title: Diffuse myocardial fibrosis following tetralogy of Fallot repair: a T1 mapping cardiac magnetic resonance study.
abstract: BACKGROUND
  Adverse ventricular remodeling after tetralogy of Fallot (TOF) repair is associated with diffuse myocardial fibrosis.
  
  
  OBJECTIVE
  The goal of this study was to measure post-contrast myocardial T1 in pediatric patients after TOF repair as surrogates of myocardial fibrosis.
  
  
  METHODS
  Children after TOF repair who underwent cardiac magnetic resonance imaging with T1 mapping using the modified look-locker inversion recovery (MOLLI) sequence were included. In addition to routine volumetric and flow data, we measured post-contrast T1 values of the basal interventricular septum, the left ventricular (LV) lateral wall, and the inferior and anterior walls of the right ventricle (RV). Results were compared to data from age-matched healthy controls.
  
  
  RESULTS
  The scans of 18 children who had undergone TOF repair and 12 healthy children were included. Post-contrast T1 values of the left ventricular lateral wall (443 ± 54 vs. 510 ± 77 ms, P = 0.0168) and of the right ventricular anterior wall (333 ± 62 vs. 392 ± 72 ms, P = 0.0423) were significantly shorter in children with TOF repair than in controls, suggesting a higher degree of fibrosis. In children with TOF repair, but not in controls, post-contrast T1 values were shorter in the right ventricle than the left ventricle and shorter in the anterior wall of the right ventricle than in the inferior segments. In the TOF group, post-contrast T1 values of the RV anterior wall correlated with the RV end-systolic volume indexed to body surface area (r = 0.54; r(2) = 0.30; P = 0.0238).
  
  
  CONCLUSIONS
  In children who underwent tetralogy of Fallot repair the myocardium of both ventricles appears to bear an abnormally high fibrosis burden.
authors.affiliation: Labatt Family Heart Centre in the Department of Paediatrics and Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, 555 University Ave., Toronto, Canada, M5G 1X8.
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Kozak
authors.forename: Andrew
authors.initials: A
authors.lastname: Redington
authors.forename: Shi-Joon
authors.initials: SJ
authors.lastname: Yoo
authors.forename: Mike
authors.initials: M
authors.lastname: Seed
authors.forename: Andreas
authors.initials: A
authors.lastname: Greiser
authors.forename: Lars
authors.initials: L
authors.lastname: Grosse-Wortmann
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D003287:Contrast Media; D005260:Female; D005355:Fibrosis / Q000175:diagnosis; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009206:Myocardium / Q000473:pathology*; D011183:Postoperative Complications / Q000175:diagnosis*; D013771:Tetralogy of Fallot / Q000601:surgery*; D020257:Ventricular Remodeling
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA