Fig. 9. Factors that influence the extent of streaming in an in vitro model of human cerebral arteries. A shows streaming of the dye (2 ml/min) from a P-100 catheter in a supraophthalmic position (bold vertical arrow ). Note that there is a clear stream of dye in the anterior choroidal artery (Ach A) and that there is no flow of the dye to the anterior cerebral artery (ACA). B shows a more homogeneous dispersion of the dye when it is injected in an infraophthalmic location at a rate of 17 ml/min. A proximal site and a high rate volume rate of infusion, decrease the variability in drug concentration due to streaming. From Lutz et al. 107; used with permission.