Magnetic resonance imaging-derived vertebral bone quality correlates with computed tomography-derived bone density and paraspinal muscle degeneration: a systematic review and meta-analysis

STUDY DESIGN: Systematic review and meta-analysis. PURPOSE: To quantitatively synthesize the relationship between magnetic resonance imaging (MRI)-derived vertebral bone quality (VBQ) and computed tomography (CT)-derived Hounsfield units (HU), and paraspinal muscle characteristics. OVERVIEW OF LITERATURE: Osteoporosis and sarcopenia frequently coexist as "osteosarcopenia," representing degeneration of the "bone-muscle unit." MRI-derived VBQ is an emerging opportunistic imaging biomarker; however, its physiological validity relative to CT-derived HU and paraspinal muscle degeneration remains ill-defined. METHODS: A systematic review and meta-analysis (according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines) was conducted to explore relevant literature reporting quantitative associations between VBQ, HU, and paraspinal muscle metrics in the PubMed, Embase, Scopus, and Web of Science databases up to December 9, 2025. Reported correlation coefficients were pooled using random-effects models with Fisher's Z transformation. An exploratory regression synthesis was performed using reconstructed individual participant data. RESULTS: We included 24 studies with 4,447 patients. VBQ demonstrated a moderate inverse correlation with CT-derived HU (pooled r=-0.55; 95% confidence interval [CI], -0.65 to -0.43; findings consistent across cervical and lumbar regions), a small negative association with paraspinal muscle cross-sectional area (r=-0.19), but a strong positive association with muscle fat infiltration (r=0.63). In contrast, HU was positively associated with muscle size and negatively associated with fat infiltration. Reconstructed data yielded an exploratory translation model: HU=-50.9×VBQ+378. CONCLUSIONS: VBQ correlates robustly with CT-derived bone density and paraspinal myosteatosis, supporting its role as an imaging marker of the bone-muscle unit in the spine. While CT-derived HU remains essential for absolute bone assessment, VBQ offers a radiation-free, opportunistic tool for identifying patients with compromised musculoskeletal integrity (PROSPERO registration number: CRD420251238599).