Comparing lumbar computed tomography Hounsfield units and magnetic resonance imaging vertebral bone quality scores for diagnosing osteoporosis and osteopenia in degenerative spinal populations: a systematic review and diagnostic meta-analysis.
OBJECTIVES Accurate detection of impaired vertebral bone quality (VBQ) is essential for identifying patients at risk of osteoporosis-related fractures and for optimising surgical planning. Dual-energy X-ray absorptiometry (DXA) is the gold standard but is limited by degenerative artefacts and restricted availability. CT-derived Hounsfield units (HU) and MRI-derived VBQ scores provide alternatives for assessing bone quality. This meta-analysis compared HU and VBQ performance for identifying osteopenia and osteoporosis. MATERIALS AND METHODS PubMed, EMBASE, MEDLINE, and Cochrane Library were searched to September 2025. Studies reporting HU or VBQ referenced to DXA or quantitative CT were included. Continuous outcomes were pooled as standardised mean differences (SMD), and diagnostic accuracy was evaluated using bivariate hierarchical summary receiver operating characteristic models, threshold synthesis, meta-regression, and bootstrap validation. RESULTS Forty-two studies (9214 participants) were included. Both HU and VBQ distinguished impaired from normal bone quality, although HU demonstrated larger SMDs (osteopenia/osteoporosis -2.62; osteoporosis -1.53) than VBQ (0.77 and 0.81). For osteopenia, pooled areas under the ROC curve (AUCs) were 0.87 for HU and 0.75 for VBQ; for osteoporosis, AUCs were 0.86 and 0.79, respectively. Threshold synthesis identified pooled cut-offs for both modalities: 138.9 HU (osteopenia), 104.6 HU (osteoporosis), and VBQ thresholds of 2.83 and 3.14. Validation analyses consistently favoured HU, while VBQ demonstrated greater variability. CONCLUSION Both HU and VBQ offer useful assessments of vertebral bone quality, but HU provides higher and more stable diagnostic accuracy. HU thresholds may support opportunistic osteoporosis screening, but their clinical applicability remains uncertain given inter-study heterogeneity, while further refinement of MRI-based VBQ methods is warranted. KEY POINTS Question How do computed tomography attenuation and magnetic resonance imaging vertebral bone quality scoring compare in identifying osteopenia and osteoporosis on routine imaging? Findings Computed tomography attenuation measurements outperformed magnetic resonance imaging bone quality scoring, demonstrating higher sensitivity, specificity, and accuracy for detecting osteopenia and osteoporosis. Clinical relevance Routine CT and MRI can support opportunistic detection of low bone density, enabling earlier intervention, improved fracture risk stratification, and more informed preoperative assessment without additional imaging or radiation.