Table 3: The subjective scores of LCD.

Tube voltage/tube current-time productSubjective score of LCDMean 𝑃 value*
Observer AObserver B

80 kV/150 mAs3.0 (1.0, 1.0, 1.0)3.0 (1.0, 1.0, 1.0) 1 . 0 0 ± 0 . 0 0 0.001
80 kV/200 mAs3.0 (1.0, 1.0, 1.0)3.0 (1.0, 1.0, 1.0) 1 . 0 0 ± 0 . 0 0 0.001
80 kV/250 mAs3.0 (1.0, 1.0, 1.0)3.0 (1.0, 1.0, 1.0) 1 . 0 0 ± 0 . 0 0 0.001
80 kV/300 mAs5.0 (1.0, 2.0, 2.0)6.0 (2.0, 2.0, 2.0) 1 . 8 3 ± 0 . 4 1 0.001
80 kV/350 mAs6.0 (2.0, 2.0, 2.0)6.0 (2.0, 2.0, 2.0) 2 . 0 0 ± 0 . 0 0 0.001
80 kV/400 mAs7.0 (2.0, 3.0, 2.0)7.0 (2.0, 3.0, 2.0) 2 . 3 3 ± 0 . 5 2 0.019
80 kV/450 mAs7.0 (3.0, 2.0, 2.0)7.0 (2.0, 2.0, 3.0) 2 . 3 3 ± 0 . 5 2 0.019
80 kV/500 mAs8.0 (2.0, 3.0, 3.0)6.0 (2.0, 2.0, 2.0) 2 . 3 3 ± 0 . 5 2 0.019
80 kV/550 mAs8.0 (3.0, 3.0, 2.0)8.0 (3.0, 2.0,3.0) 2 . 6 7 ± 0 . 5 2 0.138
80 kV/600 mAs9.0 (3.0, 3.0, 3.0)8.0 (2.0, 3.0, 3.0) 2 . 8 3 ± 0 . 4 1 0.317
80 kV/650 mAs9.0 (3.0, 3.0, 3.0)9.0 (3.0, 3.0, 3.0) 3 . 0 0 ± 0 . 0 0 1.000
120 kV/300 mAs9.0 (3.0, 3.0, 3.0)9.0 (3.0, 3.0, 3.0) 3 . 0 0 ± 0 . 0 0

*The 𝑃 values are those obtained with 80 kV at the 150–650 mAs settings compared with the values obtained with 120 kV and 300 mAs. There was good agreement between observer A and observer B in regard to subjective assessment of LCD ( 𝜅 = 0 . 6 7 ).