3D-DXA imaging shows strong correlation with QCT for assessing femoral bone density in international cohorts.

This observational cohort study evaluated 537 subjects drawn from four distinct populations: an adult group from Spain, a postmenopausal female group from the United States, and two osteoarthrosis or young populations from Japan. The primary objective was to assess the accuracy of 3D-DXA parameters against quantitative computed tomography (QCT), specifically focusing on integral volumetric bone mineral density, trabecular volumetric bone mineral density, and cortical subperiosteal bone mineral density.

The analysis revealed strong correlations between 3D-DXA and QCT across all datasets, with correlation coefficients ranging between 0.82 and 0.97. However, random errors for integral volumetric bone mineral density ranged between 16.55 and 19.91 mg/cm3, while trabecular volumetric bone mineral density errors ranged between 13.52 and 18.47 mg/cm3. Cortical subperiosteal bone mineral density random errors were smaller, ranging between 9.13 and 11.37 mg/cm2.

Systematic errors were observed and attributed to differences in QCT acquisition protocols. For integral volumetric bone mineral density, these ranged between -14.84 and 4.50 mg/cm3; trabecular volumetric bone mineral density systematic errors ranged between -8.31 and 14.41 mg/cm3; and cortical subperiosteal bone mineral density errors ranged between -5.58 and 3.21 mg/cm2. Adverse events, serious adverse events, discontinuations, and tolerability were not reported. A key limitation noted was that variations in systematic errors were likely attributable to differences in QCT acquisition protocols.

The study supports the use of 3D-DXA as an accurate, non-invasive, and clinically accessible technology for advanced assessment of the cortical and trabecular compartments of the proximal femur. Clinicians should interpret these results with caution regarding the impact of QCT acquisition variations on systematic error measurements.