Evaluating the dual-energy iterative reconstruction algorithm (DIRA) for accurate CT number determination in DECT...

Area of Science:

• Medical Physics
• Radiology
• Image Reconstruction

Background:

• Accurate computed tomography (CT) numbers from dual-energy CT (DECT) are crucial for applications like radiation treatment planning.
• Beam-hardening artifacts can affect CT number accuracy.

Purpose of the Study:

• To evaluate the feasibility of applying the dual-energy iterative reconstruction algorithm (DIRA) to experimental DECT data.
• To assess DIRA's ability to generate accurate, artifact-free monoenergetic images.

Main Methods:

• DIRA was adapted for experimental data by removing the patient table, modeling the bow-tie filter, and applying inverse water beam-hardening correction.
• Axial scans of polymethyl methacrylate phantoms with material inserts were acquired using a clinical Siemens SOMATOM Force scanner.

Main Results:

• DIRA achieved CT numbers closely matching tabulated values by the sixth iteration.
• The algorithm demonstrated strong performance on both a cylindrical phantom and an anthropomorphic head phantom (CIRS model 731-HN).

Conclusions:

• DIRA is feasible for experimental DECT data, producing accurate CT numbers.
• This algorithm shows potential for improving precision in radiation treatment planning and other DECT applications.