In recent years several new digital mammography equipments with different innovative features have been proposed on the market [1,
The work compares 7 different so called direct radiography (DR) models with respect to physical characteristics,
phantom image quality and dose.
Methods and Materials
This work covers most of the innovations.
It embraces 8 direct radiography (DR) systems of 7 different models and 5 different manufacturers; 2 computed radiography (CR) systems are reported for comparison (list in Fig.
System A1 and A2 are twin systems which underwent an x-ray tube replacement in 2010; Systems A3 and A4 are identical apart from the detector technology (Fig.3 and 4).
Data of SystemD1 arepreliminary. The technological innovations introduced are related to 3 different...
Physical characterisation: General comparison between CR and DR systems and between direct and indirect conversion technology in DR systems: Figures 1,
2 and 3 show for several systems the frequency dependence of the parameters MTF,
NNPS and DQE,
up to the Nyquist frequency. DR units clearly outperformed CR systems. Direct conversion flat panels (a-Se,
systems A1-A4) exhibited a higher MTF than detectors based on indirect conversion with needle-like CsI (systems B1,
DQE of all DR systems ranked between 55% and 80%,
being higher in systems using adetectorbased on direct conversion and newer detector technology.
a higher DQE traduced into a higher image quality expressed as IQF inv score.
Target/filter combinations producing spectra of higher mean energy confirmed better performances than conventional Mo/Mo ones.
The innovative photoconductive switching readout exhibited a potential average dose saving of 20% compared to state of the flat panels...
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A technical report” (2006) Young,
“Technical Evaluation of Fuji Amulet Full Field Digital Mammography System”,
NHSBSP Equipment Report 0907 (2009),
“X-ray spectrum optimization of full-field digital mammography: Simulation and phantom study”,
4337-4349 (2006) Baldelli,
Nadia Oberhofer Medical Physicist at Azienda Sanitaria dell'Alto Adige Ospedale di Bolzano Via L.
Böhler 5 39100 Bolzano (Italy) email: firstname.lastname@example.org Tel.