Finite Element Analysis-Based Vertebral Bone Strength Prediction Using MDCT Data: How Low Can We Go?

Area of Science:

• Medical Imaging
• Radiology
• Biomechanical Engineering

Background:

• Assessing vertebral bone strength is crucial for fracture risk evaluation.
• Multi-detector computed tomography (MDCT) is used for bone strength prediction.
• Reducing radiation dose in MDCT is essential for patient safety.

Purpose of the Study:

• To evaluate the impact of dose reduction techniques (tube current reduction and sparse sampling) on vertebral bone strength prediction using finite element (FE) analysis.
• To determine the feasibility of maintaining accuracy in fracture risk assessment with lower radiation doses.

Main Methods:

• MDCT data from 12 subjects' lumbar vertebrae were used.
• Dose reduction was achieved through tube current reduction (50%, 75%, 90%) and sparse sampling (50%, 75%, 90%).
• Subject-specific non-linear FE analyses were performed on 3D models to predict bone strength, comparing results against high-dose scans.

Main Results:

• Up to 90% dose reduction via sparse sampling showed minimal impact on FE-predicted failure loads (R²=0.86, RMSCV=11.30%).
• Up to 50% dose reduction via tube current reduction maintained prediction accuracy (R²=0.96, RMSCV=12.06%).
• Higher dose reductions (>50%) with tube current reduction significantly affected failure load prediction accuracy (R²=0.43, RMSCV=54.18% at 90%).

Conclusions:

• A 50% radiation dose reduction using tube current reduction or a 90% reduction using sparse sampling is viable for vertebral bone strength prediction.
• Sparse sampling demonstrates superior performance compared to tube current reduction for generating images suitable for FE-based bone strength prediction.
• These findings support the use of optimized, lower-dose MDCT protocols for accurate fracture risk assessment.