title: Comparative investigation of the detective quantum efficiency of direct and indirect conversion detector technologies in dedicated breast CT.
abstract: OBJECTIVE
  To investigate the dose saving potential of direct-converting CdTe photon-counting detector technology for dedicated breast CT.
  
  
  METHODS
  We analyzed the modulation transfer function (MTF), the noise power spectrum (NPS) and the detective quantum efficiency (DQE) of two detector technologies, suitable for breast CT (BCT): a flat-panel energy-integrating detector with a 70 μm and a 208 μm thick gadolinium oxysulfide (GOS) and a 150 μm thick cesium iodide (CsI) scintillator and a photon-counting detector with a 1000 μm thick CdTe sensor.
  
  
  RESULTS
  The measurements for GOS scintillator thicknesses of 70 μm and 208 μm delivered 10% pre-sampled MTF values of 6.6 mm(-1) and 3.2 mm(-1), and DQE(0) values of 23% and 61%. The 10% pre-sampled MTF value for the 150 μm thick CsI scintillator 6.9 mm(-1), and the DQE(0) value was 49%. The CdTe sensor reached a 10% pre-sampled MTF value of 8.5 mm(-1) and a DQE(0) value of 85%.
  
  
  CONCLUSIONS
  The photon-counting CdTe detector technology allows for significant dose reduction compared to the energy-integrating scintillation detector technology used in BCT today. Our comparative evaluation indicates that a high potential dose saving may be possible for BCT by using CdTe detectors, without loss of spatial resolution.
authors.affiliation: Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Henkestraße 91, 91052 Erlangen, Germany.
authors.forename: Jan D
authors.initials: JD
authors.lastname: Kuttig
authors.affiliation: Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Henkestraße 91, 91052 Erlangen, Germany; CT Imaging GmbH, Henkestraße 91, 91052 Erlangen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Steiding
authors.affiliation: Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Henkestraße 91, 91052 Erlangen, Germany; CT Imaging GmbH, Henkestraße 91, 91052 Erlangen, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kolditz
authors.affiliation: Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Henkestraße 91, 91052 Erlangen, Germany; CT Imaging GmbH, Henkestraße 91, 91052 Erlangen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Hupfer
authors.affiliation: Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Henkestraße 91, 91052 Erlangen, Germany.
authors.forename: Marek
authors.initials: M
authors.lastname: Karolczak
authors.affiliation: Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Henkestraße 91, 91052 Erlangen, Germany; CT Imaging GmbH, Henkestraße 91, 91052 Erlangen, Germany. Electronic address: willi.kalender@imp.uni-erlangen.de.
authors.forename: Willi A
authors.initials: WA
authors.lastname: Kalender
mesh_terms: D001940:Breast; D019187:Cadmium Compounds; D008327:Mammography / Q000295:instrumentation*; D011829:Radiation Dosage; D012588:Scintillation Counting / Q000295:instrumentation*; D059629:Signal-To-Noise Ratio; D013691:Tellurium
chemical_list: D019187:Cadmium Compounds; D013691:Tellurium; C028337:cadmium telluride
keywords: Cadmium telluride detector technology; Detective quantum efficiency; Modulation transfer function; Noise power spectrum