title: MR imaging of reperfused myocardial infarction: comparison of necrosis-specific and intravascular contrast agents in a cat model.
abstract: OBJECTIVE
  To compare T2-weighted and Gadomer-17- and bis-gadolinium mesoporphyrins-enhanced magnetic resonance (MR) images for distinguishing reversibly from irreversibly damaged myocardium in a cat model of reperfused myocardial infarction.
  
  
  METHODS
  Twelve cats underwent 90 minutes of occlusion and 90 minutes of reperfusion of the left anterior descending coronary artery. After baseline T1- and T2-weighted MR images were obtained, Gadomer-17-enhanced and bis-gadolinium mesoporphyrins-enhanced T1-weighted images were sequentially obtained for 6 hours and 2 hours, respectively. After MR imaging, all cats were sacrificed for 2,3,5-triphenyltetrazolium chloride (TTC) histochemical tissue staining. Areas of abnormal signal intensity on T2-weighted and Gadomer-17-enhanced and bis-gadolinium mesoporphyrins-enhanced T1-weighted MR images were compared with the areas of infarction seen at TTC histochemical staining by using repeated-measures two-way analysis of variance, linear regression analysis, and Bland-Altman analysis.
  
  
  RESULTS
  Mean areas of abnormally high signal intensity on T2-weighted and Gadomer-17-enhanced T1-weighted MR images (43.9% of the left ventricular surface area +/- 11.9 [SD] and 37.7% +/- 10.1, respectively) were significantly larger than the mean area of myocardial infarction at TTC staining (25.7% +/- 12.5) (P <.001). However, there was excellent correlation between the size of an enhancing area on bis-gadolinium mesoporphyrins-enhanced T1-weighted MR images and that of myocardial infarction at TTC staining (r = 0.916, P <.001).
  
  
  CONCLUSIONS
  bis-Gadolinium mesoporphyrins-enhanced T1-weighted MR images accurately reflect the area of infarction, whereas the size of infarction is overestimated on T2-weighted and Gadomer-17-enhanced T1-weighted MR images, which seem to depict the periinfarct area as well as the infarct area.
authors.affiliation: Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap-Dong, Songpa-Ku, Seoul 138-736, Korea.
authors.forename: Seung Soo
authors.initials: SS
authors.lastname: Lee
authors.forename: Hyun Woo
authors.initials: HW
authors.lastname: Goo
authors.forename: Sung Bin
authors.initials: SB
authors.lastname: Park
authors.forename: Chung Hwan
authors.initials: CH
authors.lastname: Lim
authors.forename: Gyungyub
authors.initials: G
authors.lastname: Gong
authors.forename: Joon Beom
authors.initials: JB
authors.lastname: Seo
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Lim
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002415:Cats; D003287:Contrast Media / Q000008:administration & dosage; D004195:Disease Models, Animal; D005682:Gadolinium / Q000008:administration & dosage; D007275:Injections, Intravenous; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008665:Metalloporphyrins / Q000008:administration & dosage; D008854:Microscopy, Electron; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology; D009336:Necrosis
chemical_list: D003287:Contrast Media; D008665:Metalloporphyrins; C112663:gadolinium mesoporphyrin; C402765:gadomer 17; D005682:Gadolinium