Table 1.

Comparison of quantitative image analysis by Wilcoxon test

	Standard CTA		DS-CTA		P
	Median	IQR	Median	IQR
Ascending aorta
Mean aortic density	288	260–365	360	325–412	0.043
Noise	16	14–21	27	23–31	0.038
SNR	17	15–24	15	13–17	0.073
CNR	14	13–21	13	11–14	0.091
Aortic arch
Mean aortic density	284	259–391	405	338–448	0.018
Noise	15	13–18	25	20–29	0.031
SNR	21	17–24	17	12–20	0.113
CNR	17	13–25	14	11–19	0.087
Descending aorta
Mean aortic density	281	244–401	381	314–415	0.054
Noise	14	12–17	23	19–29	0.034
SNR	20	15–31	15	12–22	0.076
CNR	16	12–27	13	10–18	0.129
Diaphragmatic aorta
Mean aortic density	279	252–372	371	324–427	0.016
Noise	16	14–23	31	27–34	<0.0001
SNR	19	13–25	13	10–16	0.0008
CNR	15	11–21	11	9–14	0.002
Origin of renal arteries
Mean aortic density	274	257–385	350	323–425	0.027
Noise	17	15–24	33	25–36	<0.0001
SNR	18	12–22	13	9–17	0.0004
CNR	14	11–19	11	8–14	0.0007

P < 0.05 is deemed statistically significant.

Quantitative parameters are reported as median and IQR for standard CTA and DS-CTA at the level of 1) ascending aorta above the aortic valve, 2) aortic arch at the origin of the brachiocephalic trunk, 3) thoracic descending aorta at the level of pulmonary trunk, 4) thoracic descending aorta at the diaphragm, 5) abdominal aorta at the level of the renal arteries.

CTA, computed tomography angiography; DS-CTA, dual-source computed tomography angiography; IQR, interquartile range; SNR, signal-to-noise ratio; CNR, contrast-to-noise ratio.