Quantitative image quality measurements of a digital breast tomosynthesis system

Abstract

Purpose: The aim of this study was to measure the image quality of a digital breast tomosynthesis (DBT) system quantitatively. Materials and 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 (2D) fast Fourier transform (FFT) of flat field images. The presampling MTF of the system was determined for 2D standard projection mammography and 3D 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 (2D) standard projection mammography and three-dimensional (3D) breast tomosynthesis modes. The gradient of the detector response in the 3D imaging mode was higher than the gradient in the 2D imaging mode by a factor of 3.1. The MTF values measured at the Nyquist frequency were 32% and 39% in 2D and 3D imaging modes, respectively. The DQE was saturated at an air kerma value approximately 3.5 times lower in 3D mode than in 2D mode. The measured maximum DQE value was 54%. Conclusion: The measured DQE values were comparable with breast tomosynthesis systems from other companies (Siemens, GE). Citation Format: Olgar T, Kahn T, Gosch D. Quantitative Image Quality Measurements of a Digital Breast Tomosynthesis System. Fortschr Röntgenstr 2013; 185: 1188-1194. © Georg Thieme Verlag KG Stuttgart.