Comparison of software and human observers in reading images of the CDMAM test object to assess digital mammography systems
Comparison of software and human observers in reading images of the CDMAM test object to assess digital mammography systems
复制标题
软件和人类观察者在读取 CDMAM 测试对象图像以评估数字乳腺 X 线摄影系统方面的比较
DOI：
10.1117/12.653296
复制
发表时间：
2006
影响因子：
1.8
通讯作者：
H. Bosmans
中科院分区：
文献类型：
--
作者：
K. Young;J. Cook;J. Oduko;H. Bosmans
欧洲数字乳房x线照相术质量控制指南在阈值对比度方面规定了最低和可实现的图像质量标准，该标准基于人类观察者对CDMAM测试对象的图像的读数。然而，这是耗时的，并有很大的观察者间误差。为了克服这些问题，有一个软件程序（CDCOM）可以自动读取CDMAM图像，但没有定义解释输出的最佳方法。本研究评估了从程序中确定阈值对比度的方法，并将这些方法与各种乳房x光检查系统的人类读数进行了比较。考虑的方法是(A)简单阈值法(B)心理测量曲线拟合(C)平滑和插值(D)平滑和心理测量曲线拟合。每种方法的阈值对比相似，但再现性不同。方法(A)重复性较差，阈值对比标准误差为18.1±0.7%。通过使用对比细节曲线拟合程序，这一比例降至8.4%。方法(D)重现性最佳，误差为6.7%，曲线拟合后误差降至5.1%。一个由3人组成的小组通过曲线拟合将4.4%的误差降低到2.9%。所有自动方法得出的阈值对比都低于人类。人与程序阈值对比的比值随细节直径的变化而变化，为1.50±。04 （sem）在0.1mm和1.82±。方法(D)的0.25mm处的06。人工确定的阈值对比与自动化方法之间存在良好的相关性。
European Guidelines for quality control in digital mammography specify minimum and achievable standards of image quality in terms of threshold contrast, based on readings of images of the CDMAM test object by human observers. However this is time-consuming and has large inter-observer error. To overcome these problems a software program (CDCOM) is available to automatically read CDMAM images, but the optimal method of interpreting the output is not defined. This study evaluates methods of determining threshold contrast from the program, and compares these to human readings for a variety of mammography systems. The methods considered are (A) simple thresholding (B) psychometric curve fitting (C) smoothing and interpolation and (D) smoothing and psychometric curve fitting. Each method leads to similar threshold contrasts but with different reproducibility. Method (A) had relatively poor reproducibility with a standard error in threshold contrast of 18.1 ± 0.7%. This was reduced to 8.4% by using a contrast-detail curve fitting procedure. Method (D) had the best reproducibility with an error of 6.7%, reducing to 5.1% with curve fitting. A panel of 3 human observers had an error of 4.4% reduced to 2.9 % by curve fitting. All automatic methods led to threshold contrasts that were lower than for humans. The ratio of human to program threshold contrasts varied with detail diameter and was 1.50 ± .04 (sem) at 0.1mm and 1.82 ± .06 at 0.25mm for method (D). There were good correlations between the threshold contrast determined by humans and the automated methods.