The two-dimensional angular correlation of electron-positron annihilation radiation (2D ACAR) from the heavy-fermion dense Kondo system CeB₆ was measured. The anisotropies of the measured momentum spectra were in reasonable agreement with those of model spectra based on the Fermi-surface topology suggested by band-structure calculations and de Haas-van Alphen measurements. However, the related k-space densities, obtained by an LCW analysis, were far removed from those expected from the Fermi-surface topology. The use of a recently developed filter procedure, designed to remove the characteristic long-range distortions that are frequently encountered in such LCW spectra, provided a much improved image of the Fermi-surface features.