DocumentCode :
1945989
Title :
Theoretical study of harmonic generation sound beams in case of uniform, exponential and cosinusoidal apertures
Author :
Kourtiche, D. ; Ali, L. Ait ; Chitnalah, A. ; Nadi, M.
Author_Institution :
LIEN, Univ. H. Poincare Nancy 1, Vandoeuvre les Nancy, France
Volume :
3
fYear :
2001
fDate :
2001
Firstpage :
2395
Abstract :
The non-linear propagation of ultrasound in medical imaging has recently been exploited to improve image resolution and remove near field artifacts generated by overlying tissue structures. The images are formed using the second harmonic energy generated by nonlinear propagation. Second harmonic beams have narrower beam width and lower side lobes than the fundamental. The second harmonic draws energy from the fundamental continuously along the propagation path. These characteristics contribute to improve the quality of medical ultrasound images. In this paper, our objective is to show that the choice source aperture has significant consequences on the quality of the field transmitted in terms of directivity. We also studied the field generated by three apertures sources, in a nonlinear medium. A theoretical approach, based on the Khokhlov-Zabolotskaya-Kuznetsov (KZK) parabolic approximation is used in order to consider the diffraction effects related to the use of a focusing real source. The fundamental ultrasonic fields and the second harmonic are compared at three distances from the source. Width and side lobes were used when recording three distributions of the beam form.
Keywords :
biological tissues; biomedical ultrasonics; harmonic generation; image resolution; nonlinear acoustics; ultrasonic diffraction; ultrasonic focusing; Khokhlov-Zabolotskaya-Kuznetsov parabolic approximation; beam form distributions; choice source aperture; cosinusoidal apertures; diffraction effects; directivity; exponential apertures; focusing real source; fundamental; fundamental ultrasonic fields; harmonic generation sound beams; image resolution; lower side lobes; medical imaging; medical ultrasound image quality; narrower beam width; near field artifacts; nonlinear propagation; overlying tissue structures; propagation path; second harmonic energy; side lobes; transmitted field quality; ultrasound nonlinear propagation; uniform apertures; Absorption; Acoustic beams; Acoustic distortion; Acoustic propagation; Apertures; Computer aided software engineering; Focusing; Frequency conversion; Linearity; Ultrasonic imaging;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Engineering in Medicine and Biology Society, 2001. Proceedings of the 23rd Annual International Conference of the IEEE
ISSN :
1094-687X
Print_ISBN :
0-7803-7211-5
Type :
conf
DOI :
10.1109/IEMBS.2001.1017259
Filename :
1017259
Link To Document :
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