Spatial resolution improvement of 450 kV computed tomography via vertical subpixel detector shifting

Area of Science:

• Materials Science
• Imaging Technology
• Non-Destructive Testing

Background:

• High-energy X-ray sources (450 kV) often produce large focal spots, limiting spatial resolution in computed tomography (CT).
• Low spatial resolution in CT hinders the detailed analysis of fine features, particularly in industrial applications.

Purpose of the Study:

• To develop and validate a novel method for improving the spatial resolution of 450 kV CT systems.
• To enable clearer imaging of small, periodic features in additively manufactured components.

Main Methods:

• Implementation of vertical subpixel detector shifting to effectively double pixel density.
• Application of deconvolution algorithms to reconstruct an enhanced projection dataset.
• Utilizing a metal additively manufactured component with ~200 μm features for demonstration.

Main Results:

• Achieved an increase in the 10% modulation transfer function (MTF) from 3 lp/mm to 4 lp/mm.
• Demonstrated improved resolution, making previously unresolved 200 μm features clearly discernible.
• Successfully enhanced the capability of 450 kV CT for detailed inspection.

Conclusions:

• The proposed method effectively enhances spatial resolution in 450 kV CT without requiring hardware upgrades.
• This technique offers a viable solution for imaging fine details in industrial components, improving non-destructive evaluation.
• The subpixel shifting and deconvolution approach represents a significant advancement in CT imaging quality.