Francis R. Verdun PhD, Presenter: Nothing to Disclose

Pascal Monnin, Abstract Co-Author: Nothing to Disclose

Nicholas Marshall, Abstract Co-Author: Nothing to Disclose

Hilde Bosmans PhD, Abstract Co-Author: Research grant, Siemens AG

To validate a non-prewhitened model observer with eye filter (NPWE) as an alternative performance indicator for contrast-detail measurements.

The objective image quality metrics of contrast, modulation transfer function (MTF), and normalized noise power spectrum (NNPS) were measured on 11 different digital mammography systems and used to calculate the detectability index (d') of a NPWE model observer. The d' calculations were made over detector air kerma values ranging from 12 to 400 μGy; CDMAM phantom images were then acquired over the same detector air kerma range for the purpose of validation. Threshold gold thickness (contrast) for 0.10 and 0.25 mm diameter details was obtained from automated scoring of CDMAM using CDCOM and Erica2 software and a relationship between d' and threshold gold thickness established.

Excellent correlation was found between d’ values and threshold gold thicknesses for 0.10 and 0.25 mm details for the group of 11 systems. The Acceptable levels given in the European Guidelines for the 0.10 and 0.25 mm details corresponded to target d’ values of 1.05 and 6.30, respectively, with an uncertainty within ± 10%.

The use of d’ is a promising alternative method for contrast-detail analysis that can be easily included in routine quality assurance controls.

Rapid and robust estimates of image quality for minimum performance specification and quality assurance of digital x-ray systems used for screening mammography.

Verdun, F, Monnin, P, Marshall, N, Bosmans, H, The NPWE Model Observer as an Alternative Performance Indicator for Contrast Detail Measurements in Digital Mammography.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034457.html