Visualization of the topographical structure of the anesthetized mouse brain by MR microimaging

A nuclear magnetic resonance (NMR) spectrometer equipped with a magnet prod ucing a high and extremely uniform magnetic field (7.05 T) was combined wit h a strong field gradient coil (3.5 mT/cm) and applied to MR microimaging o f the mouse brain to visualize its topograph ic al structure. Since the pro ton-density-weighted condition (long repetition time (TR) and short echo ti me (TE); TR/TE=3,000 ms/10.4 ms) was found to be the most suitable for imag ing the mouse brain, mid-sagittal and coronal sections in 1-mm- or 0.3-mm-t hick slices were imaged according to the multislice spin echo sequence with 2 or 8 acquisitions, a 2 kHz pulse width and a 256 x 256 data matrix. As e xpected, the resolution of MR microimaging was comparable to that of the hi stological sections. The white matter especially, could be distinguished fr om the gray matter in same regions of the brain. Coronal sections of the br ain also showed that the hippocampal CA1-CA3 regions were distinguishable f rom the other regions. The results suggested that the present MR microimagi ng technique might be a useful tool for the study of topological anatomy an d submicroscopic research using brains of small laboratory animals.