Busemann-Sokole E, Farrell T J, Cradduck T D
J Nucl Med. 1985 Nov;26(11):1323-30.
A rotating cardiac phantom with three possible ejection fraction (EF) values was used in conjunction with a scintillation camera employing energy correction and count skim arithmetic for uniformity correction. Studies were collected with and without any correction, with the energy window of the analyzer set properly, and with the camera properly tuned. The uniformity was then degraded in one experiment by off-setting the analyzer window both high and low with respect to the primary photopeak and in another experiment by de-tuning a selected photomultiplier tube. In both experiments studies were taken with no correction enabled, and then with each of the correction options enabled. The results of both experiments show that ejection fraction values could be in error when the differential uniformity using National Electrical Manufacturers Association (NEMA) protocols exceeds 10%. If either energy correction alone, or energy correction combined with count skim correction is used, the ejection fraction values return to more acceptable values. Asymmetric windows, improper setting of the energy window or a badly tuned photomultiplier will likely result in poor analog images before the effect on ejection fraction measurements becomes evident. Uniformity correction devices do not adversely affect the numerical results obtained from these phantom studies, but should, nevertheless, be used with caution.
使用了具有三种可能射血分数（EF）值的旋转心脏模型，并结合采用能量校正和计数剔除算法进行均匀性校正的闪烁相机。在分析仪能量窗口设置正确且相机调整适当的情况下，分别在有无任何校正的情况下收集研究数据。然后，在一个实验中，通过将分析仪窗口相对于主要光电峰上下偏移来降低均匀性，在另一个实验中，通过失调选定的光电倍增管来降低均匀性。在这两个实验中，均在未启用校正的情况下进行研究，然后在启用每种校正选项的情况下进行研究。两个实验的结果均表明，当使用美国国家电气制造商协会（NEMA）协议的差异均匀性超过10%时，射血分数值可能会出现误差。如果单独使用能量校正，或能量校正与计数剔除校正相结合，则射血分数值会恢复到更可接受的值。在对射血分数测量产生明显影响之前，不对称窗口、能量窗口设置不当或光电倍增管调整不当可能会导致模拟图像质量较差。均匀性校正装置不会对从这些模型研究中获得的数值结果产生不利影响，但仍应谨慎使用。
