Table 3. SNR and CTDIvol at Different Tube Voltages (n = 24).

kVp	AI (mean ± SD)		P*	CTDIvol (mGy)
	Non-O-MAR	O-MAR
140	4.17 ± 1.24	5.07 ± 1.34	0.008	11.6
120	3.65 ± 1.04	4.48 ± 1.23	0.003	7.9
100	3.10 ± 0.79	4.07 ± 1.18	< 0.001	4.7
80	2.41 ± 0.60	3.21 ± 0.95	< 0.001	2.3

^*Comparison of SNR between paired O-MAR and non-O-MAR images. CTDIvol = volume CT dose index, O-MAR = orthopedic metal artifact reduction, SNR = signal-to-noise ratio