Dual-Energy CT: New Horizon in Medical Imaging

Korean J Radiol. Jul-Aug 2017;18(4):555-569. doi: 10.3348/kjr.2017.18.4.555. Epub 2017 May 19.


Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector.

Keywords: CT imaging techniques; Dual-energy CT; Effective atomic number; Material decomposition; Photon-counting detector; Spectral CT; Virtual monoenergetic imaging.

Publication types

  • Review

MeSH terms

  • Gout / diagnostic imaging
  • Hodgkin Disease / diagnostic imaging
  • Humans
  • Phantoms, Imaging
  • Scoliosis / diagnostic imaging
  • Thorax / diagnostic imaging
  • Tomography, X-Ray Computed / instrumentation
  • Tomography, X-Ray Computed / methods*