A test pattern for quality control of laser scanner and charge-coupled device film digitizers

Although clinical images provide the ultimate test of diagnostic performance for a film digitizer, such images are not generally suitable for daily quality control (QC) purposes. However, a well-designed test pattern will provide a rapid, comprehensive, objective and reproducible assessment of image quality. This pattern should evaluate various parameters of image quality, including high contrast resolution, low contrast discrimination, linearity of gray scale, geometric distortion, and noise. Furthermore, the pattern should detect light leak and film slippage, two problems commonly associated with film digitizers. The test pattern described in this manuscript was designed to provide quantitative measures of performance for a film digitizer. As part of a regular QC routine for a laser scanner or charge-coupled device digitizer, this pattern provides a simple method to identify and quantify changes in digital image quality.