Rapid T 2 mapping of mouse heart using the carr–purcell–meiboom–gill sequence and compressed sensing reconstruction

Purpose To develop and prove preliminary validation of a fast in vivo T 2 mapping technique for mouse heart. Materials and Methods Magnetic resonance imaging (MRI) experiments were performed on a 7T animal scanner. The standard Carr–Purcell–Meiboom–Gill (CPMG) sequence was modified to minimize the effect of stimulated echoes for accurate T 2 quantification. The acquisition was further accelerated with the compressed sensing approach. The accuracy of the proposed method was first validated with both phantom experiments and numerical simulations. In vivo T 2 measurement was performed on seven mice in a manganese‐enhanced MRI study. Results In phantom studies, T 2 values obtained with the modified CPMG sequence are in good agreement with the standard spin‐echo method ( P > 0.05). Numerical simulations further demonstrated that with the application of the compressed sensing approach, fast T 2 quantification with a spatial resolution of 2.3 mm can be achieved at a high temporal resolution of 1 minute per slice. With the proposed technique, an average T 2 value of 25 msec was observed for mouse heart at 7T and this number decreased significantly after manganese infusion ( P < 0.001). Conclusion A rapid T 2 mapping technique was developed and assessed, which allows accurate T 2 quantification of mouse heart at a temporal resolution of 1 minute per slice. J. Magn. Reson. Imaging 2016;44:375–382.