Workman A, Brettle D S
Northern Ireland Medical Physics Agency, Forster Green Hospital, Belfast, UK.
Dentomaxillofac Radiol. 1997 May;26(3):139-46. doi: 10.1038/sj.dmfr.4600241.
New systems and technologies for dental radiographic imaging are being introduced at an increasing rate. Established methods of physical measurement allow the imaging performance of these systems to be quantified. These quantitative measures are important when comparing the imaging performance of competing systems. This review presents an overview of the main concepts in the assessment of the physical performance of imaging systems including signal transfer, as described by both the characteristic curve and modulation transfer function (MTF), and image noise, as described by the Noise Power Spectra. These measures can be combined to produce signal-to-noise ratio descriptors such as Noise Equivalent Quanta and Detective Quantum Efficiency which give an overall description of imaging system performance. Subjective means of measuring image quality, which naturally include the performance of the image display system and the observer, are also considered as a gauge of system performance.
牙科放射成像的新系统和技术正以越来越快的速度被引入。既定的物理测量方法能够对这些系统的成像性能进行量化。在比较竞争系统的成像性能时，这些定量测量很重要。本综述概述了成像系统物理性能评估中的主要概念，包括信号传递（由特性曲线和调制传递函数（MTF）描述）以及图像噪声（由噪声功率谱描述）。这些测量可以结合起来生成诸如噪声等效量子和探测量子效率等信噪比描述符，从而对成像系统性能进行全面描述。测量图像质量的主观方法，自然包括图像显示系统和观察者的性能，也被视为系统性能的一种衡量标准。
