Effect of Different Breast Densities and Average Glandular Dose on Contrast to Noise Ratios in Full-Field Digital Mammography: Simulation and Phantom Study
Table 1
CNR values based on mammary gland density and imaging conditions.
Fibroglandular adipose mass (%)
Thickness of phantom (mm)
Target filter
Tube voltage (kV)
mAs (mAs)
AGD (mGy)
CNR
Phantom A (30/70)
10
Mo/Mo
26
16.7
0.48
23.1
20
26
27.9
0.75
20.1
30
Mo/Rh
27
41.7
1.01
16.2
40
28
57.1
1.27
15.1
50
Rh/Rh
29
60.8
1.33
13.0
60
29
74.9
1.58
11.7
70
30
90.2
1.95
10.9
Phantom B (50/50)
10
Mo/Mo
26
18
0.53
21.8
20
26
34
0.85
20.8
30
Mo/Rh
27
47.2
1.07
16.0
40
Rh/Rh
29
50.1
1.2
13.7
50
30
52.4
1.23
11.4
60
31
59.7
1.49
9.6
70
30
75
1.47
8.4
Phantom C (70/30)
10
Mo/Mo
26
19.1
0.54
21.8
20
26
37.8
0.87
19.1
30
Mo/Rh
27
44
0.9
13.8
40
Rh/Rh
29
59.7
1.23
12.6
50
30
69
1.55
10.6
60
30
64
1.29
9.0
70
30
95.3
1.73
8.1
AGD: average glandular dose, CNR: contrast to noise ratio, Mo: molybdenum, and Rh: rhodium.