DocumentCode :
2974057
Title :
3D simulations of difference frequency effects on a blood vessel in ultrasound-stimulated vibro-acoustography
Author :
Heikkilä, Janne ; Karjalainien, T. ; Vauhkonen, Marko ; Hynynen, Kullervo
Author_Institution :
Dept. of Appl. Phys., Kuopio Univ., Finland
Volume :
2
fYear :
2004
fDate :
23-27 Aug. 2004
Firstpage :
1247
Abstract :
Ultrasound-stimulated vibro-acoustography (USVA) is one of the recent noninvasive techniques that have been developed to explore mechanical properties of soft tissues. USVA is based on the interference of two focused ultrasound beams that have a slightly different frequency. This interference produces time variation to the acoustic radiation force that vibrates the joint focal region at the difference frequency. In this paper, we have simulated displacement amplitudes in the blood vessel using different difference frequencies and elasticity parameters. The difference frequency was varied between 300 Hz and 2.5 kHz, and two different stiffness parameters (60 kPa and 120 kPa) for the blood vessel wall were used. The stimulation transducer used in the simulations consists of two concentric and focused ring elements whose base frequency is 0.75 MHz. The stimulation fields have been computed in a homogeneous domain using the Rayleigh integral. The simulations of the vibrations have been computed using the finite element method. The displacement simulations are computed in an inhomogeneous domain that consists of soft tissue and a blood vessel. From the simulations, it can be seen that USVA is sensitive to the mechanical properties of vessel wall and that the displacements are highly dependent on the difference frequency and the material parameters.
Keywords :
biomedical ultrasonics; blood vessels; displacement measurement; elasticity; finite element analysis; inhomogeneous media; integral equations; simulation; ultrasonic focusing; ultrasonic imaging; ultrasonic transducers; 3D simulations; Rayleigh integral; USVA; acoustic radiation force; blood vessel; blood vessel wall; difference frequency effects; displacement amplitudes; elasticity parameters; finite element method; focused ultrasound beams; inhomogeneous domain; mechanical properties; noninvasive techniques; soft tissues; stiffness parameters; stimulation transducer; ultrasound-stimulated vibro-acoustography; Acoustic beams; Biological tissues; Blood vessels; Computational modeling; Elasticity; Frequency; Interference; Mechanical factors; Noninvasive treatment; Ultrasonic imaging;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultrasonics Symposium, 2004 IEEE
ISSN :
1051-0117
Print_ISBN :
0-7803-8412-1
Type :
conf
DOI :
10.1109/ULTSYM.2004.1418014
Filename :
1418014
Link To Document :
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