Phase Contrast in the Post Mortem Rat Brain: Comparison with T2* and Histology

Ana Maria Oros-Peusquens¹, Sebastian Hirsch¹, Joerg Felder¹, Avdo Celik¹, M Cremer¹, N. Jon Shah¹

The origins of phase contrast were investigated in a post mortem rat brain with high isotropic resolution (60m) MRI. The phase contrast after formalin fixation was characterised in the whole brain and compared with T2* maps and cellular structure based on histology. Phase images acquired on a post mortem rat brain allow for a more complete visualisation of fine layers in the hippocampus and with higher contrast (factor 10-20) than with magnitude images alone. For hippocampal structures myelin and iron content are not the main contrast-generating factor. Instead, the phase contrast seems more correlated with the cell density as described by the intensity of Nissl staining in histology.