In vitro experimental study on relationship between bone texture parameters in sheep lumbar CT and osteoporosis
Objective To establish the sheep model of lumbar spine osteoporosis in vitro,and to search the texture parameters with identification significance and establish its regression formula relation with DXA measured bone mineral density,bone ash density and bone ash degree.Methods The L1-L3 trigeminy verte-bral body in 120 sheep conducted the immersion and decalcification by EDTA-Na2 solution (0.4916 mmol/L) immersion method,the muscles and attachment bone were removed.Then they were randomly divided into 4 groups (group A,B,C and D),30 cases in each group.They were immersed in 10％ formaldehyde solution for anticorrosion.The group A,B,C and D were immersed in the prepared EDTA-Na2 solution for decalcification 0,4,9,15 d to prepare the in vitro osteoporosis models.Thin-slice CT scan and DXA bone density measure-ment on the above-mentioned lumbar vertebrae were performed,and the volume and dry weight of each verte-bral body were measured,and then calcined at a constant temperature of 1100 ℃ in a muffle furnace for 6 h to measure the weight of ashes.The bone ash weight,bone ash density and bone ash degree were measured.The MaZda texture analysis software was used to conduct the texture analysis on the cancellous substance of the vertebral body in the above CT images,and the texture features were screened by the Fisher coefficient,classi-fication error probability combined with average correlation coefficient,interactive information and the three combined method.The 4 groups of bone mineral density conducted the classification analysis by the original data analysis (ODA),principal component analysis (PCA),linear discriminant analysis (LDA) and nonlinear discriminant analysis (NDA).The correlation analysis between the texture parameters screened by the above method with the bone density,bone grey degree and bone ash density for searching the texture parameters with strongest correlation.The texture parameters with strongest correlation served as the independent varia-bles,the bone density,bone grey degree and bone ash density as the dependent variables,and the unitary and binary linear regression analyses were performed for obtaining the regression equation.Results With the pro-longation of decalcification time,the CT images showed that the bone cortex gradually thinned,the cancellous bone density was decreased,and the trabecular bone became sparse.The identification ability of FPM com-bined with NDA was strongest,and the false judgment rate was only 2.5％.Among them,the contrast in the gray symbiosis matrix had strongly negative correlation with the bone gray degree (r=-0.938).The entropy in the gray co-occurrence matrix had strongly negative correlation with the bone ash density and bone mineral density (r=-0.927,-0.896).The unitary linear regression equation was expressed as bone grey degree=0.692-0.002×Contrast,bone ash density=0.802-0.121×Entropy,bone density=1.301-0.200×Entro-py.Conclusion The significant correlation exists between some texture parameters and bone mineral density related parameters in thin slice CT images of sheep lumbar spine,which could establish a regression formula relationship.
万方数据
维普
