PHYSICAL PERFORMANCE-MEASURES OF RADIOGRAPHIC IMAGING-SYSTEMS

New systems and technologies for dental radiographic imaging are being introduced at an increasing rate. Established methods of physical mea surement allow the imaging performance of these systems to be quantifi ed. These quantitative measures are important when comparing the imagi ng 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 ch aracteristic curve and modulation transfer function (MTF), and image n oise, as described by the Noise Power Spectra. These measures can be c ombined to produce signal-to-noise ratio descriptors such as Noise Equ ivalent Quanta and Detective Quantum Efficiency which give an overall description of imaging system performance. Subjective means of measuri ng image quality, which naturally include the performance of the image display system and the observer, are also considered as a gauge of sy stem performance.