title: Late gadolinium-enhanced magnetic resonance imaging in acute and chronic myocardial infarction. Improved prediction of regional myocardial contraction in the chronic state by measuring thickness of nonenhanced myocardium.
abstract: OBJECTIVE
  We sought to determine serial changes of enhanced and nonenhanced tissue on late gadolinium-enhanced cardiac magnetic resonance (CMR) imaging in patients with a myocardial infarction (MI) and to assess whether thickness of nonenhanced myocardium can improve the detection of preserved contractile function in the chronic state.
  
  
  BACKGROUND
  Previous studies demonstrated that enhancement on late gadolinium-enhanced CMR images indicates myocardial necrosis, and nonenhancement shows the presence of viable myocardium.
  
  
  METHODS
  The CMR studies were performed within one week (scan 1) and more than five months (scan 2) after the onset of MI in 18 patients. The area and mean thickness of enhanced tissue and nonenhanced myocardium were measured by using a 30-segment model. Systolic wall thickening on cine CMR at scan 2 was assessed for evaluating regional contractile function.
  
  
  RESULTS
  The amount of enhanced tissue significantly decreased from scan 1 to 2 (22.1 +/- 14.0 ml vs. 15.0 +/- 9.3 ml, p < 0.001). The averaged thickness of nonenhanced myocardium in the infarct segments significantly increased from scan 1 to 2 (5.2 +/- 3.0 mm vs. 6.6 +/- 3.2 mm, p < 0.001). Receiver operating characteristic analysis demonstrated that the measurement of thickness of nonenhanced myocardium, compared with measurement of percent transmural enhancement, had better diagnostic accuracy for predicting improved systolic wall thickening form scan 1 to 2 in dysfunctional segments (Az 0.650 vs. 0.594, p < 0.05).
  
  
  CONCLUSIONS
  The amounts of enhanced tissue and nonenhanced myocardium significantly altered from the acute to chronic state in MI patients. The diagnostic performance of CMR imaging for detection of preserved contractile function can be significantly improved by measuring thickness of nonenhanced myocardium in MI patients.
authors.affiliation: Department of Radiology, Matsusaka Central Hospital, Mie, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Ichikawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Sakuma
authors.forename: Naohisa
authors.initials: N
authors.lastname: Suzawa
authors.forename: Kakuya
authors.initials: K
authors.lastname: Kitagawa
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Makino
authors.forename: Tadanori
authors.initials: T
authors.lastname: Hirano
authors.forename: Kan
authors.initials: K
authors.lastname: Takeda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003287:Contrast Media / Q000008:administration & dosage*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology / Q000648:ultrastructure; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology*; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000473:pathology* / Q000648:ultrastructure*; D011237:Predictive Value of Tests; D011856:Radiographic Image Enhancement; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA