Predicting MRI-derived total brain volume from DXA-derived head composition in middle-aged and older adults: WASEDA'S
Toshiharu Tsutsui1,2, Suguru Torii3,4, Kumpei Tanisawa1
1Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan.
BMC Medical Imaging
|May 7, 2026
Summary
Dual-energy X-ray absorptiometry (DXA) head composition measures offer a practical way to estimate total brain volume (TBV) in older adults. This method provides a feasible alternative to resource-intensive MRI for assessing brain health.
Area of Science:
- Neuroimaging
- Biomarkers
- Gerontology
Background:
- Total brain volume (TBV) from MRI is crucial for brain health assessment in aging populations.
- MRI's resource intensity limits its use in large-scale or repeated studies.
- Exploring alternative methods like DXA for TBV estimation is essential.
Purpose of the Study:
- To investigate if dual-energy X-ray absorptiometry (DXA)-derived head composition can estimate MRI-derived TBV.
- To assess the feasibility of DXA as a substitute for MRI in middle-aged and older adults.
- To validate the accuracy and reliability of DXA-based TBV estimation.
Main Methods:
- 314 participants (≥40 years) underwent both whole-body DXA and 3T brain MRI.
- Multivariable linear regression models were developed using DXA-derived head lean-and-fat mass or head fat mass.
- Model performance was evaluated using R², RMSE, bootstrap validation, and Bland-Altman analysis.
Main Results:
- DXA-derived head lean-and-fat mass and head fat mass positively correlated with TBV.
- Age was negatively associated with TBV, while male sex was associated with larger TBV.
- Models showed favorable calibration (CITL ≈ 0, slope ≈ 1.00) and stable internal validation.
Conclusions:
- DXA-derived head composition provides a practical approximation of MRI-derived TBV.
- The method demonstrates good calibration and stable performance in middle-aged and older adults.
- DXA offers a feasible alternative for large-scale brain health assessments.
