Investigation of the microstructure of the isolated rat heart: A comparison between T*2‐ and diffusion‐weighted MRI

Myocardial fiber structure can be determined with diffusion-weighted (DW) MRI as well as with high-resolution T*2 imaging. The purpose of the present study was twofold: to provide a more quantitative description of T*2-based myocardial fiber contrast, and to compare the T*2-based fiber structure with high-resolution (78 μm in-plane, 1-mm slice thickness) DW images of the isolated rat heart at 11.75 T. This study demonstrates that the static dephasing regime is responsible for visualization of myocardial microstructure, and that the dynamic dephasing regime can be neglected. In comparison with DW experiments, T*2 mapping and DW images yield almost equivalent information on myocardial fiber structure. Magn Reson Med 50:1144–1150, 2003. © 2003 Wiley-Liss, Inc.