Original Jpn J Radiol Technol 2000 ;
Imaging Analysis of Trabeculae

AKIRA KITAYAMA, MICHINOBU ITAYA, TATSUSHI TOMOMITSU,1) SHIN-ICHI ARAO, TAKASHI AMANO, AKIKO HAYASHI, TERUKI SONE,2) MASAO FUKUNAGA,2) and KAZUYA YAMASHITA
Department of Radiological Technology, Kawasaki College of Allied Health Professions
1)Department of Radiology, Kawasaki Medical School Hospital
2)Department of Nuclear Medicine, Kawasaki Medical School
Received Nov. 17, 1999; Revision accepted Jan. 24, 2000; Code No. 522

Summary
In order to support the diagnosis of osteoporosis by the quantitative determination of bone strength, we examined a pre-processing method for extracting trabeculae and a quantitative method of analyzing the characteristics of trabeculae by imaging. The results indicated that both density-exposure conversion and background trend correction(smoothing filter method, rolling ball method)were effective pre-processing methods for extracting trabeculae. Image analysis of bone trabecular characteristics showed that there was a significant weak negative correlation(r = - 0.26, p = 0.011)between the number of vertical trabeculae on lateral lumbar vertebral images and lumbar bone mineral density. In addition, there were significant
positive correlations(r = 0.510~0.678, p < 0.0029~0.0426)between the spatial frequency of calcaneal trabecular images estimated by our newly developed method of analyzing spatial frequency and bone mass indices obtained by the QUS/SXA apparatus for quantifying bone mass. There were significant high correlations(r = 0.608~0.820, p < 0.0001~0.0109)between the fractal dimension of calcaneal trabecular
images and bone mass indices. In conclusion, it was shown that the values obtained from analysis were correlated with bone elasticity and bone density.

Key words: Digital image analysis, Trabecular bone, Spatial frequency analysis, Fractal dimension analysis, Osteoporosis