Table 3. Image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in filtered back projection (FBP) and sinogram affirmed iterative reconstruction algorithm (SAFIRE) series at 70 kVp dual-source CT (DSCT) angiography.

Region of interest	Image noise (HU), mean±SD			SNR, mean±SD			CNR, mean±SD
	FBP	SAFIRE	P	FBP	SAFIRE	P	FBP	SAFIRE	P
Ascending aorta	34.06±6.99	22.07±5.57	<0.05	17.16±7.11	28.33±10.28	<0.05	17.01±7.37	28.11±10.65	<0.05
Pulmonary trunk	32.85±5.78	21.55±5.23	<0.05	15.28±5.51	26.02±9.72	<0.05	15.14±5.65	25.80±9.78	<0.05