TY - JOUR
T1 - Reduction of influence of decrease in SNR of ultrasonic pulse during cardiac cycle in measurement of small change in thickness of arterial wall
AU - Hasegawa, Hideyuki
AU - Kanai, Hiroshi
AU - Hoshimiya, Nozomu
AU - Koiwa, Yoshiro
PY - 1999/12/1
Y1 - 1999/12/1
N2 - We have previously proposed a method for measuring the small change in thickness of the arterial wall during the cardiac cycle [1][2], which cannot be measured from conventional B-mode or M-mode images because of its small amplitude of less than 100 micrometer. However, in spite of its great usefulness for in vivo assessment of the local elasticity of the arterial wall, there are cases where successful measurements based on only two consecutive echo signals fail because of low signal-to-noise ratio (SNR) during the cardiac cycle. To realize the proposed method in practical use, this problem must be overcome. In this paper, we propose a method that is more robust in the presence of noise. In this method, more than two echo signals are employed in estimation of their phase shift for reducing the influence of low SNR. Simulation experiments provide the optimal value of the estimation period (the number of echo signals) for each SNR. By evaluating the SNR of in vivo experimental data, the optimal estimation period is determined. In in vivo experiment, by using the optimal estimation period of 20 ms, the change in thickness can be measured with good reproducibility even in the case of low SNR of 28 dB.
AB - We have previously proposed a method for measuring the small change in thickness of the arterial wall during the cardiac cycle [1][2], which cannot be measured from conventional B-mode or M-mode images because of its small amplitude of less than 100 micrometer. However, in spite of its great usefulness for in vivo assessment of the local elasticity of the arterial wall, there are cases where successful measurements based on only two consecutive echo signals fail because of low signal-to-noise ratio (SNR) during the cardiac cycle. To realize the proposed method in practical use, this problem must be overcome. In this paper, we propose a method that is more robust in the presence of noise. In this method, more than two echo signals are employed in estimation of their phase shift for reducing the influence of low SNR. Simulation experiments provide the optimal value of the estimation period (the number of echo signals) for each SNR. By evaluating the SNR of in vivo experimental data, the optimal estimation period is determined. In in vivo experiment, by using the optimal estimation period of 20 ms, the change in thickness can be measured with good reproducibility even in the case of low SNR of 28 dB.
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M3 - Conference article
AN - SCOPUS:0033294037
VL - 2
SP - 1337
EP - 1340
JO - Proceedings - IEEE Ultrasonics Symposium
JF - Proceedings - IEEE Ultrasonics Symposium
SN - 1051-0117
T2 - 1999 IEEE Ultrasonics Symposium
Y2 - 17 October 1999 through 20 October 1999
ER -