Small calcification depiction in ultrasound B-mode images using decorrelation of echoes caused by forward scattered waves.
OBJECTIVE
The purpose of this study is to propose a novel method to depict small calcifications in ultrasound B-mode images using decorrelation of forward scattered waves with no decrease in the frame rate.


METHODS
Since the waveform of an ultrasound pulse changes when it passes through a calcification location, the echo waveform from regions behind the calcification is quite different from that without a calcification. This indicates that the existence of a calcification is predictable based upon the waveform difference between adjacent scan lines by calculating cross-correlation coefficients. In addition, a high-intensity echo should return from the calcification itself. Therefore, the proposed method depicts the high-intensity echo positions with posterior low correlation coefficient regions.


RESULTS
Eleven of 15 wires 0.2-0.4 mm in diameter were depicted using this method, yielding a sensitivity of 73.3% and a specificity of 100%, even though they might go undetected under clinical inspection of ultrasound B-mode images.


CONCLUSIONS
This study suggests that an US device could perform well in terms of calcification detection.
Graduate School of Informatics, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto, 606-8501, Japan. hirofumi.taki@mb6.seikyou.ne.jp.
Hirofumi
H
Taki
Graduate School of Informatics, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto, 606-8501, Japan.
Takuya
T
Sakamoto
Advanced Biomedical Engineering Research Unit, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto, 606-8501, Japan.
Makoto
M
Yamakawa
Graduate School of Medicine, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto, 606-8501, Japan.
Tsuyoshi
T
Shiina
Corporate R&D HQ, Canon Inc, 30-2, Shimomaruko 3-chome, Ohta-ku, Tokyo, 146-8501, Japan.
Kenichi
K
Nagae
Graduate School of Informatics, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto, 606-8501, Japan.
Toru
T
Sato
Calcification; Calcification detection; Decorrelation; Forward scattered wave; Ultrasonography