The GRE-BOLD contrast used in laminar fMRI suffers from suboptimal specificity due to extravascular effects around large veins. CBV-weighting offers improved specificity with signal changes being more confined to microvasculature. CBV-weighting can be achieved through saturation of gray matter signal with magnetization transfer. We use a multi-echo FLASH sequence at 7 Tesla, with and without MT preparation to investigate its feasibility at ultrahigh field. We analyze the TE dependence to determine when the BOLD T2’-effects start to dominate the MT-weighted signal changes. The MTprep profiles exhibit a stronger signal change in gray matter at short TEs and reduced extravascular effects.
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