title: In vivo assessment of MR elastography-derived effective end-diastolic myocardial stiffness under different loading conditions.
abstract: OBJECTIVE
  To compare magnetic resonance elastography (MRE) effective stiffness to end-diastolic pressure at different loading conditions to demonstrate a relationship between myocardial MRE effective stiffness and end-diastolic left ventricular (LV) pressure.
  
  
  METHODS
  MRE was performed on four pigs to measure the end-diastolic effective stiffness under different loading conditions. End-diastolic pressure was increased by infusing Dextran-40 (20% of blood volume). For each infusion of Dextran-40, end-diastolic pressure was recorded and end-diastolic effective stiffness was measured using MRE. In each pig, least-square linear regression was performed to determine the correlation between end-diastolic effective stiffness and end-diastolic LV pressure.
  
  
  RESULTS
  A linear correlation was found between end-diastolic LV pressure and end-diastolic effective stiffness with R(2) ranging from 0.73-0.9. A linear correlation with R(2) = 0.26 was found between end-diastolic LV pressure and end-diastolic effective stiffness when pooling data points from all pigs.
  
  
  CONCLUSIONS
  End-diastolic effective myocardial stiffness increases linearly with end-diastolic LV pressure.
authors.affiliation: Radiology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Arunark
authors.initials: A
authors.lastname: Kolipaka
authors.forename: Kiaran P
authors.initials: KP
authors.lastname: McGee
authors.forename: Armando
authors.initials: A
authors.lastname: Manduca
authors.forename: Nandan
authors.initials: N
authors.lastname: Anavekar
authors.forename: Richard L
authors.initials: RL
authors.lastname: Ehman
authors.forename: Philip A
authors.initials: PA
authors.lastname: Araoz
mesh_terms: D000818:Animals; D001794:Blood Pressure; D003971:Diastole; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009206:Myocardium / Q000473:pathology*; D011312:Pressure; D012044:Regression Analysis; D013552:Swine; D016277:Ventricular Function, Left / Q000502:physiology