Vertebral Bone Quality (VBQ) as a Novel MRI-Based Assessment Tool: Is It an Alternative to the Time-Tested Dual-Energy X-ray Absorptiometry (DEXA) Scan?

Purpose To compare CT-derived Hounsfield units (HU) and MRI-based vertebral bone quality (VBQ) scores with dual-energy X-ray absorptiometry (DEXA), and to evaluate their diagnostic performance for identifying osteoporosis. Overview of the literature DEXA is the gold standard for assessing bone mineral density (BMD), but it has limitations, including radiation exposure and interference from degenerative changes. HU and VBQ are promising, radiation-free imaging techniques assessing different aspects of bone health: HU reflects trabecular bone density, while VBQ quantifies marrow fat content, inversely related to bone strength. Methods This study is a retrospective analysis of 112 adults who underwent lumbar spine DEXA, CT, and MRI within 30 days. HU was measured at the L3 vertebral body on CT, and VBQ scores were derived from MRI by comparing vertebral signal intensities to cerebrospinal fluid. Correlations with DEXA T-scores and diagnostic performance metrics, including receiver operating characteristic (ROC) analysis, were assessed. Results HU values demonstrated a positive correlation with DEXA T-scores (r = 0.549, p < 0.001), with decreasing HU values as BMD worsened. VBQ scores showed a weaker, non-significant correlation (r = -0.175, p = 0.064). HU exhibited higher diagnostic accuracy (area under the curve (AUC) = 0.90) than VBQ (AUC = 0.75). Combination testing improved diagnostic performance: series testing (both HU ≤ 110 and VBQ ≥ 3.9) showed 50% sensitivity and 83% specificity, while parallel testing (either HU ≤ 110 or VBQ ≥ 3.9) demonstrated 86% sensitivity and 51% specificity. Conclusions CT-derived HU and MRI-based VBQ scores are complementary biomarkers for osteoporosis assessment. HU offers strong diagnostic accuracy, while VBQ provides a radiation-free alternative. The combination of both methods enhances diagnostic performance, making them valuable for osteoporosis screening, especially when DEXA is unavailable.