[1] [1] L. V. Wang, Disease Markers 19, 123 (2004).

[2] [2] R. A. Kruger, K. Stantz, and W. L. Kiser, Proc. SPIE 4682, 521 (2002).

[3] [3] Y. Zeng, D. Xing, Y. Wang, B. Yin, and Q. Chen, Opt. Lett. 29, 1760 (2004).

[4] [4] Y. Su, F. Zhang, K. Xu, J. Yao, and R. K. Wang, J. Phys. D 38, 2640 (2005).

[5] [5] A. A. Karabutov, E. V. Savateeva, N. B. Podymova, and A. A. Oraevsky, J. Appl. Phys. 87, 2003 (2000).

[6] [6] U. Oberheide, B. Jansen, I. Bruder, H. Lubatschowski, H. Welling, and W. Ertmer, Proc. SPIE 4434, 1 (2001).

[7] [7] M. Xu, Y. Xu, and L. V. Wang, IEEE Trans. Biomed. Eng. 50, 1086 (2003).

[8] [8] V. G. Andreev, A. A. Karabutov, and A. A. Oraevsky, IEEE Trans. Ultrasonics, Ferroelectrics and Frequency Control 50, 1383 (2003).

[9] [9] M. Xu and L. V. Wang, IEEE Trans. Medical Imaging 21, 814 (2002).

[10] [10] R. A. Kruger, W. L. Kiser, K. D. Miller, H. E. Reynolds, D. R. Reinecke, G. A. Kruger, and P. J. Hofacker, Proc. SPIE 3916, 150 (2000).

[11] [11] S. L. Jacques, R. D. Glickman, and J. A. Schwartz, Proc. SPIE 2681, 468 (1996).

[12] [12] G. Ku, X. Wang, G. Stoica, and L. V. Wang, Physics in Medicine and Biology 49, 1329 (2004).