K-Edge imaging using a clinical dual-source photon-counting CT system

Area of Science:

• Medical Imaging
• Materials Science

Background:

• Photon-counting CT (PCCT) facilitates K-edge imaging, a multi-material decomposition technique.
• K-edge imaging applications, such as dual-contrast imaging, may reduce radiation dose and motion artifacts.

Purpose of the Study:

• To assess the feasibility and performance of K-edge imaging for iodine (I) and gadolinium (Gd) using a clinical PCCT system.

Main Methods:

• A dual-source clinical PCCT scanner with four energy thresholds was used.
• Phantoms with single and dual contrast solutions (I and Gd) were scanned at various concentrations and doses.
• Multi-material decomposition was performed using an image-domain algorithm, with quantitative accuracy assessed via Bland-Altman analysis and CNR.

Main Results:

• Successful K-edge imaging and accurate decomposition of I and Gd were achieved across different concentrations, compositions, and doses.
• Radiation dose, concentration, and solution composition significantly influenced quantitative bias.
• Contrast-to-noise ratio (CNR) correlated linearly with concentration and moderately with dose, with higher values for Gd than I.

Conclusions:

• K-edge imaging is feasible on a clinical PCCT system, enabling accurate simultaneous decomposition of I and Gd.
• These findings support the clinical use of K-edge imaging for advanced dual-contrast and molecular imaging.