述了一种处理偶然符合事件（AC）和探测器效率（DE）校准数据的方法，该方法可降低这些测量中的统计噪声，从而使用该技术降低正电子发射断层图像中的噪声。该技术利用了这样一个事实，即在这些测量中，N个探测器与另外N个探测器符合，会测量到N²个AC或DE值。然而，这些值仅由2N个分量组成，这些分量要么是单计数率，要么是单个DE。使用完整数据集隐式求解这些值，并重新计算各个AC或DE，对于均匀分布的情况，统计误差的改善相当于累积事件增加了N²/(2N + 1)。这一结果通过实验得到了验证。
