Forma, Vol. 6 (No. 3), pp. 181-191, 1991
Original Paper

Spatial Distribution of the Peripheral Airways—Application of Fractal Geometry

Hiroko Kitaoka1 and Harumi Itoh2

1Department of Internal Medicine, Kitaoka Hospital, Kurayoshi, Japan
2Department of Radiology, Kyoto University School of Medicine, Kyoto, Japan

(Received March 4, 1991; Accepted April 6, 1991)

Keywords: Airways, Fractal, Three-Dimensional Reconstruction

Abstract. We examined the spatial distribution of peripheral airways applying fractal geometry. Part of a normal fixed lung specimen resected because of a small lung cancer was used. Reconstructed three-dimensional images of peripheral airways from a sub-sub segmental bronchus to its terminal bronchioli were processed using a personal computer from serial thin-sliced (0.5-mm) lung specimens. These data were used to examine whether spatial distribution of the peripheral airways has selfsimilarity. A three-dimensional box-counting method was applied using the computer system and fractal dimensions were measured at three different areas. The results indicated that the spatial distribution of the airways is approximately self-similar with fractal dimensions 1.7 in all areas. It was interpreted that spatial structural style of airways could be represented quantitatively by fractal geometry.