Keywords:
Quality assurance, Acceptance testing, Mammography, Radiation physics
Authors:
S. Bara, A. Petropoulos, S. Skiadopoulos, G. Vlachopoulos, A. Karahaliou, G. A. T. Messaris, L. Costaridou; Patras/GR
DOI:
10.26044/ecr2019/C-2595
Results
Mass SDNR:
As observed in Fig.
9,
both mass SDNR definitions demonstrate small differences,
especially in case of BT for all mass contrast values studied.
However,
testing of performances obtained by the two (2) mass SDNR definitions per mammographic mode (Table 2),
no statistically significant differences were verified (two-tailed Wilcoxon Signed Ranks test for paired data,
p>0.05).
Fig. 9: Comparison of the two (2) mass SDNR definitions utilized for all masses M1 to M5 (nominal contrast values of 4%, 3%, 2%, 1.5% and 1%, respectively), for DM and BT modes at 45 mm PMMA thickness.
Table 2: Results of Wilcoxon signed ranks test for the two (2) mass SDNR definitions utilized for DM and BT modes.
MC cluster SDNR:
As observed in Fig.
10,
the two MC cluster definitions of SDNR demonstrate some differences,
both in DM and BT modes.
However,
testing of performances obtained by the two (2) MC cluster SDNR definitions per mammographic mode (Table 3),
statistically significant differences were identified for the three (3) largest in size MC clusters for DM and the largest MC cluster for BT (two-tailed Wilcoxon Signed Ranks test for paired data,
p<0.05).
Fig. 10: Comparison of the two (2) MC cluster SDNR definitions utilized, for all microcalcification clusters of the following sizes (upper and lower particle size limit of each cluster: MC1: 354-224 μm, MC2: 283-180 μm, MC3: 226-150 μm, MC4: 177-106 μm), for DM and BT modes at 45 mm PMMA thickness.
Table 3: Results of Wilcoxon signed ranks test for the comparison of the two (2) definitions utilized for microcalcification clusters, in DM and BT modes.