Influence of contrast agent's dose and injection rate on hepatic perfusion CT: an experimental study

Objective To investigate the influence of various doses of contrast agent and injection rates on hepatic perfusion imaging using slope method. Methods Hepatic perfusion CT was performed in 6 dogs with different doses of contrast agent (0.5,1 ml/kg) and different injection rates(3,5,7,9 ml/s). Hepatic arterial perfusion (HAP), portal venous perfusion (PVP) and hepatic perfusion index (HPI) were calculated with special software. Results With the dose of 0.5 ml/kg of body weight, HAP and PVP at the injection rate of 3 ml/s were significantly lower than that of other injection rates ( P 0.05 ). HPI dropped slightly with increasing injection rate.With the dose of 1 ml/kg of body weight, no significant difference was found in HAP and HPI at different injection rates ( P 0.05). PVP rose at first and then dropped. Conclusion When slope method is used in hepatic perfusion imaging, the dose of contrast agent and injection rate have some influence on hepatic perfusion parameters.