Table 4. Overall objective image quality for every scan protocol and kV setting.

Scan parameter					p-value
High pitch (n = 81)	Overall	70 kV	80 kV	90 kV
Coronary attenuation (HU)	367 ± 43	378 ± 48	358 ± 37	360 ± 38	0.141
Image noise	43 ± 6	43 ± 7	42 ± 6	45 ± 7	0.256
CNR	14 ± 4	14 ± 4	13 ± 3	14 ± 4	0.602
SNR	9 ± 2	10 ± 2	9 ± 1	9 ± 2	0.353
AS (n = 33)
Coronary attenuation (HU)	355 ± 37	354 ± 33	375 ± 52	336 ± 44	0.296
Image noise	40 ± 7	40 ± 6	38 ± 12	38 ± 6	0.676
CNR	16 ± 4	16 ± 4	17 ± 4	18 ± 2	0.635
SNR	10 ± 2	10 ± 2	11 ± 3	10 ± 2	0.261

Note–Values are presented as means ± standard deviation.

High pitch = prospective ‘high pitch’ scan protocol; AS = prospective ‘adaptive sequence’ scan protocol; SD = standard deviation; CNR = contrast-to-noise ratio; SNR = signal-to-noise ratio.