High definition macroradiography was used to provide an image of the detailed structural organization of the cancellous bone in human lumbar vertebrae. The fractal signature analysis (FSA) method was used to quantify the horizontal and vertical trabecular organization recorded within the image. Comparison of the FSA of the postero-anterior and lateral macroradiographs in postmortem lumbar vertebrae showed that neither the superimposition of the neural arch nor the radiographic angle affected the trabecular measurement within the vertebral body. FSA analysis of the trabecular structure measured from the macroradiographs of lumbar vertebrae in two groups of postmenopausal women, with high and low bone mineral density (BMD), showed that the large vertical trabecular structures correlated with the women's body weight (P < 0.01-0.03) and body mass index (P < 0.005-0.05), the fine horizontal structures correlated with the women's age (P < 0.005-0.05), and fine vertical trabecular structures were significantly greater (P < 0.005-0.05) in the low compared with the high BMD group.