Ultra-low-dose CT coronary angiography using 128-slice dual source CT with low concentration contrast agent: initial experience.

Abstract

To optimize and evaluate an ultra-low-dose (ULD) technique for CT coronary angiography (CTCA). Eighty-two patients were randomly divided into two groups. ULD and routine CTCA were performed in groups A and B. Image quality, radiation dose and contrast agent were evaluated. The effective dose (ED) was 0.20±0.01mSv for the ULD technique, a decrease of 87% (t=-21.182, P<0.001) compared with the control group. The total iodine content was 8.10±0g, a decrease of 62% (t=-73.458, P<0.001) compared with 21.10±1.15g for the control group. The assessment rates for both groups were the same (99.26 vs 99.64%, χ 2 =0.727, P=0.394). The contrast-to-noise ratio was 19.31±7.95 for group A and 20.73±5.07 for group B: the difference was not statistically significant (t=-1.678, P=0.095). Using an ultra-low radiation dose and contrast agent technique, while maintaining an assessable image and improving the safety of the medical examination, was a feasible and reliable method for CTCA.