title: Accuracy of dual-energy computed tomography for the measurement of iodine concentration using cardiac CT protocols: validation in a phantom model.
abstract: OBJECTIVE
  To assess the accuracy of dual-energy CT (DECT) for the quantification of iodine concentrations in a thoracic phantom across various cardiac DECT protocols and simulated patient sizes.
  
  
  METHODS
  Experiments were performed on first- and second-generation dual-source CT (DSCT) systems in DECT mode using various cardiac DECT protocols. An anthropomorphic thoracic phantom was equipped with tubular inserts containing known iodine concentrations (0-20 mg/mL) in the cardiac chamber and up to two fat-equivalent rings to simulate different patient sizes. DECT-derived iodine concentrations were measured using dedicated software and compared to true concentrations. General linear regression models were used to identify predictors of measurement accuracy
  
  
  RESULTS
  Correlation between measured and true iodine concentrations (n = 72) across CT systems and protocols was excellent (R = 0.994-0.997, P < 0.0001). Mean measurement errors were 3.0 ± 7.0% and -2.9 ± 3.8% for first- and second-generation DSCT, respectively. This error increased with simulated patient size. The second-generation DSCT showed the most stable measurements across a wide range of iodine concentrations and simulated patient sizes.
  
  
  CONCLUSIONS
  Overall, DECT provides accurate measurements of iodine concentrations across cardiac CT protocols, strengthening the case for DECT-derived blood volume estimates as a surrogate of myocardial blood supply.
  
  
  CONCLUSIONS
  • Dual-energy CT provides new opportunities for quantitative assessment in cardiac imaging. • DECT can quantify myocardial iodine as a surrogate for myocardial perfusion. • DECT measurements of iodine concentrations are overall very accurate. • The accuracy of such measurements decreases as patient size increases.
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA.
authors.forename: James D
authors.initials: JD
authors.lastname: Koonce
authors.forename: Rozemarijn
authors.initials: R
authors.lastname: Vliegenthart
authors.forename: U Joseph
authors.initials: UJ
authors.lastname: Schoepf
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schmidt
authors.forename: Amy E
authors.initials: AE
authors.lastname: Wahlquist
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Nietert
authors.forename: Gorka
authors.initials: G
authors.lastname: Bastarrika
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Flohr
authors.forename: Felix G
authors.initials: FG
authors.lastname: Meinel
mesh_terms: D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007455:Iodine / Q000493:pharmacokinetics; D009206:Myocardium / Q000378:metabolism*; D019047:Phantoms, Imaging; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012984:Software
chemical_list: D007455:Iodine