[Application of multiple empirical kernel mapping ensemble classifier based on self-paced learning in ultrasound-based computer-aided diagnosis for breast cancer]

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2021 Feb 25;38(1):30-38. doi: 10.7507/1001-5515.202002004.
[Article in Chinese]

Abstract

Both feature representation and classifier performance are important factors that determine the performance of computer-aided diagnosis (CAD) systems. In order to improve the performance of ultrasound-based CAD for breast cancers, a novel multiple empirical kernel mapping (MEKM) exclusivity regularized machine (ERM) ensemble classifier algorithm based on self-paced learning (SPL) is proposed, which simultaneously promotes the performance of both feature representation and the classifier. The proposed algorithm first generates multiple groups of features by MEKM to enhance the ability of feature representation, which also work as the kernel transform in multiple support vector machines embedded in ERM. The SPL strategy is then adopted to adaptively select samples from easy to hard so as to gradually train the ERM classifier model with improved performance. This algorithm is verified on a B-mode ultrasound dataset and an elastography ultrasound dataset, respectively. The results show that the classification accuracy, sensitivity and specificity on B-mode ultrasound are (86.36±6.45)%, (88.15±7.12)%, and (84.52±9.38)%, respectively, and the classification accuracy, sensitivity and specificity on elastography ultrasound are (85.97±3.75)%, (85.93±6.09)%, and (86.03±5.88)%, respectively. It indicates that the proposed algorithm can effectively improve the performance of ultrasound-based CAD for breast cancers with the potential for application.

特征表达和分类器的性能是决定计算机辅助诊断(CAD)系统性能的重要因素。为了提升基于超声成像的乳腺癌 CAD 系统的性能,本文提出了一种基于自步学习(SPL)的多经验核映射(MEKM)排他性正则化机(ERM)集成分类器算法,能同时提升特征表达和分类器模型的性能。该算法首先通过 MEKM 映射得到多组特征,以增强特征表达能力,并嵌入到 ERM 作为多个支持向量机的核变换;然后采用 SPL 策略自适应地选择样本,由易到难地逐步训练 ERM 集成分类器模型,从而提升分类器的性能。该算法分别在乳腺癌 B 型超声数据库和弹性超声数据库上进行了验证,结果显示 B 型超声的分类准确率、敏感度和特异性分别为 (86.36±6.45)%、(88.15±7.12)% 和 (84.52±9.38)%,而弹性超声的分类准确率、敏感度和特异性分别为 (85.97±3.75)%、(85.93±6.09)% 和 (86.03±5.88)%。实验结果表明,本文所提出算法能有效提升乳腺超声 CAD 的性能,具有投入实用的潜能。.

Keywords: breast cancer; ensemble learning; exclusivity regularized machine; multiple empirical kernel mapping; self-paced learning; ultrasound imaging.

MeSH terms

  • Algorithms
  • Breast Neoplasms* / diagnostic imaging
  • Computers
  • Diagnosis, Computer-Assisted
  • Humans
  • Support Vector Machine
  • Ultrasonography

Grants and funding

国家自然科学基金项目(81627804,81830058);上海市科委项目(17411953400,18010500600,18411967400)