Three-dimensional quantitative CT of the proximal femur: relationship to vertebral trabecular bone density in postmenopausal women.

Dual-photon absorptiometry (DPA) of the proximal femur cannot independently measure cortical and high-turnover cancellous bone. In this investigation, integrated cancellous, cortical, and total bone densities in the femoral neck and intertrochanteric region were measured bilaterally in 22 women aged 42-75 years. Contiguous section data were analyzed with two different protocols by means of three-dimensional histogram software. Single-section quantitative computed tomography (CT) was used to determine mean mineral equivalent values for vertebral cancellous bone from T-11 to L-3 in each woman. Significant correlation was found between cancellous bone density at the two sites, as well as between total femoral and vertebral measurements. Femoral cortical bone density was predicted less well by means of the vertebral cancellous data. Cortical, cancellous, and total proximal femoral density values tended to exhibit bilateral symmetry. Quantitative three-dimensional volumetric CT affords comprehensive evaluation of proximal femoral mineral status because of its capability for selective measurement of cortical, cancellous, and total bone density.