A novel modified VBQ Score，Correlation with the Vertebral Bone Quality Score, independently assessing for bone quality in patients with Osteoporosis Vertebral Fracture
Authors: Wu Yuxiang , Guo Jinfa , Zhang Houjun , Wang Qiang , Xu Lin , Mu Xiaohong , Wen Tianlin , Lin Huanan , Ke Xun , Chen Haipeng , Xu Leqin , Ma Weiwei , Li Bushuang , Zhang Qiwei 
Published: October 2024

Background :The VBQ Score, a formula based on magnetic resonance imaging (MRI) parameters, facilitates the assessment of bone quality in patients with osteoporotic vertebral fractures, offering substantial clinical convenience. However, the formula necessitates lumbar MRI imaging for data collection and evaluation, leading to practical challenges in clinical scenarios. Specifically, in the case of a thoracic vertebral fracture, additional lumbar spine MRI is necessary to obtain pertinent data, or when incomplete lumbar spine MRI images exist, the measurement of relevant data becomes challenging.
Purpose: This study introduces a m-VBQ score and compares it with the standard VBQ score, investigating the feasibility and accuracy of the improved VBQ score for evaluating bone quality.
Methods: A retrospective study was conducted, involving adult patients from January 2017 to December 2022. The study included a patient sample comprising 103 individuals with osteoporotic vertebral fractures (OVF) and 103 without OVF. METHODS: The collected data encompassed non-contrast T1-weighted MRI, DEXA, and demographic information from both the fracture group and the non-fracture group patients. The m-VBQ score was established by selecting the vertebral scoring site, which could be either the vertebral body of a single-segment fractured vertebra or the vertebral body of a single-segment non-fractured vertebra. This involved calculating the median signal intensity (MSI) of the two vertebrae above and the two vertebrae below the vertebral scoring site, followed by dividing this value by the signal intensity of the cerebrospinal fluid (CSF) in the vertebra immediately below the vertebral scoring site. The differences between the two m-VBQ score groups were evaluated using the Student's t-test. Additionally, the relationship between the m-VBQ score and VBQ score was examined through Pearson correlation analysis, univariate linear regression, and intra-group correlation analysis. Binary logistic regression was utilized to investigate the association of the VBQ score, m-VBQ score, and occurrence of OVF. Receiver Operating Characteristic (ROC) analysis was performed to determine the Area Under the Curve (AUC) for both scores as predictors of OVF and osteoporosis (OP). Furthermore, subgroup analyses were conducted based on the vertebral score location, with statistical significance determined at P<0.05.
Results:There was a significant difference in m-VBQ scores between the fracture and non-fracture groups (3.88±0.86 vs. 3.07±0.59, P < 0.001). Pearson correlation analysis revealed a strong positive association between m-VBQ scores and VBQ scores (r=0.842, P<0.001). As the scoring vertebral site approached L2 from above, the Pearson correlation coefficient increased, reaching its peak at L2 (r=0.951, P<0.001) and subsequently decreasing for sites below. Linear regression analysis between m-VBQ and VBQ scores indicated that as the scoring vertebral site approaches L2 from above, the slope of the equation might increase, with the maximum slope observed at L2 (β1=0.9757), and then potentially decrease for lower sites. The consistency between VBQ scores and m-VBQ scores is excellent (ICC = 0.841). As the vertebral scoring site of the m-VBQ score progresses downward, nearing L2, the ICC coefficient potentially increases, reaching its peak at L2 (ICC = 0.950). Beyond this point, the ICC coefficient might decrease.Binary logistic regression highlighted that m-VBQ scores (OR=1.253-5.282, 95%CI:1.210-5.496, P=0.010) had a stronger significance in predicting OVF compared to VBQ scores (OR=2.579, 95%CI:1.210-5.496, P=0.014). Regarding OVF prediction, the AUC for m-VBQ was 0.776 (95%CI:0.713-0.838, P<0.001), indicating good predictive capability, similar to VBQ. For specific vertebral sites, m-VBQ's predictive ability was superior to VBQ for the T3-T11 subgroup, equivalent for the L3-L5 subgroup, and inferior for the T12, L1, and L2 subgroups. In predicting osteoporosis (OP), the AUC for m-VBQ was 0.737 (95%CI:0.669-0.805, P<0.001), suggesting a stronger predictive capacity compared to VBQ. Inter-rater reliability for m-VBQ scores among two reviewers yielded an ICC of 0.896 (95%CI 0.861-0.963, P<0.001), and intra-rater reliability resulted in an ICC of 0.81 (95% CI 0.759-0.853, P<0.001).
Conclusion:The VBQ score and the m-VBQ score, derived from the adjacent vertebrae of OVF patients, are both effective indices for assessing bone quality in OVF patients. The m-VBQ score exhibits good predictive capability for OVF and OP, closely mirroring the VBQ score's predictive power. Compared to the conventional VBQ score, we believe the m-VBQ score offers more flexibility and clinical operability while maintaining similar reliability for evaluating OP and OVF. Furthermore, it enables the assessment of bone quality in vertebrae adjacent to fractures, potentially predicting subsequent fractures in neighboring vertebrae.