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Physical characteristics of GE Senographe Essential and DS digital mammography detectors
Author(s) -
Ghetti Caterina,
Borrini Adriano,
Ortenzia Ornella,
Rossi Raffaella,
Ordóñez Pedro L.
Publication year - 2008
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.2828185
Subject(s) - mammography , digital mammography , medical physics , detector , medicine , physics , nuclear medicine , optics , breast cancer , cancer
The purpose of this study was to investigate physical characteristics of two full field digital mammography (FFDM) systems (GE Senographe Essential and DS). Both are indirect conversion (x ray to light) a ‐ Si flat panels coupled with a CsI(Tl) scintillator. The examined systems have the same pixel size( 100 μ m )but a different field of view: a conventional size 23 × 19.2cm 2and a large field 24 × 30.7cm 2 , specifically designed to image large breasts. In the GE Senographe Essential model relevant improvements in flat panel design were implemented and new deposition tools for metal, a ‐ Si , and CsI(Tl) were introduced by GE. These changes in detector design are expected to be beneficial for advanced applications such as breast tomosynthesis. The presampling modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were measured for a wide range of exposure( 25 – 240 μ Gy )with a RQA‐M2 technique (28 kVp with a Mo/Mo target/filter combination and 2 mm of additional aluminum filtration). At 1, 2, and at 4 lp/mm MTF is equal to 0.9, 0.76, and 0.46 for the conventional field detector and to 0.85, 0.59, and 0.24 for the large field detector. The latter detector exhibits an improved NNPS due to a lower electronic noise and a better DQE that reaches 60 % . In addition a contrast‐detail analysis was performed with CDMAM 3.4 phantom and CDCOM software: GE Senographe DS showed statistically significant poorer detection ability in comparison with the GE Senographe Essential. These results could have been expected, at least qualitatively, considering the relative DQE of the two systems.