Makoto IGARASHI^1,*, Kazuhiro GONO^1,2, Takashi OBI¹, Masahiro YAMAGUCHI¹ and Nagaaki OHYAMA³

¹Imaging Sciences and Engineering Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-chou, Midori-ku, Yokohama-shi, Kanagawa 226-8503, Japan
²Olympus Optical Co., Ltd., Ishikawa-cho, Hachioji-shi, Tokyo 192-8507, Japan
³Frontier Collaborative Research Center, Tokyo Institute of Technology, 4259 Nagatsuta-chou, Midori-ku, Yokohama-shi, 226-8503, Japan

(Received November 20, 2003; Accepted February 5, 2004)

We made a tissue phantom with double-peak particle size distribution, which has polystyrene particles of cell nuclear size and mitochondrial size, and measured the spectrum from the tissue phantom using a single optical fiber. In this paper we investigate the characterization method for the tissue phantom with double-peak particle size distribution by comparing the measured spectra with the calculated ones using the Monte Carlo (MC) method. It is first shown that the Mie phase function characterizes better than the Henyey-Greenstein (H-G) phase function in MC calculation. Next, we compare the measurement spectra with those obtained by modeling as single-peak, conventional modeling for particle size distribution, and for double-peak particle size distribution. The single-peak modeling is found to cause considerable error for the tissue phantom with double-peak particle size distribution, which seems to simulate a biological tissue. We suggest that if one simulates the particle size distribution of a biological tissue by conventional modeling, the accuracy of estimation will be lower.

Key words: Monte Carlo method, Mie theory, Henyey-Greenstein phase function, particle size distribution, tissue phantom

^*E-mail address: migarac@isl.titech.ac.jp