Rapid multislice T1 mapping of mouse myocardium: Application to quantification of manganese uptake in α-Dystrobrevin knockout mice

Purpose 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 (Mn2+) uptake in a mouse model with altered Ca2+ 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, Mn2+ relaxivity in myocardium, and the impact of Mn2+ on cardiac function. The sensitivity of Mn2+-enhanced MRI in detecting subtle changes in altered Ca2+ 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 Mn2+ dose led to significantly accelerated T1 shortening. Heart rate decreased during Mn2+ 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 Mn2+ uptake in vivo. In vitro patch-clamp study showed increased Ca2+ channel activity. Conclusion The saturation recovery method provides rapid T1 mapping in mouse hearts, which allowed sensitive detection of subtle changes in Mn2+ uptake in α-dystrobrevin knockout mice. Magn Reson Med 74:1370–1379, 2015. © 2014 Wiley Periodicals, Inc.