Paola Enrica Colombo, Abstract Co-Author: Nothing to Disclose

Daniela Origgi PhD, Presenter: Nothing to Disclose

Arcangela Maldera, Abstract Co-Author: Nothing to Disclose

Paolo De Marco, Abstract Co-Author: Nothing to Disclose

Mauro Campoleoni BS, Abstract Co-Author: Nothing to Disclose

Alberto Torresin PhD, Abstract Co-Author: Nothing to Disclose

Digital Breast Tomosynthesis (DBT) is a recently introduced technique for the detection of breast cancer. The aim of this work is to give a physical characterization of three commercial systems in order to evaluate their performances in the clinical practice.

The systems investigated are Senograph Essential GE, Mammomat Inspiration Siemens and Selenia Dimensions Hologic. They use different angular ranges (15°-50°), projection numbers (9-25), types of acquisition (step and shoot-continuous) and reconstruction algorithms (FBP – Iterative (IR)). Average Glandular Dose (AGD) and image quality parameters were taken into account. AGD was estimated with a calibrated ionization chamber according to the Dance model. Image quality parameters of 3D images include signal and noise uniformity, modulation transfer function (MTF, Zhao 2008) and contrast to noise ratio (CNR). The artefacts were investigated measuring the Artefact Spread Function (ASF, Wu 2004) of spherical details of various materials and diameters, while the effective reconstructed plane thickness was evaluated using a thin tilted wire.  

Measured AGD is always under acceptable limits established for FFDM (EC 2006). Signal and noise uniformity are better than 95% for the three systems. For all the systems MTF is different in the front-back (FB) and left-right (LR) directions, showing a better result in the FB one. The MTF50% in the movement LR direction is 3.2 lp/mm for GE and 1.3 lp/mm for the others. The better resolution of GE could be due to the acquisition modality. As expected, ASF depends on detail dimension for all the systems; the persistency of the artefacts away from the in-focus plane is larger for smaller range systems. CNR depends also on reconstruction process and it is higher for GE probably due to the IR algorithm used. Effective thickness of the reconstructed planes depends on angular range: the slice thickness increases for smaller angular values.  

Physical characterization of DBT systems is important to evaluate dose and to determine image quality parameters, which can influence clinical detectability of pathological tissues.

Dose and image quality assessment are important in clinical practice because they affect the insight of the radiologists. However, these parameters are deeply influenced by the system design.

Colombo, P, Origgi, D, Maldera, A, De Marco, P, Campoleoni, M, Torresin, A, Performance Evaluation of Different DBT Systems: Dose and Image Quality Assessment.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14010806.html