Thesis defense Irati Markuerkiaga (Donders series 369)

25 January 2019

Promotor: prof. dr. D. Norris

On the laminar specificity of BOLD-based cortical activation profiles

The most widely used MR method to assess brain function consists in measuring the gradient echo-based blood oxygenation level dependent signal (GE-BOLD signal). Compared to other methods to measure brain function, GE-BOLD offers several advantages: it has the strongest sensitivity to neuronal activity, it allows to acquire whole brain images in the least amount of time and is available in virtually any MR scanner. The main disadvantage is its poor spatial specificity: signal is smeared as large veins drain blood away from the site of activation. This is, of course, also true for high-resolution GE-BOLD functional MRI aiming at eliciting activation at the level of cortical layers. With one special feature: veins always run perpendicular to the cortical surface, hence signal is smeared only in one direction, from the lower part of the cortex towards the cortical surface.