Background: Computed tomography Hounsfield unit (HU) and magnetic resonance imaging (MRI)-based vertebral bone quality (VBQ) score are both alternative tool to the dual energy x-ray absorptiometry(DEXA) scan T-score to quantify the bone quality. However, it is not known which method more accurately reflects vertebral bone mineral density.
Purpose: To evaluate the best method for evaluating vertebral bone mineral density in patients undergoing lumbar spine surgery.
Methods: Eighty-five patients who had at most two vertebrae with severe degeneration at L1–L4 were retrospectively reviewed.HU value was measured by axial CT image, VBQ score was calculated by T1-weighted lumbar MRI image, and L1-L4 T-score and bone mineral density (BMD) were measured by DEXA.The correlation of the vertebral HU value and VBQ score to the T-score was analyzed.
Results: There were 52 female and 33 male patients. The average age was 57.18±9.65 years . HU values had a positive correlation with BMD and T-score. The correlation coefficients between HU and T-score was 0.751(<0.001) for L1; 0.699(<0.001) for L2; 0.618(<0.001) for L3; 0.543(<0.001) for L4; and 0.677(<0.001) for L1-4.However,VBQ score had a negative correlation with BMD and T-score. The correlation coefficients between VBQ score and T-score was -0.231(<0.05) for L1; -0.246(<0.05) for L2; -0.268(<0.05) for L3; -0.252(<0.05) for L4; and -0.346(<0.01) for L1-4. The correlation coefficients of HU value at L1–L4 were higher than the correlation coefficients of VBQ score .
Conclusions: HU value was a better predictor of vertebral bone mineral density than VBQ score in patients with lumbar degenerative disease.