Research Article
Image Quality of Digital Direct Flat-Panel Mammography Versus an Indirect Small-Field CCD Technique Using a High-Contrast Phantom
Table 1
Correct notations by the 4 raters for all quadrants on the 48 transparent films (768 observations per imaging technique).
| (a) Correct notations as a function of the number of silica beads |
| | Gold standard: number of silica beads [class] | Number of correct ratings [ (%)] | Quadrants rated [ (%)] | | Digital Mammography | 1024 CCD | 512 CCD |
| | 0 | 131 (83.97) | 143 (91.67) | 152 (97.44) | 156 (100.0) | | 1–4 | 13 (54.17) | 12 (50.00) | 11 (45.83) | 24 (100.0) | | 5–9 | 92 (63.89) | 102 (70.83) | 95 (65.97) | 144 (100.0) | | 10–19 | 160 (62.50) | 161 (62.89) | 164 (64.06) | 256 (100.0) | | 20–39 | 26 (36.11) | 30 (241.67) | 23 (31.94) | 72 (100.0) | | 40+ | 31 (27.68) | 26 (23.21) | 19 (16.96) | 112 (100.0) |
| | Total | 453 (59.29) | 474 (62.04) | 464 (60.73) | 764 (100.0) |
| | Kappa | 0.49 | 0.52 | 0.50 | | | ( value) | .0001 | .0001 | .0001 | |
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| (b) Correct mentions as a function of size |
| | Gold standard: diameters of the silica beads [m] | Number of correct ratings [ (%)] | Quadrants rated [ (%)] | | Digital Mammography | 1024 CCD | 512 CCD |
| | 0 | 118 (62.77) | 108 (57.45) | 82 (44.62) | 188 (100.0) | | 100–199 | 88 (64.71) | 88 (64.71) | 68 (50.00) | 136 (100.0) | | 200–399 | 153 (78.06) | 156 (79.59) | 138 (70.41) | 196 (100.0) | | 400–599 | 81 (88.04) | 78 (84.78) | 75 (81.52) | 92 (100.0) | | 600+ | 131 (83.97) | 143 (91.67) | 152 (1897.44) | 156 (100.0) |
| | Total | 571 (74.35) | 573 (74.61) | 515 (67.06) | 768 (100.0) |
| | Kappa | 0.68 | 0.68 | 0.59 | | | ( value) | (.0001) | (.0001) | (.0001) | |
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