title: Diagnostic usefulness of the oedema-infarct ratio to differentiate acute from chronic myocardial damage using magnetic resonance imaging.
abstract: OBJECTIVE
  To differentiate acute from chronic damage to the myocardium in patients with myocardial infarction (MI) using DE and T2w MR.
  
  
  METHODS
  Short-axis T2w and DE MR images were acquired twice after the onset of MI in 36 patients who successfully underwent emergency coronary revascularisation. The areas of infarct and oedema were measured. The oedema-infarct ratio (O/I) of the left ventricular area was calculated by dividing the oedema by the infarct area.
  
  
  RESULTS
  The oedema size on T2w MR was significantly larger than the infarct size on DE MR in the acute phase. Both the oedema size on T2w MR and the infarct size on DE MR in the acute phase were significantly larger than those in the chronic phase. The O/I was significantly greater in the acute phase compared with that in the chronic phase (P < 0.05). An analysis of relative cumulative frequency distributions revealed an O/I of 1.4 as a cut-off value for differentiating acute from chronic myocardial damage with the sensitivity, specificity, and accuracy of 85.1%, 82.7% and 83.9%, respectively.
  
  
  CONCLUSIONS
  The oedema-infarct ratio may be a useful index in differentiating acute from chronic myocardial damage in patients with MI.
  
  
  CONCLUSIONS
  MR can differentiate reversible from irreversible myocardial damage after myocardial infarction. MR is a useful modality to noninvasively differentiate the infarct stages. The O/I is an important index to decide therapeutic strategies.
authors.affiliation: Department of Cardiology, Gifu Social Insurance Hospital, 1221-5, Dota, Kani, Gifu, 509-0206, Japan. yamakiyo@d6.dion.ne.jp
authors.forename: Kiyoyasu
authors.initials: K
authors.lastname: Yamada
authors.forename: Satoshi
authors.initials: S
authors.lastname: Isobe
authors.forename: Susumu
authors.initials: S
authors.lastname: Suzuki
authors.forename: Kousuke
authors.initials: K
authors.lastname: Kinoshita
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yokouchi
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Iwata
authors.forename: Satoru
authors.initials: S
authors.lastname: Ohshima
authors.forename: Makoto
authors.initials: M
authors.lastname: Hirai
authors.forename: Ken
authors.initials: K
authors.lastname: Sawada
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Murohara
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003937:Diagnosis, Differential; D004487:Edema / Q000150:complications / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity