title: Determination of infarct size in ex vivo swine hearts by multidetector computed tomography using gadolinium as contrast medium.
abstract: OBJECTIVE
  To demonstrate the feasibility of using multidetector computed tomography with gadolinium contrast (Gd-MDCT) for the quantification of myocardial infarct (MI).
  
  
  METHODS
  MI was induced in male swine (n = 6). One week later, the animals received 0.2-mmol/kg gadopentetate dimeglumine and were sacrificed. On the excised hearts, Gd-MDCT with several tube voltages (80, 120, and 140 kV), late gadolinium enhancement MRI (LGE-MRI), and triphenyl-tetrazolium-chloride staining were then conducted. We used a 2-SD threshold for the CT images and several threshold limits (2, 3, 4, 5, 6 SD, and full width at half-maximum [FWHM]) for the LGE-MRI images to delineate the infarct area. Total infarct volume and infarct fraction of each heart were calculated.
  
  
  RESULTS
  MI size measured by MDCT at 140 kV showed good correlation with the reference triphenyl-tetrazolium-chloride value. Applying an 80-kV tube voltage, however, significantly underestimated MI size. In our study, the LGE-MRI method, using the 6-SD threshold, provided the most accurate determination of MI size. LGE-MRI, using the 2- and 3-SD threshold limits, significantly overestimated infarct size.
  
  
  CONCLUSIONS
  The Gd-MDCT technique has been found suitable for the evaluation of MI in an ex vivo experimental setting. Gd-MDCT has the ability to detect MI even at low kV settings, but accuracy is limited by a high image noise because of reduced photon flux.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
authors.forename: Akos
authors.initials: A
authors.lastname: Varga-Szemes
authors.forename: Balazs
authors.initials: B
authors.lastname: Ruzsics
authors.forename: Robert
authors.initials: R
authors.lastname: Kirschner
authors.forename: Satinder P
authors.initials: SP
authors.lastname: Singh
authors.forename: Pal
authors.initials: P
authors.lastname: Kiss
authors.forename: Brigitta C
authors.initials: BC
authors.lastname: Brott
authors.forename: Tamas
authors.initials: T
authors.lastname: Simor
authors.forename: Ada
authors.initials: A
authors.lastname: Elgavish
authors.forename: Gabriel A
authors.initials: GA
authors.lastname: Elgavish
mesh_terms: D000465:Algorithms; D000818:Animals; D003287:Contrast Media; D005240:Feasibility Studies; D019786:Gadolinium DTPA; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D066298:In Vitro Techniques; D008297:Male; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA