MRI ‐Based Inter‐Vertebral Signal Concordance Index Is a Risk Factor of Osteoporotic Vertebral Compression Fracture: A Novel Index Inspired by Entropy

Objective MRI‐derived vertebral bone quality (VBQ) score predicts osteoporotic vertebral compression fracture (OVCF) in a fat‐dependent way. This retrospective study aimed to evaluate the predictive potential of inter‐vertebral signal concordance index (ISCI), derived by MRI in a fat‐independent way, as a novel factor for assessing the risk of OVCF. Methods Patients who suffered OVCF (OVCF group) and lumbar degenerative diseases (non‐OVCF group) between January 2022 and July 2024 were included. The ISCI was calculated from the MRI signal intensity of the L1–L4 vertebrae, measured from the lumbar T1‐weighted, T2‐weighted, and short tau inversion recovery (STIR)‐weighted sequences. The demographic data, including sex, age, body mass index (BMI), and medical history, were recorded. The ISCIs of the OVCF and non‐OVCF groups were additionally compared. Inter‐group comparisons were performed using the rank‐sum, chi‐square, or median test, as appropriate. Risk factors were identified by logistic regression, and correlations were assessed using Spearman's correlation coefficient. Results A total of 448 patients were included in this study. The T1‐ISCIs, T2‐ISCIs, and STIR‐ISCIs of the OVCF group were higher than those of the non‐OVCF cohort (13.18 vs. 9.90, 14.69 vs. 10.68, and 19.31 vs. 15.67, respectively, all p < 0.001). Comparative analysis of the ISCIs across the subgroups categorized by sex and age revealed that the T1‐ISCIs, T2‐ISCIs, and STIR‐ISCIs were higher in the OVCF group. Additionally, there were no significant differences in the ISCIs across fresh, old, and fresh + old fracture type subgroups. The results of multivariate logistic regression analysis revealed that the STIR‐ISCI (odds ratio (OR) = 1.025, p = 0.013) could serve an independent predictive factor for assessing the risk of OVCF. Conclusions The study evaluated a novel index for predicting the risk of OVCF. The T1‐ISCI and STIR‐ISCI could serve as potential predictive factors for evaluating the risk of OVCF in clinical practice.