title: Measurement of Myocardial Extracellular Volume Fraction From Iodine Density Images Using Single-Source, Dual-Energy Computed Tomography: A Feasibility Study.
abstract: OBJECTIVE
  The aims of this study were to develop and validate an iodine density method for the quantification of myocardial extracellular volume (ECV) fraction using single-source, dual-energy computed tomography.
  
  
  METHODS
  Extracellular volume measurements were carried out in 40 subjects (20 patients with heart failure, 20 control subjects) using single-source, dual-energy computed tomography. Subtraction-derived ECVs (subECVs) were computed by subtracting precontrast from delayed images. Iodine density-derived ECVs (iECVs) were calculated from iodine density images obtained from delayed images. Iodine density-derived ECVs were compared with reference subECVs.
  
  
  RESULTS
  A strong correlation (r = 0.896, P < 0.0001) and a small bias (-0.06%) were determined between subECV and iECV with high interobserver concordances (0.915 and 0.906, respectively). Extracellular volume measurements in patients with heart failure were higher in both subECV and iECV compared with control subjects (34.6% [SD, 5.0%] vs 29.5% [SD, 3.6%], P = 0.001, for subECV; 34.9% [SD, 4.5%] vs 29.2% [SD, 2.6%], P < 0.0001, for iECV).
  
  
  CONCLUSIONS
  Extracellular volume analysis using iodine density is a useful tool for the noninvasive quantification of ECV in myocardial diseases.
authors.affiliation: From the *Division of Radiology, Department of Pathophysiological Therapeutic Science, and †Division of Molecular Medicine and Therapeutics, Department of Multidisciplinary Internal Medicine, Tottori University Faculty of Medicine; and ‡Department of Clinical Radiology, Tottori University Hospital, Yonago, Japan.
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Ohta
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kitao
authors.forename: Tomomi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Natsuko
authors.initials: N
authors.lastname: Mukai
authors.forename: Junichi
authors.initials: J
authors.lastname: Kishimoto
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Toshihide
authors.initials: T
authors.lastname: Ogawa
mesh_terms: D000368:Aged; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006331:Heart Diseases / Q000000981:diagnostic imaging*; D006801:Humans; D007455:Iodine; D008297:Male; D009206:Myocardium; D011856:Radiographic Image Enhancement; D015900:Radiography, Dual-Energy Scanned Projection; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007455:Iodine