Author: Mohammed Alzaabi, Abderaouf Behouch, Nabil Maalej, Aamir Raja, Briya Tariq 👨🔬
Affiliation: Khalifa University 🌍
Purpose: Spectral Photon Counting CT (SPCCT) has emerged as a transformative technology in CT imaging capable of producing images from distinct energy windows, allowing improved material characterization and quantitative imaging. We developed a modified Rutherford method in this study to determine the effective atomic number (Zeff) and electron density (ED) of materials and tissues using SPCCT imaging.
Methods: We use the SPCCT images to obtain the linear attenuation coefficients (LAC) from four different energy windows (40-50, 50-60, 60-79, 79-115 keV) which are calibrated against the theoretical LACs. Using the calibrated LACs and the modified Rutherford method we determine the Zeff and ED values for the QRM phantom materials inserts including hydroxyapatite (1200 and 800 mg), iodine solutions (5 and 10 mg/ml), liver, muscle, and adipose tissue mimicking materials.
Results: The results demonstrated high accuracy. with a mean percentage error for ED and Zeff of 2.35% and 5.29%, respectively, for all used materials. This demonstrates the accuracy of SPCCT in material characterization and quantitative analysis.
Conclusion: This study highlights the potential of SPCCT to perform spectral analysis and accurate material characterization from a single scan with the potential of improving diagnostic and therapeutic outcomes. Further improvements, such as optimizing energy windows and refining the mathematical formulation for spectral CT will further enhance the accuracy of SPCCT in material analysis and quantitative imaging.