Extending the dynamic range of biomedical micro-computed tomography for application to geomaterials

Area of Science:

• Medical Imaging
• Materials Science
• Physics

Background:

• X-ray computed tomography (CT) provides non-destructive 3D imaging.
• Biomedical micro-CT scanners are increasingly accessible.
• CT images of dense objects suffer from beam hardening artifacts.

Purpose of the Study:

• To propose and evaluate a semi-empirical correction method for beam hardening and scatter in biomedical micro-CT.
• To improve the accuracy of CT imaging for dense and radiodense samples.

Main Methods:

• Designed and constructed novel calibration phantoms from aluminum and poly[methyl-methacrylate].
• Imaged phantoms using two biomedical micro-CT scanners.
• Applied semi-empirical linearization to projection data before image reconstruction.

Main Results:

• The proposed correction method effectively reduced beam hardening artifacts on both scanners.
• Polynomial correction using an aluminum phantom yielded the best results.
• Accurate percent-volume composition of metallic inclusions in a meteorite sample was achieved.

Conclusions:

• Semi-empirical linearization with custom calibration phantoms enables accurate measurements on radiodense samples.
• The proposed correction method enhances the reliability of biomedical micro-CT imaging for dense materials.