This is the experiments where labelling efficiency was modulated data set from the work 'Non-invasive MRI of Blood-Cerebrospinal Fluid Barrier Function' (Evans et al., 2020, Figure 1F &G].The experiments were designed to ensure there was negligible intra-vascular signal contributions from the BCSFB-ASL signal.The data is in Matlab format. The BCSFB-ASL data is in a 4D array where the first two array elements are the 2D MRI images, the 3rd element is the interleaved tagged and control images (inner most loop) together with the B0 and diffusion weighted images (b=200 s/mm2) together with the number of repetitions (outer most loop, 20 repetitions) and the 4th element is the number of inflow times (750, 2750 and 6500 ms).The traditional ASL data is in the same format but there is only 1 inflow time (750ms) and 5 rather then 20