Distribution of electron density using dual-energy X-ray CT

• Published in: IEEE transactions on nuclear science Vol. 50; no. 5; pp. 1678 - 1682
• Main Authors: Tsunoo, T., Torikoshi, M., Sasaki, M., Endo, M., Yagi, N., Uesugi, K.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2003; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Atomic measurements; Atomic properties; Charge coupled devices; Charge-coupled image sensors; Computed tomography; Cross sections; Electron density; Electrons; Energy (nuclear); Image contrast; Image intensifiers; Optical imaging; Protons; Synchrotron radiation; X-ray imaging; X-rays
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2003.817331

Knowledge of electron densities for materials is important for treatment planning for proton and heavier-ion radiotherapy. In order to obtain the electron densities with high precision, we have developed dual-energy X-ray computed tomography using synchrotron radiation. Two monochromatic X-rays with different energies generated from synchrotron radiation enables tomographic imaging which produces a cross sectional image based on electron density plus an additional image based on effective atomic number. Experiments for the dual-energy X-ray CT were made on the BL20B2 beamline at SPring-8. An image intensifier system and a CCD camera were used as the 2-D detectors. The measured electron densities were agreement to within 2% of the theoretical ones. Electron density and effective atomic number provide different contrast in images. Dual-energy X-ray CT can be used for quantitative measurement of the material.