Cone beam x-ray luminescence computed tomography: a feasibility study.

Area of Science:

• Medical Imaging
• Biophysics
• Computational Imaging

Background:

• X-ray luminescence computed tomography (XLCT) enables molecular imaging using X-rays.
• Previous XLCT systems used narrow beams, leading to long scan times and inefficient X-ray dose utilization.
• A need exists for faster and more efficient XLCT methods.

Purpose of the Study:

• To propose and validate a novel cone beam X-ray luminescence computed tomography (XLCT) strategy.
• To enhance X-ray dose utilization and reduce scanning time compared to previous methods.
• To describe the imaging model and reconstruction techniques for cone beam XLCT.

Main Methods:

• Employed a cone beam X-ray illumination and a charge-coupled device (CCD) camera for photon detection.
• Addressed the ill-posed nature of photon scattering using diffusion approximation and sparse regularization.
• Utilized an incomplete variables truncated conjugate gradient method and a permissible region strategy for reconstruction, incorporating X-ray attenuation effects.

Main Results:

• Simulation experiments with cylinder phantoms demonstrated the compensated method's validity, achieving reconstruction errors below 2 mm.
• Evaluated robustness and stability across varying view numbers, regularization parameters, noise levels, and optical parameter mismatches, showing minimal impact.
• Non-homogeneous phantom simulations and physical phantom experiments confirmed the method's feasibility for complex scenarios and real-world applications.

Conclusions:

• The cone beam XLCT method was validated through numerical simulations and physical experiments.
• Cone beam XLCT offers improved X-ray dose utilization and significantly reduced scanning times compared to narrow beam XLCT.
• The proposed method is demonstrated to be feasible for general cases and actual experimental conditions.