A database of raw composite mammograms containing simulated microcalcifications was generated. Databases can be used for technology assessment, quality assurance and comparison of different processing algorithms or different visualization modalities in digital mammography. Clinical mammograms were selected and fully documented for this scope. Microcalcifications were simulated in mammography images following a methodology developed and validated in an earlier work of our group. To create microcalcification templates, specimen containing lesions with different morphology types were acquired. From a basic set of (ideal) microcalcification templates, a set of specific templates for the systems under study was generated. The necessary input to do so is the system MTF and attenuation values of aluminum sheets with different thickness. In order to make the whole process less time consuming and applicable on a large scale, dedicated software tools for the creation of composite images have been developed. Automatic analysis of scores from observer performance study, in terms of microcalcification detectability on the composite images, is also implemented. We report on the functionalities foreseen in these new software tools. Simulated microcalcifications were successfully created and inserted in raw images of the Siemens Novation DR, the AGFA DM1000 and the AGFA CR MM2.0.

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The conversion coefficients from air kerma to ICRU operational dose equivalent quantities for STUK's realisation of the X-radiation qualities N-15 to N-60 of the ISO narrow (N) spectrum series were determined by utilising X-ray spectrum measurements. The pulse-height spectra were measured using a planar high-purity germanium spectrometer and unfolded to fluence spectra using Monte Carlo generated data of the spectrometer response. To verify the measuring and unfolding method, the first and second half-value layers and the air kerma rate were calculated from the fluence spectra and compared with the values measured using an ionisation chamber. For each radiation quality, the spectrum was characterised by the parameters given in ISO 4037-1. The conversion coefficients from the air kerma to the ICRU operational quantities Hp(10), Hp(0.07), H'(0.07) and H*(10) were calculated using monoenergetic conversion coefficients at zero angle of incidence. The results are discussed with respect to ISO 4037-4, and compared with published results for low-energy X-ray spectra.