Investigating Activation Dependence on Cortical Depth and TE Using 2D FLASH

Rosa Maria Sanchez Panchuelo¹, Jack Harmer¹, Richard Bowtell¹, Susan Francis¹

Here we examine the echo time dependence of the cortical depth-related grey matter GE BOLD signal change in visual cortex using high resolution (0.35x0.35x1.5 mm3) 2D FLASH imaging at 7 T. A linear dependence of the average fractional signal change with echo time was found for all bands defined across the cortex. There was a reduction in δR2* on moving from the pial surface (1.50.1)s-1 to the border with white matter (0.590.05)s-1, and no evidence of increased δR2* in the stria of Gennari. In contrast, the measured R2* showed a clear peak in the stria of Gennari.