[New evaluation for osteoporosis using calcaneal computed radiographs].

Quantitative analysis of bone mass is a method mainly used for the diagnosis of osteoporosis. However, there are cases of osteoporosis that cannot be diagnosed by this method alone. This study was performed to develop a new quantitative method for the evaluation of osteoporosis using texture analysis and geometric feature analysis of trabecular bone on lateral calcaneal computed radiographs. Thirty-seven cases including 11 normal and 26 abnormal lateral calcaneal radiographs were examined. The patients' ages ranged from 24 to 89 years (average age, 58.3 years). The root mean square (RMS) variation and first moment of power spectrum of trabecular bone patterns were determined as quantitative measures for texture analysis. In addition, the total area and total length of trabecular bone were obtained from geometric feature analysis. The RMS variations in pixel values, total area, and total length of trabecular bone were decreased as bone atrophy progressed. These three quantitative measures corresponded well to radiologists' subjective evaluations of bone atrophy. Moreover, our results indicated that these three quantitative measures had strong correlations with bone mineral density of the femoral neck. Therefore, we consider the computerized method with texture analysis and geometric feature analysis of lateral calcaneal radiographs to be very useful for radiologists in evaluating osteoporosis.