Development of advanced CAD system for mammography and its practical application

本研究的目的是开发一个改进的乳腺X线摄影CAD系统，并提高系统的性能。主要结果如下。[1]系统对成像条件的变化具有鲁棒性在日本的五个医疗机构安装了传统的CAD系统，并对其性能进行了测试。每个医疗机构都有自己的成像条件，传统系统的性能取决于它们。我们开发了新的处理算法，使CAD系统对成像条件的变化不敏感。[2]改进的肿瘤检测方法自适应环形滤波器已经开发出来，这使得检测具有粗糙和不规则密度分布的肿瘤成为可能。自适应环形滤波器的性能已被证明是优于虹膜滤波器的性能的上级。[3]靠近或附着于胸壁的肿瘤的检测靠近或附着于胸壁的肿瘤容易被传统的CAD系统遗漏。对它们的检测算法进行了修改。也就是说，在胸壁附近的区域中的候选者通过由本项目开发的不同算法来识别。新系统的性能已变得比传统系统更高。[4]先进的微钙化检测方法粗钙化导致假微钙化。我们提出了一种新的粗钙化点检测方法，它可以帮助减少错误的微钙化点簇。复杂的背景可引起假性微钙化。我们还开发了一种算法来排除它们，这些方法已经安装在新的CAD系统中。

The purpose of this research project is to develop an improved CAD system for mammography and to heighten the system performance. The main results are as follows.[1]System robust to variations of imaging conditionThe conventional CAD system has been installed is five medical institutions in Japan and its performance had been tested . Each medical institution has its own imaging conditions and the performance of the conventional system depends on them. We have developed new processing algorithm, which makes the CAD system insensitive to the variation of imaging conditions.[2]Revised tumor detection methodAdaptive ring filter has been developed, which makes it possible to detect tumors with rough and irregular density distributions. The performance of the adaptive ring filter has been shown to be superior to that of the iris filter.[3]Detection of tumors close to or attached to thoracic wallTumors close to or attached to thoracic wall tend to be missed by the conventional CAD system. The detection algorithm for them has been revised. That is, the candidates in the area near thoracic wall are recognized by the different algorithm developed by this project. The performance of the new system has become higher than that of the conventional system.[4]Advanced microcalcification detection methodCoarse-calcification causes false microcalcifications. We have developed a new method for coarse-calcification detection, which can help decreasing false microcalcification clusters. Complicated background can cause false microcalcifications. We have also developed an algorithm to exclude them.These methods described above have been installed in the new CAD system.