title: Three-dimensional phase-sensitive inversion-recovery Turbo FLASH sequence for the assessment of left ventricular myocardial scar in swine.
abstract: OBJECTIVE
  We sought to evaluate the feasibility and accuracy of free-breathing three-dimensional (3D) phase-sensitive inversion-recovery (PSIR) Turbo FLASH sequence for noninvasive assessment of left ventricular myocardial scar in swine models.
  
  
  METHODS
  Nine Chinese minipigs with experimentally induced acute myocardial infarction were studied. At 1 week and the study endpoint 4 weeks after myocardial infarction surgery, the 3D and 2D contrasted cardiac magnetic resonance (CMR) imaging were performed randomly by using a 1.5 T clinical MR imaging system. Comparisons of myocardial scar volume (in cubic centimeters), scar transmurality (on a 5 points scale) and image quality (on a 4 points Likert scale) were performed by using the Pearson correlation and Bland-Altman analysis (for myocardial scar volume) or κ statistics (for transmurality) or Wilcoxon signed rank test (for image quality).
  
  
  RESULTS
  In 6 of the 9 pigs, all procedures were successfully completed. In these pigs, a total of 48 segments with myocardial scars were detected by both 3D and 2D sequences, and there was good agreement for classification of scar transmurality (κ=0.930). The scar volume determined by triphenyltetrazolium chloride (TTC) staining (3.52 ± 1.40 cm(3)) showed a good correlation with both 3D (3.54 ± 1.36 cm(3), r=0.957, P=0.003) and 2D sequence (3.53 ± 1.26 cm(3), r=0.942, P=0.005) at 4 weeks. And there were good correlation between scar volumes obtained from 3D and 2D techniques (r=0.859, P<0.001) at both time points. Both 3D and 2D images detected a small reduction of scar volume from week 1 to week 4 by a factor of 1.179 and 1.176, respectively. Although slightly more artifacts were observed on 2D PSIR images, the overall image quality was not significantly different between the two sequences (3.17 ± 0.83 for 2D vs. 3.25 ± 0.75 for 3D, P =0.655).
  
  
  CONCLUSIONS
  The free-breathing 3D PSIR Turbo FLASH sequence enables accurate assessment of left ventricular myocardial scar.
authors.affiliation: Department of Radiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Xiuyu
authors.initials: X
authors.lastname: Chen
authors.forename: Minjie
authors.initials: M
authors.lastname: Lu
authors.forename: Gang
authors.initials: G
authors.lastname: Yin
authors.forename: Tao
authors.initials: T
authors.lastname: Zhao
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Shao
authors.forename: Ranxu
authors.initials: R
authors.lastname: Zhao
authors.forename: Yue
authors.initials: Y
authors.lastname: Tang
authors.forename: Jing
authors.initials: J
authors.lastname: An
authors.forename: Shiliang
authors.initials: S
authors.lastname: Jiang
authors.forename: Shihua
authors.initials: S
authors.lastname: Zhao
mesh_terms: D000818:Animals; D002921:Cicatrix / Q000473:pathology*; D006352:Heart Ventricles / Q000473:pathology*; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging; D009206:Myocardium / Q000473:pathology*; D018709:Statistics, Nonparametric; D013552:Swine; D013556:Swine, Miniature; D013778:Tetrazolium Salts
chemical_list: D013778:Tetrazolium Salts; C009591:triphenyltetrazolium