Published in:
01-11-2010 | Vascular-Interventional
Comparison of standard- and low-tube voltage MDCT angiography in patients with peripheral arterial disease
Published in: European Radiology | Issue 11/2010
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Objective:
We investigated the effect of low-tube-voltage CT angiography with a reduced volume of contrast agent on qualitative and quantitative parameters and the radiation dose in patients with peripheral arterial disease.
Methods:
Eighty consecutive patients were divided into two groups; the protocol was 120 kVp and 1.8 ml/kg contrast agent (300 mgI/ml) in one group and 80 kVp and 1.2 ml/kg in the other. For quantitative analysis we calculated the mean arterial attenuation, the mean difference between maximum and minimum attenuation values, contrast-to-noise ratio (CNR), and figure of merit (FOM). For qualitative evaluation, we used visual scores.
Results:
There were no significant intergroup differences in mean arterial attenuation (120 vs. 80 kVp: 331.6 ± 61.6 vs. 354.9 ± 61.9 HU) and in the mean difference between maximum and minimum attenuation (120 vs. 80 kVp: 52.2 ± 25.5 vs. 61.5 ± 27.5 HU). While the mean CNR was significantly higher at 120 than 80 kVp (38.4 ± 18.8 vs. 31.1 ± 15.3), the mean FOM was not significantly different (120 vs. 80 kVp: 1.3 ± 1.5 vs. 1.2 ± 1.2), and there was no significant intergroup difference in visual scores. The mean dose-length product was significantly lower at 80 than 120 kVp (1,024.3 ± 151.3 vs. 1,464.7 ± 208.7 mGy·cm).
Conclusion:
The 80-kVp protocol allows for reduction of the radiation dose by approximately 30% and the volume of contrast agent by more than 30% without deterioration of vascular enhancement and image quality.