Discriminability of fracture and nonfracture cases based on the spatial distribution of spinal bone mineral.
PURPOSE: The purpose of our study is to demonstrate that spinal mineral distribution measured with CT can distinguish normal from osteoporotic individuals. METHOD: CT studies of lumbar vertebrae (L1-L3) from 121 clinically normal women without fractures and 57 women with one or more atraumatic fractures somewhere in the skeleton were evaluated with discriminant analysis based on indices of the spatial distribution and noise properties of spinal bone mineral density (BMD). RESULTS: The use of discriminant analysis for all of the normal and osteoporotic women (L1-L3) resulted in a classification accuracy of 87.1% for fracture cases and 83.2% for nonfracture cases. In contrast, using the conventional method in the same patient population, 62.5% of BMD values of osteoporotics overlapped with those of normals whose BMD was below the 90th centile of osteoporotics. CONCLUSIONS: CT-based measures of the spinal mineral distribution can increase the accuracy of discriminating fracture and nonfracture cases almost to 90% accuracy, even in a region below the fracture threshold. This shows that in this region the risk of fracture is not completely random but has a stochastic component as well.