University Hospitals of Leuven, Herestraat 49, Leuven, Brabant 3000, Belgium.
Med Phys. 2007 Jul;34(7):2744-58. doi: 10.1118/1.2742502.
This paper reports on a comparative study between the well-established test patterns for daily quality assurance (QA) of monitors of the American Association of Medical Physicists, Task Group 18 (AAPMtg18) and the Deutsches Institut für Normung e.V (DIN), and a newly proposed variable test pattern. A characteristic of the test patterns currently used for the QA of monitors is their static nature: The same test pattern is always used. This enables a learning effect that may bias the results over time. To address this problem we have developed a variable pattern for the quality assurance of monitors (MoniQA) that allows an evaluation of contrast visibility, geometric distortion, resolution, global image quality including uniformity, and artifacts. The test pattern includes randomly generated elements intended to prevent the observer from learning the test. Examples are random characters that have to be discriminated from the background to evaluate the threshold luminance difference and variable positions of different features in the test pattern. The newly proposed test patterns were generated and visualized on different viewing stations with a software tool developed in JAVA. In this study, we validated these patterns against the well-known AAPMtg18 and DIN test patterns on 22 monitors. The results showed that the MoniQA test can indicate the same monitor problems as the other well-known patterns and is significantly quicker to evaluate than the AAPMtg18 test patterns. The MoniQA pattern is a promising alternative for daily quality control of medical viewing stations.
本文报告了一项比较研究，比较了美国医学物理学家协会工作组 18（AAPMtg18）和德国标准化协会（DIN）用于监视器日常质量保证（QA）的成熟测试模式，以及新提出的可变测试模式。目前用于监视器 QA 的测试模式的一个特点是其静态性质：始终使用相同的测试模式。这使得随着时间的推移，学习效应可能会使结果产生偏差。为了解决这个问题，我们开发了一种用于监视器质量保证的可变模式（MoniQA），它可以评估对比度可见度、几何失真、分辨率、包括均匀性和伪影在内的全局图像质量。测试模式包括随机生成的元素，旨在防止观察者学习测试。例如，必须从背景中区分随机字符以评估阈值亮度差和测试模式中不同特征的可变位置，以此来评估随机字符。新提出的测试模式是使用在 JAVA 中开发的软件工具生成并在不同的查看站上可视化的。在这项研究中，我们在 22 个监视器上验证了这些模式与著名的 AAPMtg18 和 DIN 测试模式的有效性。结果表明，MoniQA 测试可以指示与其他知名模式相同的监视器问题，并且比 AAPMtg18 测试模式评估速度更快。MoniQA 模式是医疗查看站日常质量控制的一种很有前途的替代方案。
