Producing micro-finite element models from real-time clinical CT scanners: calibration, validation and material...

Area of Science:

• Biomechanics
• Medical Imaging
• Computational Modeling

Background:

• Patient-specific finite element (FE) models enhance surgical planning and stress analysis.
• Clinical scanners offer in-vivo safety but lower resolution than in-vitro methods.
• Bridging the gap between clinical scans and reliable FE models presents technical challenges.

Purpose of the Study:

• To validate a workflow for creating patient-specific finite element models from clinical CT scans.
• To identify optimal methods for converting voxel data to material properties for FE analysis.
• To assess the biomechanical accuracy of models derived from weight-bearing CT data.

Main Methods:

• Sheep vertebrae were scanned using a high-resolution clinical standing CT scanner (300-micron resolution).
• Geometric data was used to generate FE models in Abaqus/CAE.
• Models were validated against experimental compression loading, comparing various material property conversion equations.

Main Results:

• The accuracy of FE models depended significantly on the chosen material conversion equation.
• Two specific equations from the literature provided the best fit with experimental results.
• Challenges included data conversion, achieving convergence, and refining boundary conditions.

Conclusions:

• A validated workflow for generating biomechanically consistent FE models from clinical, weight-bearing CT scans was established.
• Selecting appropriate material conversion equations is crucial for reliable patient-specific modeling.
• This approach streamlines the creation of accessible, post-scan computational models for clinical applications.