title: Non-invasive vascular radial/circumferential strain imaging and wall shear rate estimation using video images of diagnostic ultrasound.
abstract: The aim of this work was to develop a convenient method for radial/circumferential strain imaging and shear rate estimation that could be used as a supplement to the current routine screening for carotid atherosclerosis using video images of diagnostic ultrasound. A reflection model-based correction for gray-scale non-uniform distribution was applied to B-mode video images before strain estimation to improve the accuracy of radial/circumferential strain imaging when applied to vessel transverse cross sections. The incremental and cumulative radial/circumferential strain images can then be calculated based on the displacement field between consecutive B-mode images. Finally, the transverse Doppler spectra acquired at different depths along the vessel diameter were used to construct the spatially matched instantaneous wall shear values in a cardiac cycle. Vessel phantom simulation results revealed that the signal-to-noise ratio and contrast-to-noise ratio of the radial and circumferential strain images were increased by 2.8 and 5.9 dB and by 2.3 and 4.4 dB, respectively, after non-uniform correction. Preliminary results for 17 patients indicated that the accuracy of radial/circumferential strain images was improved in the lateral direction after non-uniform correction. The peak-to-peak value of incremental strain and the maximum cumulative strain for calcified plaques are evidently lower than those for other plaque types, and the echolucent plaques had higher values, on average, than the mixed plaques. Moreover, low oscillating wall shear rate values, found near the plaque and stenosis regions, are closely related to plaque formation. In conclusion, the method described can provide additional valuable results as a supplement to the current routine ultrasound examination for carotid atherosclerosis and, therefore, has significant potential as a feasible screening method for atherosclerosis diagnosis in the future.
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Jinjin
authors.initials: J
authors.lastname: Wan
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Fangli
authors.initials: F
authors.lastname: He
authors.affiliation: Department of Ultrasound, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Ultrasound, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhou
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China. Electronic address: mxwan@mail.xjtu.edu.cn.
authors.forename: Mingxi
authors.initials: M
authors.lastname: Wan
mesh_terms: D000328:Adult; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D055119:Elastic Modulus / Q000502:physiology; D054459:Elasticity Imaging Techniques / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D033081:Shear Strength / Q000502:physiology; D013314:Stress, Mechanical; D014741:Video Recording / Q000379:methods*
keywords: Atherosclerosis; Carotid; Circumferential strain; Gray-scale correction; Radial strain; Routine screening; Transverse Doppler; Wall shear rate