Aortic dual-energy CT angiography with low contrast medium injection rate

The contrast medium (CM) induced nephropathy required new CT imaging protocol. This study evaluated the feasibility of low contrast medium (CM) volume and injection flow using aortic dual-energy CT (DECT) angiography with non-linear blending technique. Sixty patients were randomly assigned to two groups: control group (n=30), single-energy CT 70 ml CM at injection rate of 5 ml/s; study group (n=30), DECT mode, 0.5 ml per kg of patient weight CM at injection rate=(weight × 0.5 ml/kg)/(4+scan time). Non-linear blending technique was used for dual-energy images. Mean attention, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of aorta were compared. The level of visible renal artery branches was scored. There was no significant difference between the two groups in the mean aortic attention, SNR and CNR (all P > 0.05). Significant difference was showed in CM injection rate (p < 0.001) and volume (P < 0.001). The renal artery score had no statistically significant difference (P=0.771). Compared conventional scan and CM injection protocol, DECT with non-linear blending technique maintained the image quality of aortic CT angiography with reduced CM volume and flow rate, which could reduce the risks associated with CM injection.