Potential of a Compton camera for high performance scintimammography.
Potential of a Compton camera for high performance scintimammography.
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康普顿相机在高性能闪烁放射成像方面的潜力。
DOI：
10.1088/0031-9155/49/4/011
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发表时间：
2004
影响因子：
3.5
通讯作者：
Clinthorne,NealH
中科院分区：
文献类型：
--
作者：
Zhang,Lisha;Rogers,WLeslie;Clinthorne,NealH
在本文中，我们提出了一种基于康普顿相机原理的新方法。我们用蒙特卡罗模拟分析了我们的方案的性能。特别地，我们评估了该系统在几个伽马光子能量下的检测效率、空间分辨率和损伤可见性。仿真结果表明，该技术在5 cm厚的硅探测器胸片中，以141 keV光子能量对2.5 cm深的点源进行探测，绝对探测效率为0.03，全宽半最大分辨率为3.8 mm。此外，我们的方法在病变检测方面表现出良好的性能，特别是在高伽马光子能量的情况下，由于严重的间隔穿透，机械准直系统表现不佳。我们的系统总共收集了135万个计数，相当于在正常乳腺组织中3.7 kBq ml - 1 （100 nCi cm - 3）的活性浓度水平下30秒的采集时间，肿瘤与背景的比例为8:1，我们的系统可以清楚地显示位于500 ml乳腺幻影中2.5 cm深的直径为8 mm的肿瘤。我们还提出了基于模拟的定量性能比较，在临床成像情况下，使用非预白化匹配滤波器观察者模型，在病变检测任务中，所提出的ct扫描系统和紧凑型准直ct扫描系统。我们的比较表明，在相同的成像时间内，两种系统在141 keV下检测8毫米肿瘤方面具有相当的性能，其中所提出的系统性能略好。然而，提出的扫描系统明显优于紧凑型准直对应的5毫米肿瘤的检测。我们还研究了邻近器官的散射和直接辐射的贡献。我们发现，在141 keV时，肝脏对右乳房的背景贡献为30%，在屏蔽后可降至4.8%。
In this paper, we present a novel approach to scintimammography that is based on the Compton camera principle. We analyse the performance of our scheme using Monte Carlo simulations. In particular, we evaluate the detection efficiency, spatial resolution and lesion visibility of the system at several gamma photon energies. The simulation results show that the proposed technique achieves an absolute detection efficiency of 0.03 and a full width at half maximum resolution of 3.8 mm at 141 keV photon energy for point sources 2.5 cm deep in a 5 cm thick breast phantom using 5 mm thick silicon detectors. Furthermore, our approach shows good performance in lesion detection, especially at high gamma photon energies, where mechanically collimated systems perform poorly due to severe septal penetration. With total collected counts of 1.35 million, equivalent to a 30 s acquisition time for an activity concentration level of 3.7 kBq ml− 1 (100 nCi cm− 3) in normal breast tissue, and a tumour-to-background ratio of 8: 1, our system can clearly reveal an 8 mm diameter tumour that is located 2.5 cm deep in a 500 ml breast phantom. We also present a simulation-based quantitative performance comparison between the proposed scintimammographic system and the compact collimated scintimammographic system in the task of lesion detection under a clinical imaging situation using a non-prewhitening matched filter observer model. Our comparison demonstrates that for the same imaging time, the two systems have a comparable performance in detecting an 8 mm tumour at 141 keV, with the proposed system performing marginally better. However, the proposed scintimammographic system clearly outperforms the compact collimated counterpart in the detection of a 5 mm tumour. We also investigate the contribution of scatter and direct radiation from adjacent organs. We find that the background contribution of liver to the right breast is 30% at 141 keV, which can be reduced to 4.8% with shielding.