Wagner Robert F, Brown David G
Office of Science and Technology, Center for Devices and Radiological Health, FDA, Rockville, MD 20857, USA.
Office of Device Evaluation, Center for Devices and Radiological Health, FDA, Rockville, MD 20857, USA.
Phys Med Biol. 1985 Jun;30(6):489-518. doi: 10.1088/0031-9155/30/6/001.
The ideal observer signal to noise ratio (snr) has been derived from statistical decision theory for all of the major medical imaging modalities. This snr provides an absolute scale for image system performance assessment and leads to instrumentation design goals and constraints for imaging system optimisation since no observer can surpass the performance of the ideal observer. The dependence of detectable detail size on exposure or imaging time follows immediately from the analysis. A framework emerges for comparing data acquisition techniques, e.g. reconstruction from projections versus Fourier methods in nmr imaging, and time of flight positron emission tomography (tofpet) versus conventional pet. The approach of studying the ideal observer is motivated by measurements on human observers which show that they can come close to the performance of the idea) observer, except when the image noise has negative correlations-as in images reconstructed from projections-where they suffer a small but significant penalty.
理想观察者信噪比（snr）已从统计决策理论推导得出，适用于所有主要的医学成像模态。这种信噪比为图像系统性能评估提供了一个绝对尺度，并导致了成像系统优化的仪器设计目标和约束条件，因为没有观察者能够超越理想观察者的性能。可检测细节尺寸对曝光或成像时间的依赖性可直接从分析中得出。由此出现了一个用于比较数据采集技术的框架，例如核磁共振成像中投影重建与傅里叶方法的比较，以及飞行时间正电子发射断层扫描（tofpet）与传统pet的比较。研究理想观察者的方法是由对人类观察者的测量所推动的，这些测量表明，除了图像噪声具有负相关性的情况（如从投影重建的图像），在这种情况下他们会受到小但显著的惩罚外，人类观察者能够接近理想观察者的性能。
