title: Strain estimation in elastography using scale-invariant keypoints tracking.
abstract: This paper proposes a novel strain estimator using scale-invariant keypoints tracking (SIKT) for ultrasonic elastography. This method is based on tracking stable features between the pre- and post-compression A-lines to obtain tissue displacement estimates. The proposed features, termed scaleinvariant keypoints, are independent of signal scale change according to the scale-space theory, and therefore can preserve their patterns while undergoing a substantial range of compression. The keypoints can be produced by searching for repeatedly assigned points across all possible scales constructed from the convolution with a one-parameter family of Gaussian kernels. Because of the distinctive property of the keypoints, the SIKT method could provide a reliable tracking over changing strains, an effective resistance to anamorphic noise and sonographic noise, and a significant reduction in processing time. Simulation and experimental results show that the SIKT method is able to provide better sensitivity, a larger dynamic range of the strain filter, higher resolution, and a better contrast- to-noise ratio (CNRe) than the conventional methods. Moreover, the computation time of the SIKT method is approximately 5 times that of the cross-correlation techniques.
authors.affiliation: Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xiao
authors.forename: Yang
authors.initials: Y
authors.lastname: Shen
authors.forename: Lili
authors.initials: L
authors.lastname: Niu
authors.forename: Tao
authors.initials: T
authors.lastname: Ling
authors.forename: Congzhi
authors.initials: C
authors.lastname: Wang
authors.forename: Hairong
authors.initials: H
authors.lastname: Zheng
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D054459:Elasticity Imaging Techniques / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio; D013314:Stress, Mechanical