Sensitivity of BOLD and perfusion contrast derived from dual-echo ASL in localising active and imaginary movements

Dual-echo arterial spin labeling (DE-ASL) techniques have been recently proposed for the simultaneous acquisition of ASL and bloodoxygenation-level-dependent (BOLD) fMRI data1. The images acquired at the first echo time are perfusion weighted (ASL), while the images fromthe second echo are primarily T2* weighted, thus sensitive to the BOLD signal2. The sequence is particularly useful when the simultaneousestimation of blood flow and BOLD signal are targeted and moreover, since the separate acquisition of ASL- and BOLD-fMRI scans is no morenecessary, it allows to significantly reduce the scan time3. To the best of our knowledge, the simultaneous comparison of these two sequences is stillunexplored4. The overall aim was to assess the sensitivity of the DE-ASL sequence in comparison to the conventional one (BOLD-fMRI) indetecting brain activations elicited by active and motor imagery hand movements.