Correction of X-ray scattering in energy-resolved computed tomography imaging of 20-cm-diameter phantom. Issue 4 (3rd April 2022)

• Record Type: Journal Article
• Authors: Kuniwake, Hiroya; Nishikawa, Junichiro; Kanno, Ikuo; Shimomura, Kohei
• Is Part Of: Journal of nuclear science and technology. Volume 59:Issue 4(2022)
• Page Start: 510
• Page End: 517
• Publication Date: 2022-04-03
• Subjects: X-ray -- current measurement -- computed tomography -- energy-resolved -- scattered X-ray correction; Nuclear engineering -- Periodicals; Nuclear physics -- Periodicals; Nuclear energy -- Periodicals; 621.4805
• DOI: 10.1080/00223131.2021.1982786
• Languages: English
• ISSNs: 0022-3131

Abstract

ABSTRACT: In computed tomography (CT) of human-sized subjects, scattered X-rays distort CT images, which medical doctors then use to diagnose diseases. X-ray scattering causes further difficulties in energy-resolved CT (ER-CT) because the scattered X-rays affect the electric currents used to calculate X-ray energy spectrum. Conventional strategies for correcting X-ray scattering have undesirable requirements such as increased dose exposure, lengthy calculations, and large amounts of input data. In this paper, we propose a scattered X-ray correction method that combines experiment and calculation. Electric current induced by both primary and scattered X-rays was measured for a 'scatter-correction phantom' made of acrylic, which had the same dimensions with the one having six other resins. The contribution of the primary X-rays to the electric current was estimated by a simple calculation. The scattered X-ray contribution in the electric current was given as the difference between the experimental and the calculated values. Effective atomic numbers and electron number densities of seven resins obtained by ER-CT with and without scatter correction are compared. With the correction of X-ray scattering, excellent proportionalities between estimated and theoretical values are obtained for the effective atomic number and electron number density.