title: In vivo quantification of myocardial stiffness in hypertensive porcine hearts using MR elastography.
abstract: To determine alteration in left ventricular (LV) myocardial stiffness (MS) with hypertension (HTN). Cardiac MR elastography (MRE) was used to estimate MS in HTN induced pigs and MRE-derived MS measurements were compared against LV pressure, thickness and circumferential strain.
  
  
  
  Renal-wrapping surgery was performed to induce HTN in eight pigs. LV catheterization (to measure pressure) and cardiac MRI (1.5 Tesla; gradient echo-MRE and tagging) was performed pre-surgery at baseline (Bx), and post-surgery at month 1 (M1) and month 2 (M2). Images were analyzed to estimate LV-MS, thickness, and circumferential strain across the cardiac cycle. The associations between end-diastolic (ED) and end-systolic (ES) MS and (i) mean LV pressure; (ii) ED and ES thickness, respectively; and (iii) circumferential strain were evaluated using Spearman's correlation method.
  
  
  
  From Bx to M2, mean pressure, MRE-derived stiffness, and thickness increased while circumferential strain decreased significantly (slope test, P ≤ 0.05). Both ED and ES MS had significant positive correlation with (i) mean pressure (ED MS: ρ = 0.56; P = 0.005 and ES MS: ρ = 0.45; P = 0.03); (ii) ED thickness ( ρ = 0.73; P < 0.0001) and ES thickness ( ρ = 0.84; P < 0.0001), respectively; but demonstrated a negative trend with circumferential strain (ED MS: ρ = 0.31 and ES MS: ρ = 0.37).
  
  
  
  This study demonstrated that, in a HTN porcine model, MRE-derived MS increased with increase in pressure and thickness.
  
  
  
  1 J. Magn. Reson. Imaging 2017;45:813-820.
authors: Department of Electrical and Computer Engineering, 205 Dreese Laboratories, The Ohio State University, Columbus, Ohio, USA.|Department of Radiology, Room 460, The Ohio State University, Columbus, Ohio, USA.|Department of Biomedical Engineering, 265 Kirkbride Hall, Walnut Street, Widener University, Chester, PA.
authors: Ria
authors: R
authors: Mazumder
authors: Department of Radiology, Room 460, The Ohio State University, Columbus, Ohio, USA.|Department of Mechanical Engineering, The Ohio State University, Columbus, Ohio, USA.
authors: Samuel
authors: S
authors: Schroeder
authors: Center for Biostatistics, Department of Biomedical Informatics, Room 320D, Lincoln Tower, Columbus, Ohio, USA.
authors: Xiaokui
authors: X
authors: Mo
authors: Department of Electrical and Computer Engineering, 205 Dreese Laboratories, The Ohio State University, Columbus, Ohio, USA.
authors: Bradley D
authors: BD
authors: Clymer
authors: Department of Radiology, Room 460, The Ohio State University, Columbus, Ohio, USA.|Department of Internal Medicine-Division of Cardiovascular Medicine, 244 Davis Heart & Lung Research Institute, The Ohio State University, Columbus, Ohio, USA.
authors: Richard D
authors: RD
authors: White
authors: Department of Radiology, Room 460, The Ohio State University, Columbus, Ohio, USA.|Department of Internal Medicine-Division of Cardiovascular Medicine, 244 Davis Heart & Lung Research Institute, The Ohio State University, Columbus, Ohio, USA.
authors: Arunark
authors: A
authors: Kolipaka
mesh_terms: D000818:Animals; D057791:Cardiac Imaging Techniques / Q000379:methods; D003198:Computer Simulation; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006973:Hypertension / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008955:Models, Cardiovascular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D013552:Swine
keywords: cardiac MRE; hypertension; left ventricular hypertrophy; magnetic resonance elastography; myocardial stiffness