Zaidi Habib, Koral Kenneth F
Division of Nuclear Medicine, Geneva University Hospital, 1211 Geneva, Switzerland.
Eur J Nucl Med Mol Imaging. 2004 May;31(5):761-82. doi: 10.1007/s00259-004-1495-z. Epub 2004 Mar 31.
In nuclear medicine, clinical assessment and diagnosis are generally based on qualitative assessment of the distribution pattern of radiotracers used. In addition, emission tomography (SPECT and PET) imaging methods offer the possibility of quantitative assessment of tracer concentration in vivo to quantify relevant parameters in clinical and research settings, provided accurate correction for the physical degrading factors (e.g. attenuation, scatter, partial volume effects) hampering their quantitative accuracy are applied. This review addresses the problem of Compton scattering as the dominant photon interaction phenomenon in emission tomography and discusses its impact on both the quality of reconstructed clinical images and the accuracy of quantitative analysis. After a general introduction, there is a section in which scatter modelling in uniform and non-uniform media is described in detail. This is followed by an overview of scatter compensation techniques and evaluation strategies used for the assessment of these correction methods. In the process, emphasis is placed on the clinical impact of image degradation due to Compton scattering. This, in turn, stresses the need for implementation of more accurate algorithms in software supplied by scanner manufacturers, although the choice of a general-purpose algorithm or algorithms may be difficult.
在核医学中，临床评估和诊断通常基于对所使用放射性示踪剂分布模式的定性评估。此外，发射断层扫描（单光子发射计算机断层扫描和正电子发射断层扫描）成像方法提供了在体内对示踪剂浓度进行定量评估的可能性，以便在临床和研究环境中对相关参数进行量化，前提是要对妨碍其定量准确性的物理衰减因素（例如衰减、散射、部分容积效应）进行准确校正。本综述探讨了康普顿散射这一发射断层扫描中主要的光子相互作用现象所带来的问题，并讨论了其对重建临床图像质量和定量分析准确性的影响。在进行总体介绍之后，有一部分详细描述了均匀和非均匀介质中的散射建模。接下来是对用于评估这些校正方法的散射补偿技术和评估策略的概述。在此过程中，重点在于康普顿散射导致的图像退化的临床影响。这反过来强调了扫描仪制造商所提供软件中实施更精确算法的必要性，尽管选择通用算法可能会很困难。
