To explore the clinical value of the dual-low-dose with low tube voltage for head and neck CTA.

One hundred and sixty patients who were clinically suspected head and neck vascular disease underwent CTA procedure were propective selected, and whose body mass index (BMI) was also lower than 25 kg/m². Forty cases were randomly selected as conventional group(120 kV,150 mAs, iodine 320 mg/ml), the other 120 cases were as the low dose group. The low dose group divided into three subgroups according to the random number table method, which were low iodine group (37 cases; 120 kV,150 mAs, iodine 270 mg/ml), low tube voltage group (42 cases; 100 kV,150 mAs, iodine 320 mg/ml) and low iodine and tube voltage group (41 cases; 100 kV,150 mAs, iodine 270 mg/ml). The carotid bifurcated CT value, standard deviation (SD), signal-to-noise ratio (SNR), iodine intake and effective radiation dose (ED) of the four groups were recorded,all data undertook statistical analysis useing one-way ANOVA. Meanwhile, the subjective image quality score was applied to evaluate the image quality, and the differences among groups were compared by Wilcoxon signed ranks test.

The image quality score were (2.85±0.19),(2.33±0.34),(2.26±0.32),(2.87±0.22) in the four groups, and there was no statistical difference between groups(P>0.05).The carotid bifurcated CT value were respectively (380±30),(314±27),(514±52) and (425±28) HU in conventional, low iodine, low tube voltage and dual-low-dose groups, and the iodine intake were (18.85±2.10), (15.75±1.78), (18.53±1.98), (15.62±1.92) g, the ED of the four groups were (1.74±0.14), (1.73±0.11), (1.32±0.08) and (1.35±0.09) mSv, the difference were all statistically significant (P<0.01). Furthermore, the iodine intake and the effective radiation dose in dual-low-dose group were significantly lower than the conventational group.

Head-and-neck CTA with dual-low-dose scan can provide same quality images as using 100 kV and high dose iodine contrast agent, and which also significantly reduced the ED and iodine intake greatly. Thus, this scanning program has great clinical value.

Tomography, X-ray computed; Radiation dosage; Comparative study