title: Hemodynamic aspects of mitral regurgitation assessed by generalized phase-contrast MRI.
abstract: OBJECTIVE
  To investigate the utility of MRI measurement of left atrial (LA) flow patterns and turbulent kinetic energy (TKE) in patients with clinically significant mitral regurgitation.
  
  
  METHODS
  Three-dimensional cine phase-contrast MRI (PC-MRI) data were acquired in five patients with posterior mitral leaflet prolapse and two normal volunteers. LA flow patterns were assessed using particle trace visualization. Specifically, vortices were recognized by closed streamlines. LA flow distortion was assessed by estimation of TKE. In addition, the regurgitant volume was measured.
  
  
  RESULTS
  Four of the mitral regurgitation patients had eccentric regurgitant jets directed toward the septum; one patient had a central jet. The dominant systolic vortex was located in proximity to the regurgitant jet. The LA flow was highly disturbed with elevated values of TKE; peak LA TKE ranged from 13 to 37 mJ and occurred consistently at late systole. The average LA TKE per cardiac cycle was significantly related to the regurgitant volume (TKE = 0.573 + 0.179·RegVol, R(2) = 0.983).
  
  
  CONCLUSIONS
  MRI permits investigations of atrial flow patterns and TKE in significant mitral regurgitation. The degree of LA flow distortion, as measured by the average LA TKE over one cardiac cycle, appears to reflect the severity of regurgitation.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. petter.dyverfeldt@liu.se
authors.forename: Petter
authors.initials: P
authors.lastname: Dyverfeldt
authors.forename: John-Peder Escobar
authors.initials: JP
authors.lastname: Kvitting
authors.forename: Carl Johan
authors.initials: CJ
authors.lastname: Carlhäll
authors.forename: Gabriella
authors.initials: G
authors.lastname: Boano
authors.forename: Andreas
authors.initials: A
authors.lastname: Sigfridsson
authors.forename: Ulf
authors.initials: U
authors.lastname: Hermansson
authors.forename: Ann F
authors.initials: AF
authors.lastname: Bolger
authors.forename: Jan
authors.initials: J
authors.lastname: Engvall
authors.forename: Tino
authors.initials: T
authors.lastname: Ebbers
mesh_terms: D000328:Adult; D000368:Aged; D016279:Atrial Function, Left; D003952:Diagnostic Imaging / Q000379:methods; D004452:Echocardiography / Q000379:methods; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D007700:Kinetics; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000473:pathology*; D008944:Mitral Valve Insufficiency / Q000503:physiopathology*; D015233:Models, Statistical