Fig. 4.

Tissue contrast comparison with and without an MT pre-pulse for the whole brain MT-3DEPI acquisition (all other imaging parameters were identical, but distinct from the 3DEPI fMRI runs – see Table 1). The MT pre-pulse increased contrast (left) and improved the quality of the GM tissue segmentation as evidenced by the greater overlap between the segmentation, with a GM-probability >0.8, and the cortex as defined by the MP2RAGE data (right column). Examples of substantial improvement are indicated by the yellow arrows, while the blue arrows indicate inaccuracies of GM tissue segmentation in both cases.