title: T2 mapping at 7T MRI can quantitatively assess intramyocardial hemorrhage in rats with acute reperfused myocardial infarction in vivo.
abstract: To investigate T2 mapping at 7T magnetic resonance imaging (MRI) for the detection and quantification of reperfused intramyocardial hemorrhage (IMH) in a rat model.
  
  
  
  Myocardial infarction (MI) was induced in 25 female rats. Rats were scanned at a 7T MRI 48 hours after reperfusion, using T2 mapping and late gadolinium enhancement imaging. Gross sections of the left ventricular myocardium and corresponding hematoxylin and eosin staining were assessed for IMH. T2 mapping images were matched with the gross sections. The IMH volume, expressed as a percentage of the left ventricular myocardial volume, of each heart determined by T2 mapping was compared with that calculated by pathological gross examination.
  
  
  
  Six rats died. In all, 97 gross sections of the left ventricular myocardium from the 19 rats were matched with T2 mapping images. IMH occurred pathologically in 68 gross sections, which was detected as hypointense cores by T2 mapping in 63 images (93% sensitivity). Three T2 mapping images with hypointense cores showed no hemorrhage on pathological sections (90% specificity). The positive and negative predictive values of hemorrhage on T2 mapping were 95% and 84%, respectively. In terms of the IMH volume, there was no significant difference between T2 mapping and pathological gross measurements (4.8 ± 2.4% vs. 5.3 ± 3.2%; P = 0.11).
  
  
  
  T2 mapping at 7T MRI can reliably detect and quantify IMH in rats in vivo. This may be useful as a noninvasive quantitative approach to investigating the mechanisms and evolution of MI and reperfusion injury. J. Magn. Reson. Imaging 2016;44:194-203.
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.|Department of Radiology, First Affiliated Hospital of Kunming Medical University, Kunming, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.|Department of Radiology, First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Xia
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Ruzhi
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Ziqian
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Yushu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Chunhua
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Fabao
authors.initials: F
authors.lastname: Gao
mesh_terms: D000465:Algorithms; D000818:Animals; D005260:Female; D006470:Hemorrhage / Q000000981:diagnostic imaging* / Q000209:etiology*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D015428:Myocardial Reperfusion Injury / Q000150:complications* / Q000000981:diagnostic imaging*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: T2 mapping; cardiac magnetic resonance; ischemia/reperfusion injury; myocardial edema; myocardial hemorrhage; myocardial infarction