title: Quantitative myocardial perfusion with stress dual-energy CT: iodine concentration differences between normal and ischemic or necrotic myocardium. Initial experience.
abstract: OBJECTIVE
  To determine whether the quantification of iodine with stress dual-energy computed tomography (DECT-S) allows for the discrimination between a normal and an ischemic or necrotic myocardium using magnetic resonance (MR) as a reference.
  
  
  METHODS
  This retrospective study was approved by the institutional review board, with waiver of informed consent. Thirty-six cardiac MR and DECT-S images from patients with suspected coronary artery disease were evaluated. Perfusion defects were visually determined, and myocardial iodine concentration was calculated by two observers using DECT colour-coded iodine maps. Iodine concentration differences were calculated using parametric tests. Receiver operating characteristic (ROC) curve analysis was conducted to estimate the optimal iodine concentration threshold for discriminating pathologic myocardium.
  
  
  RESULTS
  In total, 576 cardiac segments were evaluated. There were differences in mean iodine concentration (p < 0.001) between normal (2.56 ± 0.66 mg/mL), ischemic (1.98 ± 0.36 mg/dL) and infarcted segments (1.35 ± 0.57 mg/mL). A myocardium iodine concentration of 2.1 mg/mL represented the optimal threshold to discriminate between normal and pathologic myocardium (sensitivity 75 %, specificity 73.6 %, area under the curve 0.806). Excellent agreement was found in measured myocardium iodine concentration (intraclass correlation coefficient 0.814).
  
  
  CONCLUSIONS
  Cardiac DECT-S with iodine quantification may be useful to differentiate healthy and ischemic or necrotic myocardium.
  
  
  CONCLUSIONS
  • DECT-S allows for determination of myocardial iodine concentration as a quantitative perfusion parameter. • A high interobserver correlation exists in measuring myocardial iodine concentration with DECT-S. • Myocardial iodine concentration may be useful in the assessment of patients with CAD.
authors.affiliation: Radiology Department, Povisa Hospital, Salamanca, 36211, Vigo, Pontevedra, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Delgado Sánchez-Gracián
authors.affiliation: Radiology Department, Povisa Hospital, Salamanca, 36211, Vigo, Pontevedra, Spain. roqueoca@hotmail.com.
authors.forename: Roque
authors.initials: R
authors.lastname: Oca Pernas
authors.affiliation: Radiology Department, Povisa Hospital, Salamanca, 36211, Vigo, Pontevedra, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Trinidad López
authors.affiliation: Radiology Department, Povisa Hospital, Salamanca, 36211, Vigo, Pontevedra, Spain.
authors.forename: Eloísa
authors.initials: E
authors.lastname: Santos Armentia
authors.affiliation: Vigo University and Povisa Hospital, Vigo, Pontevedra, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Vaamonde Liste
authors.affiliation: Radiology Department, Povisa Hospital, Salamanca, 36211, Vigo, Pontevedra, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Vázquez Caamaño
authors.affiliation: Radiology Department, Povisa Hospital, Salamanca, 36211, Vigo, Pontevedra, Spain.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Tardáguila de la Fuente
mesh_terms: D005260:Female; D006801:Humans; D007455:Iodine / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D012372:ROC Curve; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D007455:Iodine
keywords: Iodine maps; Magnetic resonance imaging; Myocardial perfusion imaging; Tomography; X-ray computed