title: The detection of coronary stiffness in cardiac allografts using MR imaging.
abstract: OBJECTIVE
  To test the hypothesis that biomechanical changes are quantitatively related to morphological features of coronary arteries in heart transplant (HTx) recipients.
  
  
  METHODS
  With IRB approval, three-dimensional (3D) magnetic resonance (MR) angiography and two-dimensional (2D) black-blood stead-state free precession (SSFP) MR imaging were performed to image coronary arteries of 36 HTx patients. Contours of coronary wall were manually drawn. For each coronary segment, coronary wall thickness, wall area, lumen area (in systole and diastole) were acquired. Coronary distensibility index (CDI) and the percent of the coronary wall occupying the vessel area (PWOV) were calculated.
  
  
  RESULTS
  There are totally 98 coronary segments eligible for quantitative analysis from 27 HTx patients. The CDI is 4.90 ± 2.44 mmHg(-1). The mean wall thickness is 1.49 ± 0.24 mm and the PWOV is 74.6% ± 7.5%. CDI has moderate correlations with wall thickness (r=-0.531, P<0.001) and with PWOV (R=-0.435, P<0.001).
  
  
  CONCLUSIONS
  Detected with coronary MR imaging, CDI is quantitatively correlated with the morphological features of the coronary artery in HTx patients. Coronary stiffness has the potential to become an alternative imaging biomarker for the quantitative assessment of the status of cardiac allografts.
authors.affiliation: Department of Radiology, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL 60611, United States. Electronic address: kai-lin@northwestern.edu.
authors.forename: Kai
authors.initials: K
authors.lastname: Lin
authors.affiliation: Department of Preventive Medicine, Northwestern University, 680 N Lake Shore Drive, Suite 1400, Chicago, IL 60611, United States.
authors.forename: Donald M
authors.initials: DM
authors.lastname: Lloyd-Jones
authors.affiliation: Department of Radiology, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL 60611, United States.
authors.forename: Kirsi
authors.initials: K
authors.lastname: Taimen
authors.affiliation: Department of Radiology, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL 60611, United States.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Cardiovascular MR R&D, Siemens Healthcare, 737 N Michigan Avenue, Suite 1600, Chicago, IL 60611, United States.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Bi
authors.affiliation: Department of Radiology, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL 60611, United States.
authors.forename: Debiao
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Radiology, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL 60611, United States.
authors.forename: James C
authors.initials: JC
authors.lastname: Carr
mesh_terms: D001696:Biomechanical Phenomena; D003331:Coronary Vessels / Q000503:physiopathology*; D005260:Female; D016027:Heart Transplantation; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D059289:Vascular Stiffness / Q000502:physiology*
keywords: Coronary stiffness; Heart transplantation; Magnetic resonance imaging