title: Different algorithms for quantitative analysis of myocardial infarction with DE MRI: comparison with autopsy specimen measurements.
abstract: OBJECTIVE
  To compare two semiautomated methods for measurement of infarcted myocardium area on delayed contrast enhanced magnetic resonance imaging, with histopathology findings as standard of reference.
  
  
  METHODS
  Percentage area of myocardial infarction was measured in 10 Yorkshire landrace pigs manually and using two semiautomated methods. The first (standard deviation method) used two operator-selected regions of interest (ROIs) and nine different cutoff values (one to nine times the standard deviation of signal intensity in normal myocardium) to identify infarction. The second (threshold method) used threshold values based on percentages of maximum signal intensity to identify infarction. Results were compared with histopathology findings.
  
  
  RESULTS
  Difference between percentage area of infarction obtained with standard deviation method and autopsy specimens was in the range: -13.5% to +13.2%. With threshold method (thresholds from 30% to 90% of signal intensity), difference was -15% to +23%. Manual contouring underestimated infarcted area by 2% comparing to autopsy results. The best agreement between histopathology and semi-automated software was achieved for 4 standard deviations with standard deviation method: difference -0.45%, and for a percentage threshold of 70% (difference +0.67%) with threshold method. However, with standard deviation method, there was statistically significant difference between ROIs based on their location in viable myocardium: mean difference 1.7 ± 4%, P < .0001.
  
  
  CONCLUSIONS
  Semiautomated measurement of myocardial infarcted area on delayed enhanced magnetic resonance images performs well compared to autopsy. The threshold method, based on percentages of maximum signal intensity is preferable over standard deviation method, which is more susceptible to variability from location of ROIs within viable myocardium.
authors: Department of Radiology, Erasmus MC, Universitair Medisch Centrum, Thoraxcenter, Ba 585, 's-Gravendijkwal 230, 3015 CE Rotterdam, the Netherlands.
authors: Katarzyna
authors: K
authors: Gruszczynska
authors: Sharon
authors: S
authors: Kirschbaum
authors: Timo
authors: T
authors: Baks
authors: Amber
authors: A
authors: Moelker
authors: Dirk J
authors: DJ
authors: Duncker
authors: Alexia
authors: A
authors: Rossi
authors: Jan
authors: J
authors: Baron
authors: Pim J
authors: PJ
authors: de Feyter
authors: Gabriel P
authors: GP
authors: Krestin
authors: Robert-Jan M
authors: RJ
authors: van Geuns
mesh_terms: D000465:Algorithms; D000818:Animals; D001344:Autopsy; D003287:Contrast Media; D003936:Diagnosis, Computer-Assisted; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009203:Myocardial Infarction / Q000473:pathology*; D013552:Swine
chemical_list: D003287:Contrast Media