DocumentCode :
1361069
Title :
A consistent tissue attenuation coefficient estimator using bubble harmonic echoes
Author :
Tsao, Sheng-Kai ; Tsao, Jenho
Author_Institution :
Grad. Inst. of Commun. Eng., Nat. Taiwan Univ., Taipei, Taiwan
Volume :
57
Issue :
12
fYear :
2010
fDate :
12/1/2010 12:00:00 AM
Firstpage :
2654
Lastpage :
2661
Abstract :
The ultrasonic property of soft tissue can be quantified by its attenuation coefficient α. Traditionally the backscattering signal of tissue is used to estimate α. To improve precision, a large number of spatially independent samples of tissue echoes are required for averaging. In this paper, we propose a new estimation method, which makes use of microbubbles to provide temporally independent samples for averaging. It is easier for temporal sampling to maintain ergodicity and provide a large number of independent samples for statistical averaging. A stochastic model for the harmonic signals of an ideal bubble attenuated by tissue is derived based on Kuc´s and Miller´s works. An estimator of α is then presented. This estimator is consistent and could be biased because of the unknown squarelaw relation between the second and fundamental harmonics for non-ideal bubble oscillation. In experimental works, we design a simplified phantom for demonstrating the performance of the proposed estimator. It is shown that both first and second harmonics can estimate α consistently. However, the interference of the tissue backscattering signal may cause additional estimation error using the first harmonic.
Keywords :
acoustic signal processing; bioacoustics; biological tissues; biomedical ultrasonics; bubbles; cellular biophysics; echo; estimation theory; harmonic generation; medical signal processing; phantoms; stochastic processes; ultrasonic dispersion; ergodicity; first harmonics; harmonic signals; microbubble harmonic echoes; phantom; second harmonics; signal backscattering; soft tissue; square-law relation; stochastic model; tissue attenuation coefficient estimator; ultrasonic property; Attenuation; Backscatter; Blood flow; Echo cancellers; Harmonic analysis; Logic gates; Power system harmonics; Algorithms; Contrast Media; Microbubbles; Models, Biological; Phantoms, Imaging; Signal Processing, Computer-Assisted; Stochastic Processes; Ultrasonography;
fLanguage :
English
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
Publisher :
ieee
ISSN :
0885-3010
Type :
jour
DOI :
10.1109/TUFFC.2010.1739
Filename :
5610551
Link To Document :
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