Center for Statistical Consultation and Research, University of Michigan, Ann Arbor, MI, USA.
Acad Radiol. 2010 Apr;17(4):511-9. doi: 10.1016/j.acra.2009.12.003.
The International Labour Office (ILO) system for classifying chest radiographic changes related to inhalation of pathogenic dusts is predicated on film-screen radiography. Digital radiography has replaced film in many centers. Digital images can be printed on film ("hard copy") or can be viewed at a computer workstation ("soft copy"). The goal of the present investigation was to compare the inter-reader and intra-reader agreement of ILO classifications for pneumoconiosis across image formats.
Traditional film radiographs, hard copy digital images, and soft copy digital images from 107 subjects were read by six B readers. A multiple reader version of the inter-reader kappa statistic was compared across image formats. Intra-reader kappa comparisons were carried out using an iterative least-squares approach (unadjusted analysis) as well as a two-stage regression model adjusting for readers and subject-level covariates.
There were few significant differences in the inter-reader and intra-reader agreement across formats. For parenchymal abnormalities, inter-reader and intra-reader kappa values ranged from 0.536 to 0.646, and 0.65 to 0.77, respectively. In the covariate-adjusted analysis film-screen radiography was generally associated with a numerically greater reliability (ie, higher kappa values) than the other image formats, although differences were rarely statistically significant.
Film-screen radiographs, hard copy digital images, and soft copy digital images yielded similar reliability measures. These findings provide further support to the recommendation that soft copy digital images can be used for the recognition and classification of dust-related parenchymal abnormalities using the ILO system.
国际劳工组织（ILO）用于分类与吸入致病性粉尘有关的胸部 X 射线改变的系统基于胶片射线照相。数字射线照相术已在许多中心取代了胶片。数字图像可以打印在胶片上（“硬拷贝”），也可以在计算机工作站上查看（“软拷贝”）。本研究的目的是比较不同图像格式的 ILO 尘肺分类的读者间和读者内一致性。
对 107 名受试者的传统胶片射线照片、硬拷贝数字图像和软拷贝数字图像进行了六位 B 读者的阅读。比较了跨图像格式的读者间κ统计量的多重读者版本。使用迭代最小二乘法（未调整分析）以及调整读者和受试者水平协变量的两阶段回归模型进行了读者内κ比较。
在不同格式之间，读者间和读者内的一致性差异很小。对于实质异常，读者间和读者内的κ值范围分别为 0.536 至 0.646 和 0.65 至 0.77。在协变量调整分析中，与其他图像格式相比，胶片射线照相通常与数字可靠性（即更高的κ值）相关，尽管差异很少具有统计学意义。
胶片射线照相、硬拷贝数字图像和软拷贝数字图像产生了相似的可靠性测量值。这些发现进一步支持了使用 ILO 系统识别和分类与粉尘相关的实质异常时可以使用软拷贝数字图像的建议。
