title: Myocardial infarct size quantification in mice by SPECT using a novel algorithm independent of a normal perfusion database.
abstract: BACKGROUND
  There is a growing interest in developing non-invasive imaging techniques permitting infarct size (IS) measurements in mice. The aim of this study was to validate the high-resolution rodent Linoview single photon emission computed tomography (SPECT) system for non-invasive measurements of IS in mice by using a novel algorithm independent of a normal database, in comparison with histology.
  
  
  METHODS
  Eleven mice underwent a left coronary artery ligature. Seven days later, animals were imaged on the SPECT 2h30 after injection of 173 ± 27 MBq of Tc-99m-sestamibi. Mice were subsequently killed, and their hearts were excised for IS determination with triphenyltetrazolium chloride (TTC) staining. SPECT images were reconstructed using the expectation maximization maximum likelihood algorithm, and the IS was calculated using a novel algorithm applied on the 20-segment polar map provided by the commercially available QPS software (Cedars-Sinai Medical Center, CA, USA). This original method is attractive by the fact that it does not require the implementation of a normal perfusion database.
  
  
  RESULTS
  Reconstructed images allowed a clear delineation of the left ventricles borders in all mice. No significant difference was found between mean IS determined by SPECT and by TTC staining [37.9 ± 17.5% vs 35.6 ± 17.2%, respectively (P = 0.10)]. Linear regression analysis showed an excellent correlation between IS measured on the SPECT images and IS obtained with TTC staining (y = 0.95x + 0.03 (r = 0.97; P < 0.0001)), without bias, as demonstrated by the Bland-Altman plot.
  
  
  CONCLUSIONS
  Our results demonstrate the accuracy of the method for the measurement of myocardial IS in mice with the Linoview SPECT system.
authors.affiliation: Institut de Recherche Expérimentale et Clinique, Pôle d'Imagerie Moléculaire, Radiothérapie et Oncologie and Pôle de Recherche Cardiovasculaire, Université Catholique de Louvain, Brussels, 1200, Belgium. veronique.roelants@uclouvain.be.
authors.forename: Véronique
authors.initials: V
authors.lastname: Roelants
authors.forename: Marie
authors.initials: M
authors.lastname: Delgaudine
authors.forename: Stephan
authors.initials: S
authors.lastname: Walrand
authors.forename: Renaud
authors.initials: R
authors.lastname: Lhommel
authors.forename: Yves
authors.initials: Y
authors.lastname: Beguin
authors.forename: François
authors.initials: F
authors.lastname: Jamar
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vanoverschelde