title: Quantitative myocardial perfusion imaging using rapid kVp switch dual-energy CT: preliminary experience.
abstract: BACKGROUND
  Quantitative myocardial CT perfusion (CTP) is susceptible to beam-hardening (BH) artifact from conventional single-energy (kVp) CT (SECT) scanning, which can mimic perfusion deficits.
  
  
  OBJECTIVE
  We evaluated the minimization of BH artifact with dual-energy (kVp) CT (DECT) generated monochromatic CT images to improve perfusion estimates.
  
  
  METHODS
  We investigated the performance of DECT with a scanner capable of rapid kVp switching with respect to (1) BH artifact in a myocardium phantom model comparing SECT with image-based DECT and projection-based DECT, (2) optimal imaging parameters for measuring iodine concentration at high contrast-to-noise ratio in a tissue characterization phantom model, and (3) the feasibility of a dynamic time-resolved scan protocol with the projection-based DECT technique to measure myocardial perfusion in normal (nonischemic) porcine.
  
  
  RESULTS
  In a myocardium phantom model, projection-based DECT 70 keV was better able to minimize the difference in the attenuation of the myocardium (19.9 HU) between having and not having contrast in the heart chambers in comparison to SECT using 80 kVp (30.4 HU) or 140 kVp ( 23.3 HU) and image-based DECT 70 keV (27.5 HU). Further, projection-based DECT 70 keV achieved the highest contrast-to-noise ratio (3.0), which exceeded that from imaged-based DECT 70 keV (2.0), 140 kVp SECT (1.3), and 80 kVp SECT (2.9). In 5 normal pigs, projection-based DECT at 70 keV provided a more uniform perfusion estimate than SECT.
  
  
  CONCLUSIONS
  By effectively reducing BH artifact, projection-based DECT may permit improved quantitative myocardial CTP compared with the conventional SECT technique.
authors.affiliation: Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, ON N6A 5K8, Canada. aso@imaging.robarts.ca
authors.forename: Aaron
authors.initials: A
authors.lastname: So
authors.forename: Ting-Yim
authors.initials: TY
authors.lastname: Lee
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Imai
authors.forename: Suresh
authors.initials: S
authors.lastname: Narayanan
authors.forename: Jiang
authors.initials: J
authors.lastname: Hsieh
authors.forename: John
authors.initials: J
authors.lastname: Kramer
authors.forename: Karen
authors.initials: K
authors.lastname: Procknow
authors.forename: Jonathon
authors.initials: J
authors.lastname: Leipsic
authors.forename: Troy
authors.initials: T
authors.lastname: Labounty
authors.forename: James
authors.initials: J
authors.lastname: Min
mesh_terms: D000818:Animals; D016477:Artifacts; D003326:Coronary Circulation; D005240:Feasibility Studies; D005260:Female; D006439:Hemodynamics; D023421:Models, Animal; D055414:Myocardial Perfusion Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D011237:Predictive Value of Tests; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000295:instrumentation