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Table 5 The 34/66 calibration mixture example # 1

From: Effective radiation attenuation calibration for breast density: compression thickness influences and correction

34/66 calibration # 1
ts/t (cm) 5.9/6.4 5.0/5.5 4.4/4.9 3.8/4.3 3.4/4.0
Compression
force (dN)
0.0 4.0 5.0 6.0 8.0
PG (5%) 36.3 (1.1) 35.5(0.5) 35.6 (0.4) 35.6(0.4) 32.5 (0.4)
PGs (47%) 47.3(0.7) 49.2(0.6) 50.7(0.8) 52.5(1.0) 50.7(1.2)
PGs+5 (6%) 35.7(0.7) 36.4(0.6) 37.6(0.9) 37.7(0.9) 35.1 (1.1)
PGΔ (10%) 38.5(0.5) 37.9(0.4) 38.2(0.4) 38.4(0.4) 35.1(0.5)
  1. The percent glandular (PG) row gives the means and standard deviations (parenthetical entries) for the calibrated pixel value distribution for the region shown in Figure 12 (right) for various sample thicknesses and compression forces by first applying the thickness correction. The PGs row gives the calibration results for the same region using the system thickness readout (no correction), and the PGs+5 row gives the calibration results by adding 0.5 cm to the system thickness readout value (simple static correction). The PGΔ gives the perturbed calibration by subtracting 1 mm from the corrected thickness in the calibration to assess the limits of the correction. The top row gives the system readout thickness/average corrected thickness (ts/t) values. The parenthetical entries in the first column are the relative difference = | PG m PG known | PG known × 100 % averages taken over the respective row, where PGm is one of the four measured quantities and PGknown is the known mixture composition.