Application of multiple empirical kernel mapping ensemble classifier based on self-paced learning in ultrasound-based computer-aided diagnosis for breast cancer / 生物医学工程学杂志

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.

A study of high frame rate ultrasonic imaging with limited diffraction beams / 西安交通大学学报·英文版

Objective: To investigate a new class of solutions to the isotropic/homogeneous scalar wave equation, which termed limited diffraction beams and realize ultrasonic 3D imaging. Methods: Limited diffraction beams were derived. We performed the study of 3D pulse-echo imaging with limited diffraction array beam. To obtain high frame rate images, a single plane wave pulse (broadband) was transmitted with the arrays. Echoes received with the same arrays were processed with Fourier method to construct 3D images. Results: Compared with traditional pulse-echo imaging, this method has a larger depth of field, high frame rate, and high signal-to-noise ratio. Conclusion: The new method has prospect of high frame rate 3D imaging. In addition, the imaging system based this method is easily implemented and has high quality image.