DocumentCode :
873719
Title :
Estimation of the Optimal Maximum Beam Angle and Angular Increment for Normal and Shear Strain Estimation
Author :
Rao, Min ; Varghese, Tomy
Author_Institution :
Univ. of Wisconsin, Madison, WI
Volume :
56
Issue :
3
fYear :
2009
fDate :
3/1/2009 12:00:00 AM
Firstpage :
760
Lastpage :
769
Abstract :
In the current practice of ultrasound elastography, only the axial component of the displacement vector is estimated and used to produce strain images. A method was recently proposed by our group to estimate both the axial and lateral components of a displacement vector using RF echo signal data acquired along multiple angular insonification directions of the ultrasound beam. Previous work has demonstrated that it is important to choose appropriate values for the maximum beam angle and angular increment to achieve optimal performance with this technique. In this paper, we present error propagation analysis using the least-square fitting process for the optimization of the angular increment and the maximum beam steered angle. Ultrasound simulations are performed to corroborate the theoretical prediction of the optimal values for the maximum beam angle and angular increment. Selection of the optimal parameters depends on system parameters, such as center frequency and aperture size. For typical system parameters, the optimal maximum beam angle is around 10deg for axial strain estimation and around 15deg for lateral strain estimation. The optimal angular increment is around 4deg -6deg, which indicates that only five to seven beam angles are required for this strain-tensor estimation technique.
Keywords :
biomechanics; biomedical ultrasonics; elasticity; least squares approximations; RF echo signal; angular increment; displacement vector component; error propagation analysis; least-square fitting process; multiple angular insonification directions; optimal maximum beam angle; shear strain estimation; strain images; strain-tensor estimation technique; ultrasound elastography; ultrasound simulation; Apertures; Capacitive sensors; Diseases; Elasticity; Error analysis; Interpolation; Iterative algorithms; Least squares methods; Predictive models; RF signals; Radio frequency; Tensile stress; Ultrasonic imaging; Elasticity; elasticity imaging; elastogram; elastography; shear strain; stiffness; strain; strain tensors; ultrasound; Algorithms; Computer Simulation; Elasticity Imaging Techniques; Least-Squares Analysis; Models, Theoretical; Phantoms, Imaging; Stress, Mechanical; Transducers; Ultrasonography;
fLanguage :
English
Journal_Title :
Biomedical Engineering, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9294
Type :
jour
DOI :
10.1109/TBME.2008.2005907
Filename :
4633665
Link To Document :
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