Effect of different injection rates of contrast medium on hepatic perfusion by using multi-slice spiral CT

Objective To access the effect of different injection rates of contrast medium on hepatic perfusion by using multi-slice spiral CT (MSCT). Methods Sixty volunteers underwent liver dynamic CT scan, they were divided into three groups according to different injection rate of contrast medium (4 ml/s, 5 ml/s, and 7 ml/s, respectively). Their hepatic perfusion parameters were calculated and the results were compared between the three groups. Results There are five perfusion data: hepatic arterial perfusion(HAP), hepatic portal perfusion(HPP), total liver perfusion(TLP), hepatic arterial perfusion index(HPI), hepatic portal perfusion index(PPI). There is no significant difference of all indexes when compared 4 ml/s to 5 ml/s group, and 5 ml/s to 7 ml/s group, whereas HAP, HPP and TLP of 4 ml/s group were significant higher than those of 7 ml/s group. HAP:(0.37±0.16) ml·min -1 ·ml -1 vs (0.26±0.10) ml·min -1 ·ml -1 , t=0.105, P=0.010; HPP: (0.68±0.19) ml·min -1 ·ml -1 vs (0.51±0.13) ml·min -1 ·ml -1 , t=0.172, P=0.001; TLP: (1.05±0.30) ml·min -1 ·ml -1 vs (0.77±0.18) ml·min -1 ·ml -1 , t=0.277, P=0.001.Conclusion When evaluate liver perfusion with MSCT, the higher the injection rate of contrast medium, the lower the perfusion data. In clinical practice, perfusion effect, security and condition of patient should thought over to select a proper injection rate. To this study, 5 ml/s is enough.