Spectral Computed Tomography: Fundamental Principles and Recent Developments

Aaron So; Savvas Nicolaou

doi:10.3348/kjr.2020.0144

Spectral Computed Tomography: Fundamental Principles and Recent Developments

Korean J Radiol. 2021 Jan;22(1):86-96. doi: 10.3348/kjr.2020.0144. Epub 2020 Sep 10.

Authors

Aaron So^{1

2}, Savvas Nicolaou^{3

4}

Affiliations

¹ Imaging Program, Lawson Health Research Institute, London, Canada.
² Department of Medical Biophysics, University of Western Ontario, London, Canada. aso@robarts.ca.
³ Department of Emergency and Trauma Imaging, Vancouver General Hospital, Vancouver, Canada.
⁴ Department of Radiology, University of British Columbia, Vancouver, Canada.

Abstract

CT is a diagnostic tool with many clinical applications. The CT voxel intensity is related to the magnitude of X-ray attenuation, which is not unique to a given material. Substances with different chemical compositions can be represented by similar voxel intensities, making the classification of different tissue types challenging. Compared to the conventional single-energy CT, spectral CT is an emerging technology offering superior material differentiation, which is achieved using the energy dependence of X-ray attenuation in any material. A specific form of spectral CT is dual-energy imaging, in which an additional X-ray attenuation measurement is obtained at a second X-ray energy. Dual-energy CT has been implemented in clinical settings with great success. This paper reviews the theoretical basis and practical implementation of spectral/dual-energy CT.

Keywords: Computed tomography; Dual energy; Spectral; X-rays.

Publication types

Review

MeSH terms

Algorithms
Humans
Image Processing, Computer-Assisted
Photons
Tomography, X-Ray Computed / instrumentation
Tomography, X-Ray Computed / methods*