From Detection to Decision: T-Score-Guided Use of STIR MRI After CT in Vertebral Fractures

Background/Objectives: Vertebral fractures are frequently underdiagnosed after minor trauma in patients with normal or mildly reduced bone mineral density (BMD). CT, the standard first-line imaging, may miss subtle fractures, while STIR MRI is more sensitive but not routinely applied. We evaluated whether DEXA-derived T-scores can guide selective use of STIR MRI in patients > 50 years. Methods: We retrospectively analyzed 214 patients who underwent CT, sagittal whole-spine STIR MRI, and DEXA within 48 h after minor trauma. Fracture counts were compared using the Wilcoxon signed-rank test. Spearman's correlation examined associations between T-score and fracture counts. Subgroups were defined as normal (≥-1), osteopenia (-2.5 < T-score < -1), osteoporosis (-3.5 < T-score ≤ -2.5), and high-risk osteoporosis (≤-3.5). Results: STIR MRI identified more fractures than CT in 87 patients (40.7%), while CT detected more in 19 (8.9%) (p < 0.0001). MRI outperformed CT across all T-score categories. The osteopenia group had the highest number of additional fractures (n = 53), and even patients with normal BMD showed a notable yield (n = 36). Correlations between T-score and fracture counts were weak and not statistically significant. Conclusions: T-score can support imaging triage but should not be used as a strict threshold. STIR MRI is justified in patients with T-scores < -2.5 when clinical suspicion exists and should be considered in those with higher T-scores if CT is negative but symptoms persist. Integrating T-score into imaging protocols may reduce missed fractures and improve outcomes.