Metal artifact reduction for CT-based luggage screening.

Area of Science:

• Computed Tomography (CT) Imaging
• Aviation Security Screening
• Medical Imaging Techniques

Background:

• Checked luggage screening uses CT scanning, but metal objects cause artifacts that degrade image quality.
• Existing metal artifact reduction (MAR) methods often require material identification or use outlier rejection.
• These limitations hinder effective MAR in practical applications like aviation security.

Purpose of the Study:

• To enhance and evaluate a previously developed MAR method for CT imaging.
• The improved method aims to reduce artifacts without prior knowledge of scanned materials.
• Focus on effective MAR for luggage scans with diverse and substantial metal content.

Main Methods:

• Detailed optimization de-emphasizes metal projections, incorporating beam hardening and scatter constraints.
• Artifacts are isolated and reduced in an intermediate image.
• The processed image is then utilized in a sinogram replacement technique for final artifact reduction.

Main Results:

• Significant reduction in metal artifacts observed in test luggage images.
• The method effectively handled multiple and large metal objects.
• Image structure and resolution were largely preserved post-artifact reduction.

Conclusions:

• The developed MAR method demonstrates superior performance compared to existing techniques.
• It operates without making assumptions about image content or discarding metal projections.
• This approach offers a robust solution for metal artifact reduction in CT imaging.