title: Impact of the Advisa MRI pacing system on the diagnostic quality of cardiac MR images and contraction patterns of cardiac muscle during scans: Advisa MRI randomized clinical multicenter study results.
abstract: BACKGROUND
  The Advisa MRI system is designed to safely undergo magnetic resonance imaging (MRI). Its influence on image quality is not well known.
  
  
  OBJECTIVE
  To evaluate cardiac magnetic resonance (CMR) image quality and to characterize myocardial contraction patterns by using the Advisa MRI system.
  
  
  METHODS
  In this international trial with 35 participating centers, an Advisa MRI system was implanted in 263 patients. Of those, 177 were randomized to the MRI group and 150 underwent MRI scans at the 9-12-week visit. Left ventricular (LV) and right ventricular (RV) cine long-axis steady-state free precession MR images were graded for quality. Signal loss along the implantable pulse generator and leads was measured. The tagging CMR data quality was assessed as the percentage of trackable tagging points on complementary spatial modulation of magnetization acquisitions (n=16) and segmental circumferential fiber shortening was quantified.
  
  
  RESULTS
  Of all cine long-axis steady-state free precession acquisitions, 95% of LV and 98% of RV acquisitions were of diagnostic quality, with 84% and 93%, respectively, being of good or excellent quality. Tagging points were trackable from systole into early diastole (360-648 ms after the R-wave) in all segments. During RV pacing, tagging demonstrated a dyssynchronous contraction pattern, which was not observed in nonpaced (n = 4) and right atrial-paced (n = 8) patients.
  
  
  CONCLUSIONS
  In the Advisa MRI study, high-quality CMR images for the assessment of cardiac anatomy and function were obtained in most patients with an implantable pacing system. In addition, this study demonstrated the feasibility of acquiring tagging data to study the LV function during pacing.
authors: University Hospital Lausanne, CHUV, Lausanne, Switzerland. jurg.schwitter@chuv.ch
authors: Juerg
authors: J
authors: Schwitter
authors: Emanuel
authors: E
authors: Kanal
authors: Matthias
authors: M
authors: Schmitt
authors: Frederic
authors: F
authors: Anselme
authors: Timothy
authors: T
authors: Albert
authors: David L
authors: DL
authors: Hayes
authors: David
authors: D
authors: Bello
authors: Attila
authors: A
authors: Tóth
authors: Yanping
authors: Y
authors: Chang
authors: Dirk
authors: D
authors: van Osch
authors: Torsten
authors: T
authors: Sommer
mesh_terms: D016477:Artifacts; D002304:Cardiac Pacing, Artificial; D003971:Diastole / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine / Q000295:instrumentation; D009200:Myocardial Contraction / Q000502:physiology*; D010138:Pacemaker, Artificial; D013599:Systole / Q000502:physiology; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right