Image artifacts at high photon fluence rates in single-crystal NaI(T1) scintillation cameras.
Image artifacts at high photon fluence rates in single-crystal NaI(T1) scintillation cameras.
复制标题
单晶 NaI(T1) 闪烁相机中高光子注量率下的图像伪影。
DOI：
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发表时间：
1978
影响因子：
9.3
通讯作者：
I. Larsson
中科院分区：
文献类型：
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作者：
S. Strand;I. Larsson
模拟临床相关情况的方法用于通过区分正确和不正确定位的事件来测量伽马图像中的脉冲堆积量。然后比较来自不同相机的响应。这些研究表明，堆积拒绝计数率的影响。对于某些相机，可以在大约10，000/秒的低计数率和30%的能量窗口下确定堆积效应。影响闪烁相机的总计数率的参数-如散射介质，源的几何形状，准直器，和能量窗口-进行了研究。结果表明，光子注量的能量分布决定了计数损失和图像失真，而不是能量窗口内的计数率。这里描述的方法可以满足比较闪烁相机的新方法的要求。重要的是要注意，没有散射介质的测量产生的结果与临床情况无关。
A method that simulates a clinically relevant situation is used to measure the amount of pulse pileup in the gamma image by distinguishing between correctly and incorrectly positioned events. Comparison was then made between responses from different cameras. These investigations show the influence of pileup rejection on counting rate. Pileup effects can be determined for some cameras at such low count rates as about 10,000/sec with a 30% energy window. Parameters affecting the total count rate of the scintillation camera--such as scattering media, source geometry, collimator, and energy window--have been investigated. It is shown that the energy distribution of the photon fluence striking the crystal determines the counting losses and image distortion, rather than the counting rate in the energy window. The approach described here might fulfill the requirements for a new method to compare scintillation cameras. It is important to note that measurements without scattering medium yield results irrelevant for clinical situations.