title: Evaluate the early changes of myocardial fibers in rhesus monkey during sub-acute stage of myocardial infarction using diffusion tensor magnetic resonance imaging.
abstract: OBJECTIVE
  The deterioration of cardiac mechanical function starts from the micro-alterations in the myocardial fibers after myocardial infarction (MI) due to the heart beats derived from the systole and diastole of the myocardial fibers. So, we want to evaluate quantitatively the early changes of myocardial fibers in rhesus monkey during sub-acute MI stage.
  
  
  METHODS
  Three fixed hearts with infarction after left anterior descending coronary artery ligation for 7days and eight age-matched intact controls were scanned by ex-vivo diffusion tensor magnetic resonance imaging (DT-MRI) to measure apparent diffusion coefficient (ADC), fractional anisotropy (FA) and helix angle (HA).
  
  
  RESULTS
  In comparison with healthy controls, FA and transmural range of HA in MI regions showed a significant reduction whereas ADC showed a significant increment (p<0.01). The double-helix myocardial fibers shifted further to left-handed helix around the infarcted and adjacent myocardium but shifted further to right-handed helix in remote myocardium.
  
  
  CONCLUSIONS
  HA is sensitive to evaluate quantitatively the early changes of myocardial fibers in sub-acute MI rhesus monkeys. The myocardial fibers in normal monkeys are similar to those in normal humans, suggesting that early changes of myocardial fibers in sub-acute MI monkeys can contribute to more accurately understand those in patients suffering sub-acute MI.
authors.affiliation: CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China, No.11 ZhongGuanCun BeiYiTiao, Beijing, 100190, China. Electronic address: wyq112925@163.com.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Radiology, Beijing Jishuitan Hospital, 4th clinical medical college of Peking University, No.31 Xinjiekou East Road, Beijing, China, 100035.
authors.forename: Wei
authors.initials: W
authors.lastname: Cai
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, No.37 Guoxue Alley, Chengdu, Sichuan, China, 610041.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Radiology, The First Affiliated Hospital, Chongqing Medical University, No.1 Friendship Road, Chongqing, China, 400016.
authors.forename: Rui
authors.initials: R
authors.lastname: Xia
mesh_terms: D000818:Animals; D038524:Diffusion Magnetic Resonance Imaging; D056324:Diffusion Tensor Imaging; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D008253:Macaca mulatta; D008297:Male; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000473:pathology; D009206:Myocardium / Q000473:pathology*
keywords: Helix angle; Myocardial fiber; Myocardial infarction; Rhesus monkey