4-dimensional local radial basis function interpolation of large, uniformly spaced datasets

•sparse data from MRI velocimetry can be interpolated using radial basis functions.•the interpolation is in time as well as 3D space.•sparse data in the cerebrospinal fluid spaces in the cerebral hemispheres is interpolated.•the velocity field after interpolation has twice as many data points.•this velocity field may be useful for further modelling of cerebrospinal fluid for drug delivery.