In vivo visualization of the rat central nervous system and cross sectional views of the CST pathway in the sagittal and axial planes. This data were acquired using 3D GE-MEI (a and b) and IR-MEI (c and d). The arrow labeled "SCI" points to the lesion at the T4 level. Thin-rectangles overlaid on the sagittal images represent the slice orientation for the axial images. Arrowhead in a denotes the site of the Mn injection in the brain, where the signal hypointensity is due to the presence of high local concentration of Mn. SI – primary somatosensory cortex, ic – internal capsule, thal – thalamus, cp – cerebral peduncle and py – pyramidal tract.