Figure 1.
Calculation of stochastic predictors from the BMD map of human vertebrae. (a) A DXA image of a human vertebra in the PA projection from Hologic densitometers; (b) A typical BMD map obtained from the raw data of DXA scans of human vertebrae; (c) A hole-effect fitting model of the experimental variogram of the BMD map. The stochastic predictors, correlation length (L), sill variance (c) and nugget variance (c0), were extracted from the hole-effect model; and (d) An exponential fitting model of the experimental variogram of the BMD map.