title: Rapid multislice T1 mapping of mouse myocardium: Application to quantification of manganese uptake in α-Dystrobrevin knockout mice.
abstract: OBJECTIVE
  The aim of this study was to develop a rapid, multislice cardiac T1 mapping method in mice and to apply the method to quantify manganese (Mn(2+)) uptake in a mouse model with altered Ca(2+) channel activity.
  
  
  METHODS
  An electrocardiography-triggered multislice saturation-recovery Look-Locker method was developed and validated both in vitro and in vivo. A two-dose study was performed to investigate the kinetics of T1 shortening, Mn(2+) relaxivity in myocardium, and the impact of Mn(2+) on cardiac function. The sensitivity of Mn(2+)-enhanced MRI in detecting subtle changes in altered Ca(2+) channel activity was evaluated in a mouse model with α-dystrobrevin knockout.
  
  
  RESULTS
  Validation studies showed strong agreement between the current method and an established method. High Mn(2+) dose led to significantly accelerated T1 shortening. Heart rate decreased during Mn(2+) infusion, while ejection ratio increased slightly at the end of imaging protocol. No statistical difference in cardiac function was detected between the two dose groups. Mice with α-dystrobrevin knockout showed enhanced Mn(2+) uptake in vivo. In vitro patch-clamp study showed increased Ca(2+) channel activity.
  
  
  CONCLUSIONS
  The saturation recovery method provides rapid T1 mapping in mouse hearts, which allowed sensitive detection of subtle changes in Mn(2+) uptake in α-dystrobrevin knockout mice.
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Jiang
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Wen
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Sen
authors.initials: S
authors.lastname: Jiao
authors.affiliation: Department of Molecular Cardiology, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Laurie
authors.initials: L
authors.lastname: Castel
authors.affiliation: Department of Molecular Cardiology, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Van Wagoner
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.|Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA.|Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Yu
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D057791:Cardiac Imaging Techniques / Q000379:methods*; D049029:Dystrophin-Associated Proteins / Q000235:genetics* / Q000378:metabolism; D006321:Heart / Q000033:anatomy & histology / Q000502:physiology; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008345:Manganese / Q000493:pharmacokinetics*; D051379:Mice; D018345:Mice, Knockout; D019047:Phantoms, Imaging
chemical_list: D049029:Dystrophin-Associated Proteins; C098885:dystrobrevin; D008345:Manganese; D002118:Calcium
keywords: Ca2+ channel activity; Mn2+ relaxivity; T1 mapping; manganese-enhanced MRI; nNOS; α-dystrobrevin knockout mouse