Wenzel A
Department of Oral Radiology, Royal Dental College, Faculty of Health Sciences, University of Aarhus, Denmark.
Int Dent J. 1993 Apr;43(2):99-108.
In conventional film radiography, image quality is determined once the film has left the processing solutions. Conversely, in digital imaging, image quality may be interactively manipulated after image acquisition. Each of the parameters which define image quality: contrast, blur and noise, may be altered digitally. Filtering of the digital image may result in a reduction of blur of structure boundaries. Studies have shown that digital contrast enhancement and filtering increased diagnostic accuracy for the detection of caries lesions and for the estimation of lesion depth. Digital subtraction reduces anatomic image noise and has been demonstrated to aid the detection of differences in two images taken with a time interval. The technique has been demonstrated as being particularly useful for the detection of small tissue changes in marginal alveolar bone. The era of digital imaging in dentistry has certainly commenced and current intraoral digital systems have been shown to provide definite diagnostic advantages. Further, the direct digital systems rationalise the radiographic routine due to avoiding film and wet processing and conserve the environment. The major advantages may, however, be the significant dose reductions and the ability for image quality manipulation.
在传统的胶片放射摄影中，一旦胶片离开冲洗液，图像质量就已确定。相反，在数字成像中，图像质量在采集后可以进行交互式处理。定义图像质量的每个参数：对比度、模糊度和噪声，都可以进行数字更改。对数字图像进行滤波可能会减少结构边界的模糊度。研究表明，数字对比度增强和滤波提高了龋齿病变检测和病变深度估计的诊断准确性。数字减影可降低解剖图像噪声，并已被证明有助于检测在不同时间拍摄的两张图像之间的差异。该技术已被证明对检测边缘牙槽骨的微小组织变化特别有用。牙科数字成像时代无疑已经开始，目前的口腔内数字系统已被证明具有明确的诊断优势。此外，直接数字系统由于避免了胶片和湿法处理，使放射检查流程更加合理，还能保护环境。然而，主要优势可能是显著降低剂量以及能够对图像质量进行处理。
