Comparison of a scanning MPL-filtered mammography set-up at  keV to a clinical reference system with absorption filtration for a 5 cm breast. The spectral quantum efficiency (SQE) and the relative scan time () are presented for the experimentally obtained spectrum (first row), along with a number of calculated MPL-filtered spectra (subsequent rows) with different focal lengths (), source-to-lens and lens-to-slit distances ( and ), and resolution in the scanning direction (). The parameters of the reference system are shown in the bottom row.