While the above mentioned advancements of VASO imaging can account for erstwhile shortcomings of imaging coverage and resolution, they do not account for other potential limitations. As such, it has been previously suggested that the VASO signal, can contain an unwanted sensitivity to potential dynamic changes in CSF volume (Donahue et al. 2006; Jin and Kim 2010; Lu et al. 2013; Scouten and Constable 2007). Thus, when strong global tasks are used (E.g., CO2 respiration challenges; hypercapnia) during which sulcal CSF volume is significantly affected, their influence on the VASO signal need to be accounted for. Most popular strategies involve, a) TR-matching for similar GM and CSF contrast (Huber et al. 2015), b) double inversion (Donahue et al. 2006), c) or repeating the experiments with multiple T1-weighting strengths (Scouten and Constable 2007).
