Evaluation of vertebral bone strength with a finite element method using low dose computed tomography imaging

Area of Science:

• Biomedical Engineering
• Radiology
• Computational Mechanics

Background:

• Computed tomography (CT)-based finite element analysis (FEA) is crucial for evaluating bone strength, particularly for compression fractures.
• High radiation exposure dose remains a significant concern in CT imaging.
• Reducing radiation dose without compromising diagnostic accuracy is a key challenge.

Purpose of the Study:

• To investigate the potential for radiation dose reduction in CT imaging for bone strength analysis.
• To compare the accuracy of FEA results obtained from low-dose CT images versus reference-dose CT images.
• To evaluate the effectiveness of different image reconstruction methods for dose reduction.

Main Methods:

• CT images of pig lumbar vertebrae were acquired at various low-dose settings and a reference dose.
• Images were reconstructed using filtered back-projection (FBP) and iterative reconstruction (IR) methods.
• Finite element models were created from the reconstructed images to simulate compression fractures and calculate stress intensity.

Main Results:

• Low-dose CT imaging, utilizing IR, achieved comparable compression fracture analysis results to reference-dose imaging.
• Equivalent results were obtained with approximately 40% of the standard radiographic reference doses.
• Iterative reconstruction combined with CT-based FEA proved effective for maintaining accuracy at reduced radiation doses.

Conclusions:

• The combination of iterative reconstruction and CT-based finite element analysis offers an effective strategy for significant radiation dose reduction.
• This approach allows for accurate assessment of bone strength and fracture risk with lower radiation exposure.
• The findings support the clinical translation of reduced-dose CT protocols for skeletal analysis.