Investigation of Postmenopausal Alteration of Trabecular Structure on Calcaneus Radiographs Using Various Fractal Analysis Methods

Four different methods of fractal analysis able to analyze grayscale images were applied to trabecular structure of the calcaneus, as it appears on the plain lateral radiograph. Their capacity to recognize a radiograph as belonging to a pre- or postmenopausal group was investigated. The study used 3 different regions of interest (ROI), after digital processing. Two-tailed p-value was calculated to compare the results. K-means clustering, nearest neighbor (1-nn) and 3-nearest neighbor (3-nn) algorithms ' were used to objectively assess the ability of these analysis methods to discriminate the two sets of radiographs. Using these methods, 19 out of 24 X-rays were correctly classified (p = 0.004).