Gratt B M, Sickles E A
Oral Surg Oral Med Oral Pathol. 1983 Nov;56(5):555-9. doi: 10.1016/0030-4220(83)90109-3.
Dental xeroradiography is a high-quality intraoral imaging system which provides a potentially convenient, rapid, low-dose alternative to conventional film radiography. In this study the sensitometric properties of dental xeroradiography were investigated via assessment of high- and low-contrast xeroradiographic processor settings, transmission versus reflection densitometry, reciprocity-law failure, and kVp (tube voltage) plate dependence. Findings of the study indicated that imaging at high-contrast processor settings results in greater dynamic range but less exposure latitude than imaging at low-contrast processor settings. Determination of characteristic curves demonstrated greater contrast in reflection mode than imaging by transillumination for all but the very densest of images (greater than 1.6 O.D.). There was also little difference in characteristic curves produced from 50 to 90 kVp, indicating that the xeroradiographic plate exhibits a relatively constant sensitivity over the tube voltages tested if exposure is expressed in roentgens. Finally, no substantial reciprocity-law failure was observed for dental xeroradiography over a clinically relevant range of exposure times.
牙科干板X线摄影是一种高质量的口腔内成像系统,它为传统胶片X线摄影提供了一种潜在方便、快速、低剂量的替代方法。在本研究中,通过评估高对比度和低对比度干板X线摄影处理设置、透射与反射密度测定、互易律失效以及千伏峰值(管电压)对成像板的依赖性,研究了牙科干板X线摄影的感光特性。研究结果表明,与在低对比度处理设置下成像相比,在高对比度处理设置下成像可获得更大的动态范围,但曝光宽容度更小。特性曲线的测定表明,除了密度非常高(大于1.6光密度)的图像外,反射模式下的对比度高于透照成像。在50至90千伏峰值下产生的特性曲线也几乎没有差异,这表明如果以伦琴表示曝光量,在测试的管电压范围内,干板X线摄影成像板表现出相对恒定的灵敏度。最后,在临床相关的曝光时间范围内,未观察到牙科干板X线摄影存在明显的互易律失效。