MRI-based vertebral bone quality score: relationship with age and reproducibility

Area of Science:

• Radiology
• Orthopedics
• Bone Health

Background:

• Vertebral bone quality (VBQ) score is an opportunistic measure of bone mineral density (BMD) using routine preoperative MRI in spine surgery.
• VBQ score is known to correlate with age and demonstrate reproducibility across serial scans.
• However, extrinsic factors like MRI machine and protocol can affect VBQ scores, necessitating standardization.

Purpose of the Study:

• To determine if VBQ score increases with patient age.
• To assess the consistency of VBQ scores across serial MRI studies conducted within a 3-month interval.

Main Methods:

• Retrospective analysis of 136 patients (age 20-69) with serial T1-weighted lumbar MRI within 3 months.
• VBQ(L1-4) and VBQ(L1) scores calculated using signal intensity ratios (vertebrae to CSF).
• Regression analysis for age correlation and coefficient of variation (CV) for reproducibility.

Main Results:

• VBQ(L1-4) score positively correlated with age when controlling for MRI relaxation/echo time.
• Excellent reproducibility of VBQ(L1-4) scores across serial MRIs (CV = 0.169).
• High agreement (ICC > 0.9) between VBQ(L1) and VBQ(L1-4) scores.

Conclusions:

• Age and MRI technical factors impact VBQ scores, requiring consideration for BMD estimation.
• VBQ score's positive correlation with age and excellent reproducibility support its use in estimating BMD.
• VBQ(L1) score serves as a reliable alternative to VBQ(L1-4) for assessing bone quality.