Paola Enrica Colombo, Presenter: Nothing to Disclose

Lorenzo Radici, Abstract Co-Author: Nothing to Disclose

Stefano Pasetto, Abstract Co-Author: Nothing to Disclose

Annalisa Trianni, Abstract Co-Author: Nothing to Disclose

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

Digital Breast Tomosynthesis (DBT) systems have been recently introduced. Limited angular sampling is responsible for ghost artifacts in off-focus planes: an object is visible very far from the in-focus plane. In this work a methodology and special designed phantom for full characterization of DBT artifacts are presented and applied to three commercial systems (Hologic, Siemens, IMS).

The methodology proposed describes the artifacts behaviour in off-focus planes by means of: - artifact punctual propagation in z-direction using the Artifact Spread Function (ASF) (WU (2004)); - integral information of the dishomogeneity produced by artifact evaluating standard deviation of a suitable ROI containing both ghost feature and background. - artifact geometric extension in tube-motion direction by measuring artifact line profiles; A gel phantom containing spherical features of various materials and diameters is developed. Parameters are expressed as function of vertical plane position.  

ASF depends linearly on sphere diameter but not on sphere material (contrast) and it is affected on system’s angular range. The Standard Deviation parameter depends on sphere diameter but also on contrast and the trend is different for the three systems. Profiles extension shows different behaviour for the three systems and doesn’t depend on sphere diameter and contrast.  

ASF, standard deviation of a suitable ROI and profile analysis are an adequate set of measurements to describe artifact behaviour, which depends mainly on systems design.

Artifacts are always visible in Digital Breast Tomosynthesis images. Their extent depend mainly on system design.

Colombo, P, Radici, L, Pasetto, S, Trianni, A, Torresin, A, Artifact Analysis in Digital Breast Tomosynthesis (DBT).  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13044347.html