title: Perfusion weighted color maps for enhanced visualization of myocardial infarction by MSCT: preliminary experience.
abstract: OBJECTIVE
  The reliable detection of myocardial perfusion defects and myocardial infarction (MI) is of great interest in the comprehensive workup of coronary artery disease. The aim of this study was to optimize the ability of contrast-enhanced cardiac multislice spiral computed tomography (MSCT) for detecting hypoperfused myocardium as surrogate marker of MI using a newly developed post-processing technique.
  
  
  METHODS
  First a model-based software tool for semi-automated detection of the long axis of the left ventricle and assignment of left-ventricular segments was developed using a region growing algorithm and a point distribution model. To visualize changes of the myocardial contrast enhancement pattern color coding was performed after spreading of the attenuation values. 15 patients (12 men, mean age 57 +/- 15 years) with a history of MI underwent cardiac MSCT (16 x 0.75 mm, 120 kV, 550 mA s(eff.), 100 ml Iopromide) and contrast enhanced delayed enhanced magnetic resonance imaging (DE-MRI) after administration of 0.2 mmol Gd-DTPA/kg/bodyweight as reference standard. Presence of infarction was assessed from MSCT, post-processed MSCT images and DE-MRI using a 17-segment model of the left ventricle.
  
  
  RESULTS
  On DE-MRI MI was present in 78/255 myocardial segments. From conventional MSCT images MI was detected in 63/255 segments (5 false positive; sensitivity 74.4%; specificity: 97.1%), while on post-processed images MI was assigned to 74/255 segments (6 false positive; sensitivity 87.2%; specificity: 96.6%). Agreement between DE-MRI and conventional MSCT images for detecting MI was kappa = 0.756. Using post-processed images agreement improved to kappa = 0.850.
  
  
  CONCLUSIONS
  MSCT detection of hypoperfused myocardium as surrogate for MI can be improved using dedicated post processing algorithms.
authors.affiliation: Department of Diagnostic Radiology, University Hospital, RWTH-Aachen University, Aachen, Germany. mahnken@rad.rwth-aachen.de
authors.forename: Andreas Horst
authors.initials: AH
authors.lastname: Mahnken
authors.forename: Stefan
authors.initials: S
authors.lastname: Lautenschläger
authors.forename: Dominik
authors.initials: D
authors.lastname: Fritz
authors.forename: Ralf
authors.initials: R
authors.lastname: Koos
authors.forename: Michael
authors.initials: M
authors.lastname: Scheuering
mesh_terms: D000465:Algorithms; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D011857:Radiographic Image Interpretation, Computer-Assisted; D012680:Sensitivity and Specificity; D012984:Software; D036542:Tomography, Spiral Computed
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA