Assessment of Bone Mineral Density in Patients With Degenerative Spinal Disease by MRI-based Vertebral Bone Quality Score at Different Lumbar Vertebral Levels

STUDY DESIGN: Prospective observational cohort study. OBJECTIVE: To prospectively evaluate the utility of traditional and single-level vertebral bone quality (VBQ) scores for preoperative bone mineral density (BMD) assessment in patients undergoing lumbar fusion surgery, and to validate their diagnostic performance against dual-energy x-ray absorptiometry (DEXA) and quantitative computed tomography (QCT). SUMMARY OF BACKGROUND DATA: Magnetic resonance imaging (MRI)-based VBQ score has been proposed to assess BMD, but prospective evidence comparing different vertebral levels is lacking. MATERIALS AND METHODS: Participants were classified into normal, osteopenia, and osteoporosis groups based on DEXA T -score and QCT-vBMD. Intergroup differences were analyzed, with post hoc corrections for multiple comparisons. Correlations between VBQ scores and BMD were evaluated, while receiver operating characteristic (ROC) analysis assessed their diagnostic performance. Linear and logistic regression models were further applied to examine the independent association between VBQ scores and osteoporosis. RESULTS: Among 198 patients (58.9±11.8 yr; 56.6% female), groups differed significantly in age and sex ( P <0.001). VBQ scores varied significantly across groups and were negatively correlated with both DEXA T -score and QCT-vBMD at most vertebral levels, with stronger correlations observed for QCT ( r =-0.412 to -0.563). ROC analysis confirmed that VBQ scores effectively differentiated normal, osteopenia, and osteoporosis. Multivariable regression identified higher L1-L4 VBQ scores as independent predictors of lower BMD (DEXA: β=-0.412; QCT: β=-0.469) and increased osteoporosis risk (DEXA: OR=3.201, 95% CI=1.056-9.704; QCT: OR=2.741, 95% CI=1.061-7.080). CONCLUSION: This prospective study demonstrated that the L1-L4 VBQ score exhibited superior stability and generalizability compared with single-level measurements, supporting its potential use as a practical surrogate marker for opportunistic BMD screening in patients undergoing spinal surgery. Specific single-level scores, such as those at L1, L2, and S1, may still provide supplementary diagnostic value in detecting early bone quality alterations. LEVEL OF EVIDENCE: Level 2.