Enrico De Vita1,2, David L. Thomas2,3, Matthias Gnther4,5, Xavier Golay1,3
1Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, United Kingdom; 2Medical Physics and Bioengineering, University College London, London, United Kingdom; 3Institute of Neurology, University College London, London, United Kingdom; 4Mediri GmbH, Heidelberg, Germany; 5Fraunhofer MEVIS-Institute for Medical Image Computing, Bremen, Germany
In arterial spin labelling (ASL) acquisitions, multiple post-labelling delays (TI) are often used to quantify cerebral blood flow (CBF) without the potential errors associated with assumptions on bolus arrival time. Q2TIPS saturation is often additionally used to precisely define the temporal width of the tagged bolus and facilitate CBF estimation. However the Q2TIPS pulse train modifies tissue and blood signal via magnetisation transfer effects. Here, we examine this undesired effect in multi-TI ASL with 3D-GRASE, in particular how it alters the effectiveness of background suppression of static tissue and therefore impacts on the SNR of the ASL measurement.