MRI-based vertebral bone quality score as a novel bone status marker of patients with adolescent idiopathic scoliosis

Abstract

Purpose: To evaluate the application of MRI-based L1-L4 vertebral bone quality (VBQ) score in assessing bone mineral density (BMD) for patients with adolescent idiopathic scoliosis (AIS). Methods: We reviewed the data of AIS patients between January 2021 and October 2023 with MRI, whole-spine plain radiographs, quantitative computed tomography (QCT) and general information. VBQ L1-L4 score was calculated using T1-weighted MRI. Univariate analysis was applied to present the differences between variables of patients with normal group (Z-score>-2.0) and low-BMD group (Z-score≤-2.0). The correlation between the VBQ score and QCT Z-score was analyzed with Pearson correlation test. A multivariate logistic regression model was used to determine the independent factors related to low BMD. Receiver operating characteristic curve (ROC) was drawn to analyze the diagnostic performance of VBQ L1-L4 score in distinguishing low BMD. Results: A total of 136 AIS patients (mean age was 14.84±2.10 years) were included, of which 41 had low BMD. The low-BMD group had a significantly higher VBQL1-L4 score than that in normal group (3.48±0.85 vs 2.62±0.62, P< 0.001). The VBQL1-L4 score was significantly negative correlated with QCT Z score (r = − 0.454, P< 0.001). On multivariate analysis, VBQL1-L4 score was independently associated with low BMD (OR: 4.134, 95% CI: 2.136–8.000, P<0.001). The area under the ROC curve indicated that the diagnostic accuracy of the VBQL1-L4 score for predicting low BMD was 81%. A sensitivity of 65.9% with a specificity of 88.4% could be achieved for distinguishing low BMD by setting the VBQL1-L4 score cutoff as 3.18. Conclusions: The novel VBQL1-L4 score was a promising tool in distinguishing low BMD in patients with AIS and could be useful as opportunistic assessment for screening and complementary evaluation to QCT before surgery.