title: Irreversibly damaged myocardium at MR imaging with a necrotic tissue-specific contrast agent in a cat model.
abstract: OBJECTIVE
  To investigate the capability of a necrosis-avid magnetic resonance (MR) contrast agent, bis-gadolinium mesoporphyrins, for assessment of irreversibly damaged myocardium and to evaluate the time course of signal enhancement in the reperfused myocardium.
  
  
  METHODS
  Nine cats were subjected to 90 minutes of occlusion of the left anterior descending coronary artery followed by 90 minutes of reperfusion. Contrast material-enhanced T1-weighted spin-echo images were obtained for 12 hours in five cats and 6 hours in four cats. Pathologic examinations of the resected specimens were performed with 2'3'5-triphenyl tetrazolium chloride (TTC) histochemical staining and electron microscopy. The size of enhanced area on MR images was compared with that of irreversibly damaged myocardium with TTC staining. The time course of signal enhancement was evaluated.
  
  
  RESULTS
  The size of enhanced area on MR images was well correlated with that of irreversibly damaged myocardium with TTC staining. Maximum enhancement occurred 1-3 hours after administration of the contrast material, with mean enhancement of 171% that of normal myocardium. Electron microscopic examinations showed severe myocardial damage in the irreversibly damaged myocardium but only mild edematous changes in the reversibly damaged myocardium.
  
  
  CONCLUSIONS
  MR images enhanced with bis-gadolinium mesoporphyrins provide accurate sizing of irreversibly damaged myocardium with a strong and persistent signal enhancement in the reperfused myocardium.
authors.affiliation: Department of Diagnostic Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: S I
authors.initials: SI
authors.lastname: Choi
authors.forename: S H
authors.initials: SH
authors.lastname: Choi
authors.forename: S T
authors.initials: ST
authors.lastname: Kim
authors.forename: K H
authors.initials: KH
authors.lastname: Lim
authors.forename: C H
authors.initials: CH
authors.lastname: Lim
authors.forename: G Y
authors.initials: GY
authors.lastname: Gong
authors.forename: H Y
authors.initials: HY
authors.lastname: Kim
authors.forename: H J
authors.initials: HJ
authors.lastname: Weinmann
authors.forename: T H
authors.initials: TH
authors.lastname: Lim
mesh_terms: D000818:Animals; D002415:Cats; D003287:Contrast Media; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D005682:Gadolinium; D006651:Histocytochemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008665:Metalloporphyrins; D008854:Microscopy, Electron; D015428:Myocardial Reperfusion Injury / Q000175:diagnosis* / Q000473:pathology; D009206:Myocardium / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D009336:Necrosis; D013997:Time Factors
chemical_list: D003287:Contrast Media; D008665:Metalloporphyrins; C112663:gadolinium mesoporphyrin; D005682:Gadolinium