title: Hepatic and splenic stiffness augmentation assessed with MR elastography in an in vivo porcine portal hypertension model.
abstract: OBJECTIVE
  To investigate the influence of portal pressure on the shear stiffness of the liver and spleen in a well-controlled in vivo porcine model with magnetic resonance elastography (MRE). A significant correlation between portal pressure and tissue stiffness could be used to noninvasively assess increased portal venous pressure (portal hypertension), which is a frequent clinical condition caused by cirrhosis of the liver and is responsible for the development of many lethal complications.
  
  
  METHODS
  During multiple intraarterial infusions of Dextran-40 in three adult domestic pigs in vivo, 3D abdominal MRE was performed with left ventricle and portal catheters measuring blood pressure simultaneously. Least-squares linear regressions were used to analyze the relationship between tissue stiffness and portal pressure.
  
  
  RESULTS
  Liver and spleen stiffness have a dynamic component that increases significantly following an increase in portal or left ventricular pressure. Correlation coefficients with the linear regressions between stiffness and pressure exceeded 0.8 in most cases.
  
  
  CONCLUSIONS
  The observed stiffness-pressure relationship of the liver and spleen could provide a promising noninvasive method for assessing portal pressure. Using MRE to study the tissue mechanics associated with portal pressure may provide new insights into the natural history and pathophysiology of hepatic diseases and may have significant diagnostic value in the future.
authors: Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Meng
authors: M
authors: Yin
authors: Arunark
authors: A
authors: Kolipaka
authors: David A
authors: DA
authors: Woodrum
authors: Kevin J
authors: KJ
authors: Glaser
authors: Anthony J
authors: AJ
authors: Romano
authors: Armando
authors: A
authors: Manduca
authors: Jayant A
authors: JA
authors: Talwalkar
authors: Philip A
authors: PA
authors: Araoz
authors: Kiaran P
authors: KP
authors: McGee
authors: Nandan S
authors: NS
authors: Anavekar
authors: Richard L
authors: RL
authors: Ehman
mesh_terms: D000818:Animals; D001794:Blood Pressure; D002404:Catheterization; D003911:Dextrans; D004195:Disease Models, Animal; D054459:Elasticity Imaging Techniques; D006352:Heart Ventricles / Q000473:pathology; D006975:Hypertension, Portal / Q000473:pathology*; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D016018:Least-Squares Analysis; D016014:Linear Models; D008099:Liver / Q000473:pathology*; D017082:Portal Pressure; D015203:Reproducibility of Results; D033081:Shear Strength; D013154:Spleen / Q000473:pathology*; D013552:Swine
chemical_list: D003911:Dextrans
keywords: MR elastography; liver; portal pressure; shear stiffness; spleen