title: Assessment of left ventricular mechanical dyssynchrony in left bundle branch block canine model: Comparison between cine and tagged MRI.
abstract: To compare cine and tagged magnetic resonance imaging (MRI) for left ventricular dyssynchrony assessment in left bundle branch block (LBBB), using the time-to-peak contraction timing, and a novel approach based on cross-correlation.
  
  
  
  We evaluated a canine model dataset (n = 10) before (pre-LBBB) and after induction of isolated LBBB (post-LBBB). Multislice short-axis tagged and cine MRI images were acquired using a 1.5 T scanner. We computed contraction time maps by cross-correlation, based on the timing of radial wall motion and of circumferential strain. Finally, we estimated dyssynchrony as the standard deviation of the contraction time over the different regions of the myocardium.
  
  
  
  Induction of LBBB resulted in a significant increase in dyssynchrony (cine: 13.0 ± 3.9 msec for pre-LBBB, and 26.4 ± 5.0 msec for post-LBBB, P = 0.005; tagged: 17.1 ± 5.0 msec at for pre-LBBB, and 27.9 ± 9.8 msec for post-LBBB, P = 0.007). Dyssynchrony assessed by cine and tagged MRI were in agreement (r = 0.73, P = 0.0003); differences were in the order of time difference between successive frames of 20 msec (bias: -2.9 msec; limit of agreement: 10.1 msec). Contraction time maps were derived; agreement was found in the contraction patterns derived from cine and tagged MRI (mean difference in contraction time per segment: 3.6 ± 13.7 msec).
  
  
  
  This study shows that the proposed method is able to quantify dyssynchrony after induced LBBB in an animal model. Cine-assessed dyssynchrony agreed with tagged-derived dyssynchrony, in terms of magnitude and spatial direction. J. MAGN. RESON. IMAGING 2016;44:956-963.
authors.affiliation: Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands. s.saporito@tue.nl.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Saporito
authors.affiliation: Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.
authors.forename: Hans C
authors.initials: HC
authors.lastname: van Assen
authors.affiliation: Department of Cardiology, Catharina Hospital Eindhoven, Eindhoven, the Netherlands.
authors.forename: Patrick
authors.initials: P
authors.lastname: Houthuizen
authors.affiliation: Pie Medical Imaging BV, Maastricht, the Netherlands.
authors.forename: Jean-Paul M M
authors.initials: JP
authors.lastname: Aben
authors.affiliation: Department of Physiology, Maastricht University, Cardiovascular Research Institute Maastricht, Maastricht, the Netherlands.
authors.forename: Marc
authors.initials: M
authors.lastname: Strik
authors.affiliation: Department of Physiology, Maastricht University, Cardiovascular Research Institute Maastricht, Maastricht, the Netherlands.
authors.forename: Lars B
authors.initials: LB
authors.lastname: van Middendorp
authors.affiliation: Department of Physiology, Maastricht University, Cardiovascular Research Institute Maastricht, Maastricht, the Netherlands.
authors.forename: Frits W
authors.initials: FW
authors.lastname: Prinzen
authors.affiliation: Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.
authors.forename: Massimo
authors.initials: M
authors.lastname: Mischi
mesh_terms: D000818:Animals; D002037:Bundle-Branch Block / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D057791:Cardiac Imaging Techniques / Q000379:methods*; D004285:Dogs; D056966:Excitation Contraction Coupling; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D009200:Myocardial Contraction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*
keywords: dyssynchrony; left bundle branch block; left ventricle; magnetic resonance imaging