PAI-CHI LILee, W.-N.W.-N.Lee2020-04-162020-04-16200201617346https://scholars.lib.ntu.edu.tw/handle/123456789/484598https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036820781&doi=10.1177%2f016173460202400402&partnerID=40&md5=ad127697762b4acb4752012e6627404eAn efficient speckle tracking algorithm is proposed for motion estimation in ultrasonic imaging. Speckle tracking involves a matching process and a searching process. The matching process of the proposed algorithm is based on a Block Sum Pyramid algorithm that significantly reduces the computational complexity while maintaining the same accuracy as the conventional sum of absolute difference approach. The searching process, on the other hand, is based on a multilevel search strategy rather than the full-search strategy used by most conventional tracking methods. Both simulated speckle images and clinical breast images were used to test the performance of the proposed algorithm. The results show that the computation efficiency is improved by up to a factor of five over the conventional approach. The improved efficiency enables real-time or near-real-time implementation of motion estimation in ultrasonic imaging, which is particularly beneficial in areas such as blood flow estimation, elasticity imaging, speckle image registration, and strain compounding.Block sum pyramid; Motion estimation; Multilevel search; Speckle tracking; Ultrasonic imagingEfficiency; Image enhancement; Imaging systems; Medical imaging; Motion estimation; Real time control; Speckle; Tracking (position); Ultrasonic imaging; Block sum pyramid; Blood flow estimation; Computation efficiency; Conventional approach; Elasticity imaging; Multi-level search; Speckle tracking; Sum of absolute differences; Motion tracking; algorithm; article; blood flow velocity; contrast radiography; diagnostic imaging; echography; image processing; simulation; strain difference; task performance; technique; ultrasoundjournal article10.1177/016173460202400402126652382-s2.0-0036820781