Reyad Yasser A, Berbar Mohamed A, Hussain Muhammad
Department of Computer Science, College of Computer and Information Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia,
J Med Syst. 2014 Sep;38(9):100. doi: 10.1007/s10916-014-0100-7. Epub 2014 Jul 19.
Millions of women are suffering from breast cancer, which can be treated effectively if it is detected early. Mammography is broadly recognized as an effective imaging modality for the early detection of breast cancer. Computer-aided diagnosis (CAD) systems are very helpful for radiologists in detecting and diagnosing abnormalities earlier and faster than traditional screening programs. An important step of a CAD system is feature extraction. This research gives a comprehensive study of the effects of different features to be used in a CAD system for the classification of masses. The features are extracted using local binary pattern (LBP), which is a texture descriptor, statistical measures, and multi-resolution frameworks. Statistical and LBP features are extracted from each region of interest (ROI), taken from mammogram images, after dividing it into N×N blocks. The multi-resolution features are based on discrete wavelet transform (DWT) and contourlet transform (CT). In multi-resolution analysis, ROIs are decomposed into low sub-band and high sub-bands at different resolution levels and the coefficients of the low sub-band at the last level are taken as features. Support vector machines (SVM) is used for classification. The evaluation is performed using Digital Database for Screening Mammography (DDSM) database. An accuracy of 98.43 is obtained using statistical or LBP features but when both these types of features are fused, the accuracy is increased to 98.63. The CT features achieved classification accuracy of 98.43 whereas the accuracy resulted from DWT features is 96.93. The statistical analysis and ROC curves show that methods based on LBP, statistical measures and CT performs equally well and they not only outperform DWT based method but also other existing methods.
数以百万计的女性患有乳腺癌,如果能早期发现,乳腺癌是可以得到有效治疗的。乳房X线摄影术被广泛认为是早期检测乳腺癌的一种有效成像方式。计算机辅助诊断(CAD)系统对放射科医生非常有帮助,它能比传统筛查程序更早、更快地检测和诊断异常情况。CAD系统的一个重要步骤是特征提取。本研究全面探讨了在用于肿块分类的CAD系统中使用不同特征的效果。这些特征是使用局部二值模式(LBP,一种纹理描述符)、统计量和多分辨率框架提取的。在将乳房X光图像划分为N×N块后,从每个感兴趣区域(ROI)提取统计特征和LBP特征。多分辨率特征基于离散小波变换(DWT)和轮廓波变换(CT)。在多分辨率分析中,ROI在不同分辨率级别分解为低子带和高子带,最后一级低子带的系数被用作特征。支持向量机(SVM)用于分类。使用数字乳腺筛查数据库(DDSM)进行评估。使用统计特征或LBP特征时准确率为98.43,但当这两种类型的特征融合时,准确率提高到98.63。CT特征的分类准确率为98.43,而DWT特征的准确率为96.93。统计分析和ROC曲线表明,基于LBP、统计量和CT的方法表现同样出色,它们不仅优于基于DWT的方法,也优于其他现有方法。