title: Quantitative T2 mapping of the mouse heart by segmented MLEV phase-cycled T2 preparation.
abstract: OBJECTIVE
  A high-quality, reproducible, multi-slice T2-mapping protocol for the mouse heart is presented.
  
  
  METHODS
  A T2-prepared sequence with composite 90° and 180° radiofrequency pulses in a segmented MLEV phase cycling scheme was developed. The T2-mapping protocol was optimized using simulations and evaluated with phantoms.
  
  
  RESULTS
  Repeatability for determination of myocardial T2 values was assessed in vivo in n = 5 healthy mice on 2 different days. The average baseline T2 of the left ventricular myocardium was 22.5 ± 1.7 ms. The repeatability coefficient for R2 = 1/T2 for measurements at different days was ΔR2 = 6.3 s(−1). Subsequently, T2 mapping was applied in comparison to late-gadolinium-enhancement (LGE) imaging, to assess 1-day-old ischemia/reperfusion (IR) myocardial injury in n = 8 mice. T2 in the infarcts was significantly higher than in remote tissue, whereas remote tissue was not significantly different from baseline. Infarct sizes based on T2 versus LGE showed strong correlation. To assess the time-course of T2 changes in the infarcts, T2 mapping was performed at day 1, 3, and 7 after IR injury in a separate group of mice (n = 16). T2 was highest at day 3, in agreement with the expected time course of edema formation and resolution after myocardial infarction.
  
  
  CONCLUSIONS
  T2 prepared imaging provides high quality reproducible T2 maps of healthy and diseased mouse myocardium.
authors.forename: Bram F
authors.initials: BF
authors.lastname: Coolen
authors.forename: Frank F J
authors.initials: FF
authors.lastname: Simonis
authors.forename: Tessa
authors.initials: T
authors.lastname: Geelen
authors.forename: Rik P M
authors.initials: RP
authors.lastname: Moonen
authors.forename: Fatih
authors.initials: F
authors.lastname: Arslan
authors.forename: Leonie E M
authors.initials: LE
authors.lastname: Paulis
authors.forename: Klaas
authors.initials: K
authors.lastname: Nicolay
authors.forename: Gustav J
authors.initials: GJ
authors.lastname: Strijkers
mesh_terms: D000465:Algorithms; D000818:Animals; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D009203:Myocardial Infarction / Q000473:pathology*; D009206:Myocardium / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted