Quantitative PET with positron emitters that emit prompt gamma rays
Quantitative PET with positron emitters that emit prompt gamma rays
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DOI：
10.1109/42.476109
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发表时间：
1995-12-01
影响因子：
10.6
通讯作者：
Nickles, RJ
中科院分区：
文献类型：
--
作者：
Martin, CC;Christian, BT;Nickles, RJ
这项工作的目的是确定使用发射瞬发γ射线的正电子发射同位素的可行性，以获得定量的正电子发射断层扫描（PET）数据，使用标准的PET仪器。瞬发伽马可能会通过以下方式污染PET数据：增加死区时间、将单个事件转换为无效符合事件，以及产生可能导致无效符合事件替换有效符合事件的多个符合事件。在这项工作中的测量是通过扫描点源包含F-18，Na-22，和Co-60和研究的PET数据上的即时伽玛的影响。我们发现，对于Na-22点源，在扫描器的整个有效体积中，湮灭光子符合率约为瞬发伽马湮灭光子符合率的25倍。在散射情况下，Na-22瞬发γ湮灭光子符合率比F-18散射符合率高1.3倍。瞬发γ的最显著影响是增加死时间;对于相同的源活性，Cu-60的死时间校正因子比N-13的校正因子高2.4倍。我们的结论是，在许多情况下，定量PET数据可以很容易地获得与同位素发射即时伽马射线，使用标准的PET 2-D仪器。然而，在某些情况下，例如3-D PET，瞬发伽马可能会严重污染PET数据。
The purpose of this work was to determine the feasibility of using positron emitting isotopes that emit prompt gammas to acquire quantitative positron emission tomography (PET) data using standard PET instrumentation. Prompt gammas can contaminate PET data by: increasing dead time, converting singles into invalid coincidences, and producing multiple coincidences which can lead to the replacement of valid coincidences by invalid coincidences. The measurements in this work were made by scanning point sources containing F-18, Na-22, and Co-60 and studying the effects of the prompt gammas on the PET data. We found that for the Na-22 point source, the annihilation photon coincidence rate was about 25 times the prompt gamma-annihilation photon coincidence rate in the entire active volume of the scanner. With scatter, the Na-22 prompt gamma-annihilation photon coincidence rate was 1.3 times higher than the F-18 scatter coincidence rate. The most significant effect of the prompt gamma was to increase dead time; the dead time correction factor for Cu-60 was 2.4 times higher than the correction factor for N-13 for the same source activity. We conclude that, in many cases, quantitative PET data can be readily obtained with isotopes that emit prompt gammas, using standard PET 2-D instrumentation. However there are some cases, such as 3-D PET, where prompt gammas could significantly contaminate the PET data.