A post-scan method for correcting artefacts of slow geometry changes during micro-tomographic scans

Area of Science:

• Materials Science
• Imaging Technology
• Physics

Background:

• High-magnification micro-CT imaging is challenged by geometric movements of the X-ray emission spot.
• These movements, often thermally induced, cause magnified shifts in projection images, leading to movement artifacts in reconstructed data.
• Existing methods may not fully address these dynamic artifacts in high-resolution scans.

Purpose of the Study:

• To develop and validate a novel post-scan correction technique for mitigating movement artifacts in micro-CT.
• To improve the accuracy and resolution of reconstructed images obtained from high-magnification scans.
• To enable the characterization of X-ray micro-focus spot movement during scanning.

Main Methods:

• A short reference scan with a large rotation step was performed after the main high-magnification scan.
• Image registration between the post-scan and main scan data was used to calculate X/Y pixel shifts.
• These calculated shifts were applied during the reconstruction process to correct for geometric movements.

Main Results:

• The post-scan correction method substantially reduced movement artifacts in reconstructed images.
• Image quality and resolution were significantly improved across multiple micro-CT and nano-CT scans.
• The technique allowed for the reconstruction of the spatio-temporal trajectory of the X-ray micro-focus emission spot movement.

Conclusions:

• The described post-scan correction method is effective in reducing movement artifacts in high-magnification micro-CT.
• This technique enhances the reliability and detail of nanoscale imaging.
• The method provides insights into the dynamic behavior of the X-ray source during scanning.