Geometric parameters sensitivity evaluation based on projection trajectories for X-ray cone-beam computed...

Area of Science:

• Medical Imaging
• Non-Destructive Testing
• Geometric Metrology

Background:

• X-ray cone-beam computed laminography (CL) is essential for imaging large flat objects beyond the scope of computed tomography (CT).
• Geometric correction in CL systems is complex due to factors like axis tilt rotation angles.
• Evaluating geometric parameter sensitivity is vital for accurate CL system calibration.

Purpose of the Study:

• To objectively and comprehensively assess the sensitivity of CL geometric parameters.
• To establish a reliable method for evaluating geometric parameter sensitivity in CL systems.

Main Methods:

• Derivation of projection trajectory formulas based on CL system geometry.
• Introduction of the Minimum Deviation Unit (MDU) as a sensitivity evaluation index.
• Analysis of the impact of axis tilt rotation and magnification on MDU.

Main Results:

• At low magnification, parameters η, u0, and v0 require precise calibration (MDU < 1° or mm) to prevent geometric artifacts.
• Parameter sensitivity increases with magnification.
• All CL parameters become highly sensitive at magnification powers exceeding 10.

Conclusions:

• The developed MDU method provides a quantitative measure for CL geometric parameter sensitivity.
• Findings offer crucial guidance for future parameter calibration in CL systems.