The Application of Lower Tube Voltage and Fewer Contrast Agents for Hepatic Enhanced CT Scanning

Objective: To explore the feasibility of lower tube voltage (110kVp) and fewer contrast agent (1.0 mL/kg) for hepatic enhanced CT scanning. Methods: 116 cases of patients, BMI 〈 25, underwent hepatic enhanced CT scanning were randomly divided into two groups, 58 cases for each. Group A: tube voltage 110 kV, and contrast agent being iopamidol (300mgI/mL), total contrast agent 1.0mL/kg, using sinogram affirmed iterative reconstruction (SAFIRE). Group B: tube voltage 130 kV, and contrast agent being iopamidol (300mgl/mL), total contrast agent 1.2 mL/kg, using filtered back projection (FBP). Abdominal aorta CT value in aorta phase, portal vein CT value in portal vein phase and three-phase (aorta phase, portal vein phase, delay phase) of the right lobe were measured, then the contrast to noise ratio (CNR), signal to noise ratio (SNR), and effective radiation dose (ED) were recorded. All the images of the two groups were given subjective ratings, and the statistical analysis was made for all the above indicators between the two groups. Results: There were no significant difference in SNR and CNR between the two groups (P > 0.05, respectively). There were no significant difference in the hepatic parenchymal CT value of the right lobe in three-phase and the abdominal aorta CT value in arterial phase between the two groups (P > 0.05, respectively). The portal vein CT value of group A was lower than that in group B (P < 0.05, significantly). The total ED of three-phase in group A was (9.88 ±3.56) mSv, it was lower than group R, (13.91 ±4.71)mSv (P < 0.001, significantly). Compared with group B, the total contrast agent dose of group A was reduced by 17%. Conclusion: In hepatic enhanced CT scanning, when using lower tube voltage (110 kVp), fewer contrast dose (1.0 mL/kg), and simultaneous iterative reconstruction technique with 128 slice spiral CT, it can provide better image quality, and reduce the ED and iodine intake of the human body.