The threshold contrast thickness evaluated with different CDMAM phantoms and software

The European Commission recommends the CDMAM phantom as a tool to evaluate threshold contrast visibility in digital mammography [1, 2]. The use of the CDMAM phantom for that purpose has been proposed by Young [3] and other researchers. Recently, the phantom has been criticized because of poor reproducibility of the manufacturing process [4, 5], but it is still recommended by the European Commission. According to the manufacturer’s information [6], “(...) during vaporization of the gold disks, the aluminium plate is covered with a mask with lasered holes of the desired diameter. Due to small irregularities of the mask and specifi c deviations related to the vaporization process, the disks can deviate slightly from the intended diameter, and will not be exactly circular. Also the thickness of the disks may deviate from the indicated values, mainly due to the gold vaporization profi le. Thickness at the centre of the phantom tends to be more, and at the edges less than intended (...). Generally, deviations appear to become more signifi cant at smaller disk diameter (up to 5% in area and 10% in diameter). Thickness deviations from indicated values appear to be <10%.” The threshold contrast thickness evaluated with different CDMAM phantoms and software Ewa Fabiszewska, Iwona Grabska, Katarzyna Pasicz