title: Interstitial myocardial fibrosis assessed as extracellular volume fraction with low-radiation-dose cardiac CT.
abstract: OBJECTIVE
  To develop a cardiac computed tomographic (CT) method with which to determine extracellular volume (ECV) fraction, with cardiac magnetic resonance (MR) imaging as the reference standard.
  
  
  METHODS
  Study participants provided written informed consent to participate in this institutional review board-approved study. ECV was measured in healthy subjects and patients with heart failure by using cardiac CT and cardiac MR imaging. Paired Student t test, linear regression analysis, and Pearson correlation analysis were used to determine the relationship between cardiac CT and MR imaging ECV values and clinical parameters.
  
  
  RESULTS
  Twenty-four subjects were studied. There was good correlation between myocardial ECV measured at cardiac MR imaging and that measured at cardiac CT (r = 0.82, P < .001). As expected, ECV was higher in patients with heart failure than in healthy control subjects for both cardiac CT and cardiac MR imaging (P = .03, respectively). For both cardiac MR imaging and cardiac CT, ECV was positively associated with end diastolic and end systolic volume and inversely related to ejection fraction (P < .05 for all). Mean radiation dose was 1.98 mSv ± 0.16 (standard deviation) for each cardiac CT acquisition.
  
  
  CONCLUSIONS
  ECV at cardiac CT and that at cardiac MR imaging showed good correlation, suggesting the potential for myocardial tissue characterization with cardiac CT.
authors: Department of Radiology and Imaging Sciences, National Institutes of Health Clinical Center, 10 Center Dr, Bldg 10, Room 1C355, Bethesda, MD 20892-1182, USA.
authors: Marcelo Souto
authors: MS
authors: Nacif
authors: Nadine
authors: N
authors: Kawel
authors: Jason J
authors: JJ
authors: Lee
authors: Xinjian
authors: X
authors: Chen
authors: Jianhua
authors: J
authors: Yao
authors: Anna
authors: A
authors: Zavodni
authors: Christopher T
authors: CT
authors: Sibley
authors: João A C
authors: JA
authors: Lima
authors: Songtao
authors: S
authors: Liu
authors: David A
authors: DA
authors: Bluemke
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055424:Cardiac-Gated Imaging Techniques; D003287:Contrast Media; D004719:Endomyocardial Fibrosis / Q000000981:diagnostic imaging*; D005260:Female; D005355:Fibrosis; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media