Slifstein M, Laruelle M
Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
Nucl Med Biol. 2001 Jul;28(5):595-608. doi: 10.1016/s0969-8051(01)00214-1.
The science of quantitative analysis of PET and SPECT neuroreceptor imaging studies has grown considerably over the past decade. A number of methods have been proposed in which receptor parameter estimation results from fitting data to a model of the underlying kinetics of ligand uptake in the brain. These approaches have come to be collectively known as model-based methods and several have received widespread use. Here, we briefly review the most frequently used methods and examine their strengths and weaknesses. Kinetic modeling is the most direct implementation of the compartment models, but with some tracers accurate input function measurement and good compartment configuration identification can be difficult to obtain. Other methods were designed to overcome some particular vulnerability to error of classical kinetic modeling, but introduced new vulnerabilities in the process. Reference region methods obviate the need for arterial plasma measurement, but are not as robust to violations of the underlying modeling assumptions as methods using the arterial input function. Graphical methods give estimates of V(T) without the requirement of compartment model specification, but provide a biased estimator in the presence of statistical noise. True equilibrium methods are quite robust, but their use is limited to experiments with tracers that are suitable for constant infusion. In conclusion, there is no universally "best" method that is applicable to all neuroreceptor imaging studies, and carefully evaluation of model-based methods is required for each radiotracer.
在过去十年中，PET和SPECT神经受体成像研究的定量分析科学有了显著发展。已经提出了许多方法，其中受体参数估计是通过将数据拟合到大脑中配体摄取的潜在动力学模型来实现的。这些方法统称为基于模型的方法，其中一些已得到广泛应用。在此，我们简要回顾最常用的方法，并考察它们的优缺点。动力学建模是房室模型最直接的实现方式，但对于一些示踪剂来说，准确测量输入函数和识别良好的房室配置可能很难实现。其他方法旨在克服经典动力学建模中某些特定的误差易感性，但在此过程中引入了新的易感性。参考区域法无需测量动脉血浆，但在违反潜在建模假设方面不如使用动脉输入函数的方法稳健。图形法无需指定房室模型即可给出V(T)的估计值，但在存在统计噪声时会提供有偏差的估计量。真正的平衡法相当稳健，但其应用仅限于使用适合恒速输注的示踪剂的实验。总之，没有一种普遍适用的“最佳”方法适用于所有神经受体成像研究，每种放射性示踪剂都需要仔细评估基于模型的方法。
