title: Quantitative image quality measurements of a digital breast tomosynthesis system.
abstract: OBJECTIVE
  The aim of this study was to measure the image quality of a digital breast tomosynthesis (DBT) system quantitatively.
  
  
  METHODS
  The signal transfer property (STP), modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) of the Hologic Selenia Dimensions breast tomosynthesis system were measured according to established methods. The NPS was calculated from two-dimensional (2 D) fast Fourier transform (FFT) of flat field images. The presampling MTF of the system was determined for 2 D standard projection mammography and 3 D breast tomosynthesis mode using the edge method. The DQE was derived for different detector air kerma (DAK) values from NPS and MTF measurements.
  
  
  RESULTS
  The detector response function was linear for both two-dimensional (2 D) standard projection mammography and three-dimensional (3 D) breast tomosynthesis modes. The gradient of the detector response in the 3 D imaging mode was higher than the gradient in the 2 D imaging mode by a factor of 3.1. The MTF values measured at the Nyquist frequency were 32 % and 39 % in 2 D and 3 D imaging modes, respectively. The DQE was saturated at an air kerma value approximately 3.5 times lower in 3 D mode than in 2 D mode. The measured maximum DQE value was 54 %.
  
  
  CONCLUSIONS
  The measured DQE values were comparable with breast tomosynthesis systems from other companies (Siemens, GE).
authors.affiliation: Faculty of Engineering, Department of Engineering Physics, Ankara University, Ankara.
authors.forename: T
authors.initials: T
authors.lastname: Olgar
authors.forename: T
authors.initials: T
authors.lastname: Kahn
authors.forename: D
authors.initials: D
authors.lastname: Gosch
mesh_terms: D000465:Algorithms; D016477:Artifacts; D004867:Equipment Design; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation* / Q000379:methods*; D008327:Mammography / Q000295:instrumentation* / Q000379:methods*; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000295:instrumentation* / Q000379:methods*; D012680:Sensitivity and Specificity