Title :
P2B-1 Estimation of Tissue Attenuation Coefficients Using Contrast Agent
Author :
Tsao, Sheng-Kai ; Tsao, Jenho
Author_Institution :
Graduate Inst. of Commun. Eng., National Taiwan Univ., Taipei
Abstract :
Attenuation coefficient (Att. Coef.) is an acoustic parameter for tissue characterization. Two major techniques for Att. Coef. estimation are the backscattering and transmission methods. Backscattering method is suitable for general applications, but the speckle interference makes it inaccurate. Transmission method is more reliable, but it is suitable for peripheral organs only, due to the need of a separate transmitter. With the aid of contrast agent (microbubble), a new way to estimate the Att. Coef. of soft tissues is proposed, which is suitable for general applications. Since microbubble is a highly nonlinear object, using the multiple frequencies generated by microbubbles behind the tissue, the Att. Coef. can be estimated in transmission mode. Since the harmonics are generated by common microbubbles, their relative strengths can be predicted by theory and measured for Att. Coef. estimation. The power spectrum of echo signals are estimated using periodogram. For liver tissue, the frequency dependent Att. Coef. (beta) is estimated as 0.1 dB/cm/MHz. Additional performances of the new technique will be evaluated further in the future
Keywords :
bioacoustics; biological tissues; biomedical ultrasonics; bubbles; nonlinear acoustics; ultrasonic absorption; ultrasonic scattering; ultrasonic transmission; acoustic parameter; backscattering methods; contrast agent; echo signal power spectrum; liver tissue; microbubble generated multiple frequencies; periodogram; speckle interference; tissue attenuation coefficient estimation; tissue characterization; transmission methods; Acoustic measurements; Attenuation measurement; Backscatter; Instruments; Interference; Liver; Power system harmonics; Speckle; Ultrasonic imaging; Ultrasonic variables measurement;
Conference_Titel :
Ultrasonics Symposium, 2006. IEEE
Conference_Location :
Vancouver, BC
Print_ISBN :
1-4244-0201-8
Electronic_ISBN :
1051-0117
DOI :
10.1109/ULTSYM.2006.399