Keywords:
Case-control study, Retrospective, Image verification, Contrast agent-intravenous, CT-Angiography, CT, Vascular, Contrast agents, Arteries / Aorta, Performed at one institution
Authors:
Y. Ohka1, K. Takegami1, S. Kudomi1, T. uehara1, S. Tokurei2, M. Okada 1, T. Nomura1, K. miyoshi1; 1Yamaguchi/JP, 2Fukuoka/JP
DOI:
10.26044/ecr2020/C-08958
Results
Fig. 4 summarizes comparisons of body weight, iodine doses, injection rates, duration times, CTDIvol values, averaged CT values, SD and SNR between standard and 70-kV aortic CTA. Fig. 5 indicated the relationships between the body weight and the CTDIvol. were consistent between the standard CTA protocol and 70-kV aortic CTA with low-concentration CM of 140 mg/mL.
The averaged CT values at the aortic arch and descending aorta were 455.3±52.0 and 448.2±53.3 HU in the standard aortic CTA and 435.2±47.4 and 426.6±45.4 HU in 70-kV aortic CTA. The 70-kV aortic CTA with low-concentration CM of 140 mg/mL provided sufficient contrast enhancements equivalent to standard aortic CTA, while reducing the iodine dose by about half. Fig. 6 indicated the CT values and the SNR, which were plotted as a function of the body weight, at the level of top of the aortic arch and descending aorta. However, the CT values in the 70-kV aortic CTA were slightly smaller than that of the standard CTA, especially for the light-weight patients. The relationships between the body weight and the observed CT values varied depending on the tube voltage [5,6].
Fig. 7 shows the relationships between the CT values of the residual CM at the right subclavian vein and iodine concentrations. In the 70-kV CTA with low-concentration CM of 140 mg/mL, the CT values of the residual CMs were significantly lower than those of the high-concentration CMs over 300 mg/mL. The aortic CTA with the low-concentration CM may be effective to reduce streak artifacts from residual high-attenuation CM, while arterial attenuation is maintained.