A correction method for dual energy liquid CT image reconstruction with metallic containers

Area of Science:

• Medical Imaging
• Materials Science
• Security Technology

Background:

• Dual energy computed tomography (DECT) is utilized for material discrimination in security inspections.
• Metallic containers in liquid inspection systems introduce partial volume effects (PVE), causing significant deviations in effective atomic number images.
• These deviations hinder reliable material discrimination and can lead to false detection results.

Purpose of the Study:

• To propose and validate a projection splitting method to mitigate partial volume effects (PVE) in dual energy liquid inspection.
• To improve the accuracy of effective atomic number (Zeff) imaging for reliable material discrimination in the presence of metallic containers.

Main Methods:

• A projection splitting method is introduced, requiring a prior projection of the empty container.
• Dual energy decomposition is used to calculate photoelectric and Compton coefficient integrals.
• Integrals are split by subtracting the empty container's contribution, isolating the liquid's data and removing PVE-induced errors.

Main Results:

• The projection splitting method effectively removes the influence of metallic containers on the effective atomic number (Zeff) images.
• Reconstructed images accurately represent the liquid's interior, free from container-related artifacts.
• Experimental validation in a real liquid inspection system demonstrates significant improvement in Zeff accuracy.

Conclusions:

• The proposed projection splitting method successfully combats PVE in dual energy liquid inspection systems.
• Enhanced accuracy in effective atomic number (Zeff) imaging facilitates more reliable material identification.
• This technique offers a robust solution for detecting contraband liquids within metallic containers.