DocumentCode :
3229633
Title :
Chirp reversal power modulation contrast imaging
Author :
Novell, Anthony ; Bouakaz, Ayache
Author_Institution :
Univ. Francois Rabelais, Tours, France
fYear :
2011
fDate :
18-21 Oct. 2011
Firstpage :
632
Lastpage :
635
Abstract :
Chirp excitations are known to increase significantly the signal to noise ratio (SNR). Besides, we have shown in a previous study that chirp reversal (CR) approach improves the contrast detection through an increased contrast to tissue ratio (CTR). The aim of this study is to evaluate the combination of chirp reversal with power modulation (CRPM) for contrast agent imaging. Experiments were performed using a 128 elements PZT linear array probe centered at 4 MHz. The probe was connected to a fully programmable open scanner equipped with analog transmitters. Chirped signals and pulses were transmitted at 2.5 MHz with 55% bandwidth. A flow phantom was used in which SonoVue® microbubbles at a dilution of 1/2000 was introduced. RF data were recorded and then filtered using a matched filter in order to compress the scattered signals and to recover the axial resolution when chirps were used. Traditional multi-excitations schemes such as pulse inversion (PI), power modulation (PM) and their combination PIPM were implemented using pulses and chirps with or without chirp reversal approach. The use of chirp increases significantly the SNR without degrading the CTR. Compared to other methods, the combination of CR and PM increases both the CTR and the SNR. For example, the CTR using CRPM is 25.3 dB while PM alone and CR alone provided a CTR of 18.7 dB and 21.8 dB respectively.
Keywords :
biological tissues; biomedical ultrasonics; chirp modulation; phantoms; ultrasonic imaging; PZT linear array probe; RF data; SonoVue microbubbles; analog transmitters; axial resolution; chirp excitations; chirp reversal power modulation contrast imaging; chirped signals; contrast agent imaging; contrast detection; contrast to tissue ratio; flow phantom; frequency 2.5 MHz; frequency 4 MHz; fully programmable open scanner; matched filter; multiexcitations schemes; pulse inversion; scattered signals; signal to noise ratio; Acoustics; Chirp; Harmonic analysis; Imaging; Modulation; Signal to noise ratio; Ultrasonic imaging; CTR; SNR; chirps; microbubbles; nonlinear imaging;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultrasonics Symposium (IUS), 2011 IEEE International
Conference_Location :
Orlando, FL
ISSN :
1948-5719
Print_ISBN :
978-1-4577-1253-1
Type :
conf
DOI :
10.1109/ULTSYM.2011.0153
Filename :
6293392
Link To Document :
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