GEANT4 simulation of NSECT for detection of iron overload in the liver
GEANT4 simulation of NSECT for detection of iron overload in the liver
复制标题
GEANT4模拟NSECT检测肝脏铁过载
DOI：
10.1117/12.773245
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发表时间：
2008
影响因子：
3.2
通讯作者：
G. Tourassi
中科院分区：
文献类型：
--
作者：
A. Kapadia;B. Harrawood;G. Tourassi
中子受激发射计算机断层扫描（NSECT）被提议作为一种非侵入性技术来诊断人类铁过载。它利用入射中子和铁原子核之间的非弹性散射相互作用来刺激铁的伽马射线发射。对发射的伽马射线进行断层扫描检测可以得到有关肝脏中铁的浓度和空间分布的信息。早期的概念验证实验表明，NSECT 有潜力通过单位置光谱来量化肝脏铁过载的临床量。然而，用于患者诊断的断层扫描应用从未经过测试。这项工作使用断层扫描 NSECT 系统的蒙特卡罗模拟来研究通过断层扫描对肝脏铁的空间分布进行成像的可行性。在 GEANT4 中设计了 NSECT 系统的模拟，并用于对具有高浓度铁病变的模拟人类肝脏模型进行断层扫描。使用 MLEM 算法重建图像，并分析铁区域内的像素值，以确定检测的统计显着性。分析结果表明，在对应于0.72 mSv辐射剂量的中子暴露下，可以在周围肝组织中检测到3 mg/g的湿铁浓度，p值≤0.0001。这里进行的研究表明，NSECT 能够通过断层扫描对临床相关的铁分布进行成像。
Neutron stimulated emission computed tomography (NSECT) is being proposed as a non-invasive technique to diagnose iron overload in humans. It uses inelastic scatter interactions between incident neutrons and iron nuclei to stimulate gamma-ray emission from iron. Tomographic detection of the emitted gamma-rays yields information about the concentration and spatial distribution of iron in the liver. Early proof-of-concept experiments have shown that NSECT has the potential to quantify clinical quantities of liver iron overload through single-position spectroscopy. However, a tomography application for patient diagnosis has never been tested. This work uses a Monte-Carlo simulation of a tomographic NSECT system to investigate the feasibility of imaging the spatial distribution of liver iron through tomography. A simulation of an NSECT system has been designed in GEANT4 and used to tomographically scan a simulated human liver phantom with high-concentration iron lesions. Images are reconstructed with the MLEM algorithm and analyzed for pixel values within iron regions to determine the statistical significance of detection. Analysis results indicate that a wet iron concentration of 3 mg/g can be detected in surrounding liver tissue with p-value ≤ 0.0001 for neutron exposure corresponding to a radiation dose of 0.72 mSv. The research performed here demonstrates that NSECT has the ability to image clinically relevant distributions of iron through tomographic scanning.