Effects of dose reduction on bone strength prediction using finite element analysis

Area of Science:

• Biomedical Engineering
• Radiology
• Orthopedics

Background:

• Accurate bone strength prediction is crucial for diagnosing osteoporosis and assessing fracture risk.
• Multi-detector computed tomography (MDCT) is widely used for bone density and strength estimation.
• Concerns exist regarding the impact of reduced radiation dose on the accuracy of these estimations.

Purpose of the Study:

• To evaluate the effect of X-ray tube exposure reduction on bone strength prediction using finite-element (FE) analysis.
• To determine the optimal radiation dose for MDCT imaging while maintaining accuracy in bone strength assessment.

Main Methods:

• Eleven fresh thoracic mid-vertebrae specimens were imaged using MDCT at varying X-ray tube exposures (80, 150, 220, and 500 mAs).
• Bone mineral density (BMD) was estimated, and image quality and specimen geometry were measured.
• Finite-element analysis was performed to predict fracture load, with results compared against the highest CT dose (500 mAs) as a reference.

Main Results:

• Dose reduction showed no significant impact on FE-predicted fracture loads.
• High correlations were observed between reduced doses (80, 150, 220 mAs) and the reference dose (R² values ranging from 0.987 to 0.998, p < 0.001).
• Volume quantification remained consistent across different radiation doses, and CT radiation dose could be reduced by up to 64% without compromising strength estimates.

Conclusions:

• Substantial reduction in CT radiation dose is feasible without compromising the accuracy of bone strength prediction via FE analysis.
• Reduced CT doses can facilitate earlier diagnosis and improved monitoring of osteoporosis and associated fracture risks.
• This finding supports the optimization of CT imaging protocols for enhanced patient safety and diagnostic efficacy.