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ST: Fachverband Strahlen- und Medizinphysik

ST 5: Imaging with Ionizing Radiation I

ST 5.3: Vortrag

Donnerstag, 17. März 2011, 10:30–10:45, POT 112

Direct signal-to-noise comparison of radiographic attenuation- and differential phase-contrast X-ray images — •Dieter Hahn, Pierre Thibault, Martin Bech, and Franz Pfeiffer — Department of Physics (E17) and Institute of Medical Engineering (IMETUM), Technische Universität München, Germany

For radiographic applications of X-ray differential phase-contrast imaging, like e.g. mammography, we present the Relative Contrast Gain (RCG) as a novel measure of the relative information content of attenuation- and differential phase-contrast (dpc) radiographs recorded with a grating-based Talbot interferometer. It is a fast and simple method to quantify the gain in soft-tissue contrast of the differential phase-contrast signal compared to the standard attenuation based radiograph. The RCG can also be used as a figure of merit to assess the quality of different experimental setups in terms of providing good feature visibility in soft-tissue samples in the presence of noise. A comparison of a differential signal to a non-differential signal is achieved by analysis of the calculated gradient of the attenuation signal. The Relative Contrast Gain analysis is applied on experimental absorption and phase-contrast projections obtained for human breast samples. The results show a good gain in feature contrast in the dpc signal compared to the attenuation signal as expected from theory.