title: Delayed enhancement and T2-weighted cardiovascular magnetic resonance imaging differentiate acute from chronic myocardial infarction.
abstract: BACKGROUND
  Delayed enhancement (DE) cardiovascular magnetic resonance (CMR) detects acute and chronic myocardial infarction (MI) by visualizing contrast media accumulation in infarcted segments. T2-weighted CMR depicts infarct-related myocardial edema as a marker of acute but not chronic myocardial injury. We investigated the clinical utility of an approach combining both techniques to differentiate acute from chronic MI.
  
  
  RESULTS
  Seventy-three MI patients were studied in 2 groups. Group A consisted of 15 acute MI patients who were studied twice, on day 1 and 3 months after MI. In group B, 58 patients with acute or chronic MI underwent 1 CMR scan. T2-weighted and DE images of matched slices were acquired on a 1.5-T system. In group A, quantitative segmental and region of interest-based analyses were performed to observe signal changes between the acute and chronic phases. In group B, T2-weighted and DE images were examined visually by 2 blinded observers for the presence or absence of hyperintense areas in corresponding segments. For infarct localization, coronary angiography and/or ECG changes served as the reference standard. In group A, the contrast-to-noise ratio on T2-weighted images dropped in the infarcted segments from 2.7+/-1.1 on day 1 to 0.1+/-1.2 after 3 months (P<0.0001). There was no significant change in contrast-to-noise ratio in DE images (1.9+/-1.5 versus 1.3+/-1.0; P=NS). The qualitative assessment of T2-weighted and DE images in group B yielded a specificity of 96% to differentiate acute from chronic lesions.
  
  
  CONCLUSIONS
  An imaging approach combining DE and T2-weighted CMR accurately differentiates acute from chronic MI.
authors.affiliation: Franz-Volhard-Klinik, Helios-Klinikum Berlin, Kardiologie, Charité Campus Berlin-Buch, Humboldt-Universität zu Berlin, Berlin, Germany.
authors.forename: Hassan
authors.initials: H
authors.lastname: Abdel-Aty
authors.forename: Anja
authors.initials: A
authors.lastname: Zagrosek
authors.forename: Jeanette
authors.initials: J
authors.lastname: Schulz-Menger
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Taylor
authors.forename: Daniel
authors.initials: D
authors.lastname: Messroghli
authors.forename: Andreas
authors.initials: A
authors.lastname: Kumar
authors.forename: Michael
authors.initials: M
authors.lastname: Gross
authors.forename: Rainer
authors.initials: R
authors.lastname: Dietz
authors.forename: Matthias G
authors.initials: MG
authors.lastname: Friedrich
mesh_terms: D000208:Acute Disease; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D013997:Time Factors