First validation of a new phantom for global quality control in digital mammography

As part of an EC funded project, the design for a new phantom has been proposed that consists of a smaller contrast-detail part than the CDMAM phantom and that contains items for other parts of an acceptance protocol for digital mammography. A first prototype of the "DIGIMAM" has been produced. Both the CDMAM phantom and the DIGIMAM phantom were then used on a series of systems and read out as a part of a multi centre study. The results with the new phantom were very similar to results obtained with the CDMAM phantom: readers scored different from each other and there was an overlap in the scores for the different systems, A system with a poor score in CDMAM had also the worst score for DIGIMAM. Reading time was significantly reduced however. There was promising agreement between automated reading of CDMAM and the scores of the DIGIMAM phantom. In order to reduce the subjectivity of the readings, computerized reading of the DIGIMAM should be developed. In a second version of the phantom, we propose to add more disks of the same size and contrast in each square to improve the statistical power of each reading.