Fig 1: Fuzzy Ripples are the reason why layer-fMRI is confined to conventional protocols.

Fuzzy Ripples are the primary reason why layer-fMRI is restricted to conventional protocols. Standard layer-fMRI protocols are generally limited to 0.8mm resolution with TRs of several seconds, focusing on upper cortical brain areas. These limitations cannot be surpassed because, with more ambitious acquisition protocols. Fuzzy Ripple artifacts become too strong and too frequent. Panel A) exemplifies issues of pushing TR. Panel B) exemplifies issues of pushing resolutions beyond 0.8mm. Panel C) exemplifies issues of pushing protocols towards lower brain areas. Images from Panels A and B are taken from Koiso 2023 and Huber 2023, respectively. They refer to 3D-EPI readouts with planar EPI trajectories.