title: Reproducibility of small animal cine and scar cardiac magnetic resonance imaging using a clinical 3.0 tesla system.
abstract: BACKGROUND
  To evaluate the inter-study, inter-reader and intra-reader reproducibility of cardiac cine and scar imaging in rats using a clinical 3.0 Tesla magnetic resonance (MR) system.
  
  
  METHODS
  Thirty-three adult rats (Sprague-Dawley) were imaged 24 hours after surgical occlusion of the left anterior descending coronary artery using a 3.0 Tesla clinical MR scanner (Philips Healthcare, Best, The Netherlands) equipped with a dedicated 70 mm solenoid receive-only coil. Left-ventricular (LV) volumes, mass, ejection fraction and amount of myocardial scar tissue were measured. Intra-and inter-observer reproducibility was assessed in all animals. In addition, repeat MR exams were performed in 6 randomly chosen rats within 24 hours to assess inter-study reproducibility.
  
  
  RESULTS
  The MR imaging protocol was successfully completed in 32 (97%) animals. Bland-Altman analysis demonstrated high intra-reader reproducibility (mean bias%: LV end-diastolic volume (LVEDV), -1.7%; LV end-systolic volume (LVESV), -2.2%; LV ejection fraction (LVEF), 1.0%; LV mass, -2.7%; and scar mass, -1.2%) and high inter-reader reproducibility (mean bias%: LVEDV, 3.3%; LVESV, 6.2%; LVEF, -4.8%; LV mass, -1.9%; and scar mass, -1.8%). In addition, a high inter-study reproducibility was found (mean bias%: LVEDV, 0.1%; LVESV, -1.8%; LVEF, 1.0%; LV mass, -4.6%; and scar mass, -6.2%).
  
  
  CONCLUSIONS
  Cardiac MR imaging of rats yielded highly reproducible measurements of cardiac volumes/function and myocardial infarct size on a clinical 3.0 Tesla MR scanner system. Consequently, more widely available high field clinical MR scanners can be employed for small animal imaging of the heart e.g. when aiming at serial assessments during therapeutic intervention studies.
authors.affiliation: Department of Cardiology, University Hospital Zurich, Rämistrasse 100, 8091, Zurich, Switzerland. robert.manka@usz.ch.
authors.forename: Robert
authors.initials: R
authors.lastname: Manka
authors.forename: Cosima
authors.initials: C
authors.lastname: Jahnke
authors.forename: Thomas
authors.initials: T
authors.lastname: Hucko
authors.forename: Thore
authors.initials: T
authors.lastname: Dietrich
authors.forename: Rolf
authors.initials: R
authors.lastname: Gebker
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schnackenburg
authors.forename: Kristof
authors.initials: K
authors.lastname: Graf
authors.forename: Ingo
authors.initials: I
authors.lastname: Paetsch
mesh_terms: D000818:Animals; D002921:Cicatrix / Q000473:pathology; D006321:Heart / Q000503:physiopathology*; D006334:Heart Function Tests; D019028:Magnetic Resonance Imaging, Cine / Q000295:instrumentation* / Q000379:methods; D009203:Myocardial Infarction / Q000378:metabolism* / Q000503:physiopathology*; D009206:Myocardium / Q000473:pathology; D015588:Observer Variation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D016277:Ventricular Function, Left